Botox is a brand-name prescription drug that’s approved to manage several different conditions. Specifically, Botox is FDA-approved for the following uses:

  • prevent headaches in adults with chronic migraine
  • treat overactive bladder (OAB) in adults with urinary incontinence, urgency, and frequency
  • treat urinary incontinence that’s caused by a nerve disorder, such as multiple sclerosis (MS) or spinal cord injury, in adults
  • treat upper or lower limb spasticity (involuntary muscle contractions) in adults
  • treat upper or lower limb spasticity in children ages 2 years and older
  • treat cervical dystonia (involuntary muscle spasms in the neck) in adults
  • treat blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms); for this purpose, Botox can be used in adults and children ages 12 years and older
  • treat strabismus (crossed eyes or misaligned eyes) in adults and children ages 12 years and older
  • treat severe axillary hyperhidrosis (excessive underarm sweating) in adults

Botox is approved to treat each of these conditions in certain situations. To learn more about using Botox for these conditions, see the “Botox for chronic migraine” and “Other uses for Botox” sections below.

Botox active drug, form, and administration

Botox contains the active drug onabotulinumtoxinA. It’s made from a toxin that’s produced by Clostridium botulinum bacteria. Botox is a type of drug called a neurotoxin.

Botox comes as a powder inside single-use vials. It’s mixed into a solution and given as an injection by healthcare providers. Botox is available in two strengths: 100 units and 200 units.

For most of its uses, Botox is given by intramuscular injection (injection into a muscle). It’s injected into muscles in different areas of the body, depending on the condition being treated.

For OAB and urinary incontinence due to nerve disorders, Botox is injected into the detrusor muscle of the bladder. This injection is done using a thin tube called a cystoscope that’s inserted into the bladder.

And for excessive underarm sweating, Botox is injected into the skin of the armpit.

Effectiveness

In several clinical studies, Botox was effective for all of its approved uses. To learn more about the effectiveness of this drug, see the “Botox for chronic migraine” and “Other uses for Botox” sections below.

Botox vs. Botox Cosmetic

Botox and Botox Cosmetic are two different medications. While they both contain the same active drug, Botox Cosmetic is given in lower doses than Botox is given. And it’s used for cosmetic reasons rather than for medical conditions.

Specifically, Botox Cosmetic is FDA-approved to reduce the following types of wrinkles:

Like Botox, Botox Cosmetic comes as a powder inside single-use vials. And it’s also mixed into a solution and given by injection. Botox Cosmetic is available in these two strengths: 50 units and 100 units.

Botox Cosmetic injections are given by a healthcare provider into certain muscles in your forehead or around your eyes.

Botox is available only as a brand-name medication. It’s not currently available in generic form. (A generic drug is an exact copy of the active drug in a brand-name medication.)

The Food and Drug Administration (FDA) approves prescription drugs such as Botox to treat certain conditions. Botox is approved to treat chronic migraine in adults. In addition, the drug is approved to treat other conditions, which are described in the “Other uses for Botox” section below.

What is migraine?

Migraine is a neurologic condition than can cause severe, throbbing, disabling headaches. The headaches typically occur on one side of your head and last for several hours. But sometimes, they can last for days.

With migraine headaches, you’ll usually also have nausea and increased sensitivity to light or sound. Some people also have a sensory aura before or during the headache. Sensory auras may involve changes in your vision, such as having blind spots or seeing light flashes or zigzag lines. With migraine, it’s also possible to have tingling or buzzing sensations and to have trouble speaking.

Migraine is considered to be chronic if you have headaches that last at least 4 hours on 15 or more days each month.

Botox is used in chronic migraine management to help prevent headaches. The drug works by stopping certain nerves in your body from sending signals. The nerves affected by Botox are those involved in causing migraine and producing pain during a migraine headache.

What to expect with Botox for migraine

For migraine management, you’ll typically receive Botox injections once every 3 months. During your injection visits, your doctor will give you multiple injections of the drug. They’ll typically inject Botox into muscles in the following areas:

  • your forehead
  • the area around your temples
  • the back of your neck

Botox can help reduce the number of migraine attacks you have and how long they last. But the drug won’t completely stop your migraine headaches. In addition, Botox doesn’t work right away, and it doesn’t work for everyone.

Some people start to see an improvement in their migraine headaches just 2 to 4 weeks after their first set of Botox injections. But it can take two sets of injections and up to 6 months of treatment before you get the maximum effect from Botox.

Effectiveness for chronic migraine

In two clinical studies, Botox was effective in preventing migraine headaches. In these studies, adults with chronic migraine received either Botox or a placebo (treatment with no active drug). Treatment was administered as two sets of injections, which were each given 3 months apart.

After 6 months of treatment:

  • people who were given Botox had an average of 7.8 to 9.2 fewer migraine days per month than they had before treatment
  • people who were given the placebo had an average of 6.4 to 6.9 fewer migraine days per month than they had before treatment

The study also showed that, on average:

  • people who were given Botox had 107 to 134 fewer hours of headache per month
  • people who were given the placebo had 70 to 95 fewer hours of headache per month

Botox and children with chronic migraine

Botox isn’t approved for use in children with chronic migraine. It’s only approved for use in adults ages 18 years and older with this condition.

One study looked at children and adolescents who were younger than 18 years of age with chronic migraine. The study didn’t find Botox to be effective in preventing migraine in this age group.

The Food and Drug Administration (FDA) approves prescription drugs such as Botox to treat certain conditions. Botox may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

In addition to chronic migraine in adults (see the previous section), Botox is approved to treat:

  • overactive bladder (OAB) in adults with urinary incontinence, urgency, and frequency
  • urinary incontinence that’s caused by a nerve disorder, such as multiple sclerosis (MS) or spinal cord injury, in adults
  • upper or lower limb spasticity (involuntary muscle contractions) in adults
  • upper or lower limb spasticity in children ages 2 years and older
  • cervical dystonia (involuntary muscle spasms in the neck) in adults
  • blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms); for this purpose, Botox can be used in adults and children ages 12 years and older
  • strabismus (crossed eyes or misaligned eyes) in adults and children ages 12 years and older
  • severe axillary hyperhidrosis (excessive underarm sweating) in adults

Botox for overactive bladder

Botox is FDA-approved to treat overactive bladder (OAB) in adults with the following urinary symptoms:

  • urge incontinence (involuntary leaking of urine)
  • urgency
  • frequency

OAB is caused by uncontrollable spasms of a muscle in your bladder wall. This muscle is called the detrusor muscle. When the detrusor muscle contracts, it squeezes your bladder. With OAB, detrusor muscle spasms cause you to have sudden and frequent urges to urinate. And these urges can sometimes lead to incontinence if you can’t get to a toilet quickly enough.

Botox is used to treat OAB when drugs called anticholinergics either caused bothersome or severe side effects, or they didn’t work well enough. Examples of anticholinergic drugs used for OAB include oxybutynin (Ditropan XL) and tolterodine (Detrol).

Botox can help reduce the number of urinary incontinence episodes you have. And the drug can also decrease the number of times per day that you need to urinate.

To treat OAB, Botox is injected directly into the detrusor muscle in your bladder. The drug works by stopping nerves from sending signals that cause this muscle to contract. These injections are given through a thin tube called a cystoscope that’s inserted into your bladder.

The effect of Botox injections for OAB lasts at least 12 weeks. After that point, the drug’s effect starts to wear off and repeat treatment may be needed. But in clinical studies, the drug’s effect lasted for an average of 24 weeks before repeat treatment was needed.

Effectiveness for overactive bladder

In two clinical studies, Botox was effective in treating OAB. In these studies, people were given one set of either Botox injections or placebo injections. (A placebo is a treatment that contains no active drug.) Either treatment was injected into the detrusor muscle.

Twelve weeks after treatment was given:

  • people who received Botox had, on average, 2.5 to 3 fewer episodes of incontinence per day than they had before treatment
  • people who received the placebo had, on average, 0.9 to 1.1 fewer episodes of incontinence per day than they had before treatment

In addition, the study showed that:

  • people who received Botox urinated, on average, 1.9 to 2.3 fewer times per day than they did before treatment
  • people who received the placebo urinated, on average, 0.6 to 0.9 fewer times per day than they did before treatment

Botox for urinary incontinence caused by a nerve disorder

Botox is FDA-approved to treat urinary incontinence that’s caused by a neurologic condition (nerve disorder). Examples of these nerve disorders include multiple sclerosis (MS) and spinal cord injury. For this condition, Botox can be used in adults.

With urinary incontinence, you have involuntary leaking of urine. This is a common problem in people with certain nerve disorders. The incontinence happens because nerves that aren’t functioning correctly send inappropriate signals to the muscle in your bladder wall. This muscle is called the detrusor muscle. The inappropriate signals make your detrusor muscle contract uncontrollably. And this squeezes your bladder and causes urinary incontinence.

Botox is used for this condition when drugs called anticholinergics either caused bothersome or severe side effects, or they didn’t work well enough. Examples of anticholinergic drugs used for this purpose include oxybutynin (Ditropan) and tolterodine (Detrol).

To treat this type of urinary incontinence, Botox is injected directly into the detrusor muscle in your bladder. The drug works by stopping nerves from sending signals that cause this muscle to contract. These injections are given through a thin tube called a cystoscope that’s inserted into your bladder.

Effectiveness for urinary incontinence that’s caused by a nerve disorder

In two clinical studies, Botox was effective in treating urinary incontinence that’s caused by a nerve disorder. People were given one set of either Botox injections or placebo injections. (A placebo is a treatment that contains no active drug). Either treatment was injected into the detrusor muscle.

Six weeks after the treatment was given:

  • people who received Botox had, on average, 19.6 to 19.9 fewer episodes of incontinence per week than they had before treatment
  • people who received the placebo had, on average, 10.6 to 10.8 fewer episodes of incontinence per week than they had before treatment

Botox for upper and lower limb spasticity

Botox is FDA-approved to treat certain types of muscle spasticity. With this condition, your muscles contract involuntarily and become stiff. Upper and lower limb spasticity can cause stiffness in your elbows, hands, fingers, ankles, or toes. Muscle spasticity can be painful, and it can make it difficult for you to do daily activities.

Specifically, Botox is approved to treat:

  • upper and lower limb spasticity in adults
  • upper and lower limb spasticity in children ages 2 to 17 years

Upper or lower limb spasticity may occur after someone has a stroke. In fact, these conditions can affect between 20% and 30% of people who’ve had a stroke.

But limb spasticity may also be caused by nerve disorders, such as multiple sclerosis (MS) and cerebral palsy (CP). Brain or spinal cord injury can also result in limb spasticity. All these conditions can damage nerves in your brain, causing them to malfunction and result in limb spasticity.

To treat limb spasticity, Botox is injected into certain muscles in the affected arm, hand, or leg. The drug works by stopping nerves from sending signals that are causing the muscles to be spastic. This action of Botox allows the muscles to relax.

The effect of Botox injections for limb spasticity typically lasts about 12 weeks. After that point, the drug’s effect wears off and repeat treatment may be needed.

Effectiveness for upper and lower limb spasticity

In several clinical studies, Botox was effective in treating limb spasticity. In these studies, people were given one set of either Botox injections or placebo injections. (A placebo is a treatment that contains no active drug.) Either treatment was injected into their affected muscles.

Researchers measured how stiff people’s elbows, wrists, fingers, thumbs, or ankles were using a scale called the Ashworth scale. On this scale, a score of zero indicates no muscle stiffness. A score of 4 indicates that an affected body part is completely rigid in either a bent or straightened position. Lower scores show reduced spasticity and stiffness.

Effectiveness in adults with upper or lower limb spasticity

In adults, studies involved people with upper or lower limb spasticity that followed a stroke. At 6 weeks after treatment:

  • adults who received Botox had their Ashworth scores lowered by between 0.5 and 2 points
  • adults who received the placebo had their Ashworth scores lowered by between 0 and 1 points

The reduced number of points seen in these groups of people varied depending on the body part affected and the dose of treatment that was given.

Effectiveness in children with upper or lower limb spasticity

One study involved children with upper limb spasticity that was caused by either cerebral palsy (CP) or stroke. Another study involved children with lower limb spasticity that wasn’t related to CP.

In these studies, at 6 weeks after treatment:

  • children who received Botox had their Ashworth scores lowered by between 1.01 and 1.92 points
  • children who received the placebo had their Ashworth scores lowered by between 0.8 and 1.21 points

The reduced number of points seen in these groups of children varied depending on the body part affected and the dose of treatment that was given.

Botox for cervical dystonia

Botox is FDA-approved to treat cervical dystonia, which is also called spasmodic torticollis. For this purpose, Botox can be used in adults.

With cervical dystonia, you have involuntary muscle spasms in your neck. The spasms cause repetitive, uncomfortable, twisting movements in your head or neck. These movements place your head into an abnormal position and cause pain in your neck.

To treat cervical dystonia, Botox is injected into the affected muscles in your neck or upper back. The drug works by stopping nerves from sending the signals that cause those muscles to contract. This allows the muscles to relax.

The effect of Botox injections for this condition typically lasts about 12 weeks. After that, the effect wears off and repeat treatment may be needed.

Effectiveness for cervical dystonia

In a clinical study, Botox was effective in treating cervical dystonia. People were given one set of either Botox injections or placebo injections. (A placebo is a treatment that contains no active drug.) Either treatment was injected into the affected muscles.

Researchers assessed the severity of people’s abnormal head positioning using a 54-point scale called the Cervical Dystonia Severity Scale (CDSS). A higher CDSS score indicates a more severe problem with head position than a lower score indicates.

At 6 weeks after treatment:

  • 51% of people who received Botox had an overall improvement in their cervical dystonia
  • 31% of people who received the placebo had the same result
  • in people who received Botox, their average CDSS score was lowered by 1.3
  • in people who received the placebo, their CDSS score was lowered by 0.3

Botox for blepharospasm

Botox is FDA-approved to treat blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms). The drug is approved for this use in adults and children ages 12 years and older.

Dystonia describes a range of movement disorders that are caused by problems with nerve messages sent to your muscles. This condition can affect one or many parts of your body.

With blepharospasm, you have muscle spasms in your eyelids. These spasms cause excessive and uncontrollable blinking of both eyes. In severe cases of blepharospasm, you may not be able to open your eyes for several minutes at a time. The condition can irritate your eyes, and it can make them more sensitive to light.

To treat blepharospasm, Botox is injected into the affected muscles in your upper and lower eyelids. The drug works by stopping nerves from sending the signals that are causing those muscles to contract. This weakens the muscles and stops them from causing excessive blinking.

For blepharospasm, Botox’s effect typically lasts about 12 weeks before it wears off. At that time, repeat treatment can be done if needed.

Effectiveness for blepharospasm

In clinical studies, Botox was effective in treating blepharospasm. The majority of people given Botox for this condition had improvement after treatment.

In one study, 25 out of 27 people using Botox had their condition improve within 48 hours of receiving the drug.

Botox for strabismus

Botox is FDA-approved to treat strabismus in adults and children ages 12 years and older.

Strabismus affects one or more of the muscles on the outside of one eyeball. It causes the affected muscles to contract more strongly than other muscles. This causes the eyeball to turn, so that your eyes are crossed or misaligned and they don’t look in the same direction.

To treat strabismus, Botox is injected into the muscles that are pulling your eyeball in the wrong direction. The drug works by stopping nerves from sending signals that are causing the muscles to contract and pull your eyeball.

Botox’s effect for this condition typically lasts about 12 weeks before it wears off. At that time, repeat treatment may be needed.

Effectiveness for strabismus

In a clinical study, Botox was effective in treating strabismus in people who were given one or more injections of the drug.

At 6 months after receiving treatment, 55% of people had an improvement in their condition.

Botox for severe axillary hyperhidrosis

Botox is FDA-approved for use in adults with severe primary axillary hyperhidrosis (excessive underarm sweating). Botox can be used to treat this condition when antiperspirants applied to the underarms don’t work well enough to control sweating.

With hyperhidrosis you sweat excessively. The sweating can cause discomfort, embarrassment, and anxiety. And it can lead to problems with your emotional well-being, relationships, social life, and daily activities.

With primary axillary hyperhidrosis, there’s no apparent cause for the excessive sweating, such as an underlying health condition.

To treat severe primary axillary hyperhidrosis, Botox injections are given into the skin in your armpits. The drug works by stopping nerves from sending signals that activate the sweat glands in that area. It’s not known if Botox is safe or effective for treating excessive sweating in other parts of the body.

If needed, Botox injections can be repeated after symptoms return. For this purpose, repeat Botox treatment is typically done at least 8 weeks after the first injection.

Effectiveness for severe axillary hyperhidrosis

In two clinical studies, Botox was effective in treating axillary hyperhidrosis. People were given one set of either Botox injections or placebo injections. (A placebo is a treatment that contains no active drug.) The injections were administered into their armpits.

Researchers assessed the severity of people’s sweating using a 4-point scale called the Hyperhidrosis Disease Severity Scale (HDSS). On this scale, a score of 1 indicates that underarm sweating is never noticeable, and it never interferes with daily activities. A score of 4 indicates that underarm sweating is intolerable, and it always interferes with daily activities.

Researchers also measured the amount of sweat produced by people in the study. This was done by weighing a piece of filter paper that was held in their armpits for 5 minutes.

At 4 weeks after treatment, the study showed that HDSS scores were reduced by at least 2 points in:

  • 49% to 55% of people who received Botox
  • 6% of people who received the placebo

In addition, sweat production was reduced by at least half in:

  • 81% to 91% of people who received Botox
  • 36% to 41% of people who received the placebo

Botox and children

Botox is FDA-approved to treat the following conditions in children:

  • upper or lower limb spasticity (involuntary muscle contraction) in children ages 2 years and older
  • blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms) in children ages 12 years and older
  • strabismus (crossed eyes or misaligned eyes) in children ages 12 years and older

To read more about these uses of Botox and its effectiveness in treating them, see the sections above for each condition.

Off-label uses for Botox

In addition to the uses listed above, Botox may be used off-label for other purposes. Off-label drug use is when a drug that’s approved for one or more uses is prescribed for a different one that’s not approved. Below are examples of off-label uses for Botox.

Botox for tension headaches

Botox isn’t FDA-approved to treat tension headaches. However, sometimes it’s used off-label to help prevent chronic tension headaches.

Tension headaches are also called stress headaches. They tend to affect both sides of your head. And they may occur along with stiffness in your neck or shoulders. Unlike migraine headaches, tension headaches don’t typically cause nausea. But people with tension headaches may be more sensitive to light and sound.

With chronic tension headaches, you have tension headaches on at least 15 days each month, for at least 3 months in a row.

Botox is very effective in preventing chronic migraine headaches. So it’s not surprising that the drug has also been studied for preventing chronic tension headaches. A recent review of research suggests that Botox could be effective for this purpose. But more research is needed to know for sure if the treatment is effective.

If you have tension headaches, talk with your doctor. They can help you figure out possible causes of your headaches and suggest appropriate treatment options.

Botox for anal fissures

Botox isn’t FDA-approved to treat anal fissures. However, the drug is sometimes used off-label for this condition.

An anal fissure is a tear or crack in the tissue that lines your anus. These fissures cause pain and bleeding during and after bowel movements.

Muscle spasms in the anal sphincter (ring of muscles around your anus) may be associated with causing anal fissures. The muscle spasms may also prevent anal fissures from healing. So anal fissures are typically treated with medications that help to relax the anal sphincter.

A recent review of the causes and treatments of anal fissures suggests that Botox may be an effective treatment option. According to this review, injecting Botox into a certain area of the anal sphincter can allow fissures to heal in 60% to 80% of cases. However, in up to 42% of cases, the fissures may come back.

If you’re interested in using Botox to treat an anal fissure, talk with your doctor. They can recommend appropriate treatment options for your condition.

Botox for depression

Botox isn’t FDA-approved to treat depression. However, there’s a growing amount of research that suggests Botox may be effective for treating this condition.

For example, one 2014 study looked at 30 people with depression. Another 2014 study looked at 85 people with depression. These studies showed that Botox may be effective in treating depression. However, more studies are needed to confirm the drug’s effectiveness in treating this condition.

If you’re interested in using Botox to treat depression, talk with your doctor. They can recommend appropriate treatment options for your condition.

Botox is used to manage several different conditions. Specifically, Botox is FDA-approved for the following uses:

  • prevent headaches in adults with chronic migraine
  • treat overactive bladder (OAB) in adults with urinary incontinence, urgency, and frequency
  • treat urinary incontinence that’s caused by a nerve disorder, such as multiple sclerosis (MS) or spinal cord injury, in adults
  • treat upper or lower limb spasticity (involuntary muscle contractions) in adults
  • treat upper or lower limb spasticity in children ages 2 years and older
  • treat cervical dystonia (involuntary muscle spasms in the neck) in adults
  • treat blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms); for this purpose, Botox can be used in adults and children ages 12 years and older
  • treat strabismus (crossed eyes or misaligned eyes) in adults and children ages 12 years and older
  • treat severe axillary hyperhidrosis (excessive underarm sweating) in adults

About the conditions Botox treats

Botox is used to treat several seemingly unrelated conditions. But the feature that each of these conditions has in common is that they all result from a nerve problem. Specifically, these conditions occur because certain nerves don’t function properly. Instead, the nerves become overactive and send excessive signals.

For example, with migraine, nerves in your brain send signals that lead to migraine attacks. With excessive sweating, nerves in your skin send signals that over-activate your sweat glands. With abnormal muscle contractions, certain nerves send signals that cause your muscles to contract in an inappropriate and uncontrollable way.

What Botox does

Botox is made from a toxin that’s produced by Clostridium botulinum bacteria. It’s a type of drug called a neurotoxin. Botox works by stopping nerves from functioning.

Normally, nerves communicate with other parts of your body, such as your muscles. Your nerves do this by releasing a neurotransmitter (chemical messenger) called acetylcholine. Botox works by stopping nerve endings from releasing acetylcholine. This leaves the nerves temporarily unable to send signals.

When it’s injected into specific muscles, Botox stops nerves from sending the signals that cause those muscles to contract or spasm. This weakens or paralyses the muscle. For example:

  • with limb spasticity, Botox stops the muscle contractions in your arm, hand, or leg that are causing stiffness
  • with cervical dystonia, Botox stops the muscle contractions in your neck that are causing abnormal head and neck position
  • with blepharospasm, Botox reduces blinking
  • with strabismus, Botox stops the affected muscles from turning your eye in the wrong direction
  • with urinary incontinence, Botox stops excessive muscle contractions in your bladder wall that cause urinary leakage
  • with migraine, Botox stops certain nerves from sending signals that are involved in causing migraine attacks

When it’s injected into your skin, as it is with excessive sweating, Botox stops certain nerves from sending signals. These signals activate your sweat glands and cause you to sweat.

Botox’s effect wears off gradually as your nerves develop new endings and start to release acetylcholine again. This process typically takes about 3 months. But if recommended by your doctor, Botox injections can be repeated when the drug’s effect goes away.

How long does it take for Botox to work?

Botox starts to have its effect on nerve endings in your body within 24 to 72 hours after it’s injected. But it typically takes up to 2 weeks before the drug has its full effect and you notice a difference in your symptoms. However, for some people, it can take longer than 2 weeks for this to occur.

Botox can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Botox. These lists don’t include all possible side effects.

For more information on the possible side effects of Botox, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to report to the FDA a side effect you’ve had with Botox, you can do so through MedWatch.

Mild side effects

Mild side effects of Botox can include:*

  • pain, tenderness, redness, swelling, bruising, bleeding, or infection at Botox injection sites
  • unwanted muscle weakness near Botox injection sites
  • nausea
  • fever
  • achy muscles
  • upper respiratory tract infections, such as the common cold
  • headache
  • neck pain
  • drooping eyelids
  • dry eyes
  • dry mouth
  • painful urination and urinary tract infection (UTI) in people using Botox for urinary incontinence

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Botox. Side effects may vary depending on the condition treated. To learn about other mild side effects, talk with your doctor or pharmacist, or visit Botox’s Medication Guide.

Serious side effects

Serious side effects from Botox aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

  • Corneal ulceration (open sore on the clear covering over the front of the eye) that’s due to reduced blinking in people using Botox to treat blepharospasm. Symptoms can include:
    • eye pain and redness
    • blurred vision
    • watery eye
    • feeling that something is in your eye
    • white spot on the cornea (the front cover of the pupil and iris)
  • Urinary retention (inability to empty your bladder) in people using Botox to treat urinary incontinence. Symptoms can include:
    • burning sensation when urinating
    • difficulty urinating
    • frequently feeling like you need to urinate
  • Allergic reaction.*
  • Spread of toxin effects, which may lead to trouble breathing or swallowing that may be life threatening.*

* This serious side effect is explained in more detail below in “Side effect details.”
Botox has a boxed warning for spread of toxin effects. This is the most serious warning from the FDA. A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Side effects in children

Botox is approved for use in children with certain conditions. Below, we list these conditions and briefly describe the side effects seen in children who have them.

  • Upper and lower limb spasticity (involuntary muscle contraction). The most common side effect in children with these conditions is upper respiratory tract infection, such as the common cold. This side effect occurs more often in children with these conditions than it does in adults.
  • Blepharospasm (uncontrollable blinking) and strabismus (crossed eyes). Side effects of Botox in children with these conditions are similar to side effects in adults treated for these conditions.

Side effect details

You may wonder how often certain side effects occur with this drug. Here’s some detail on several of the side effects this drug may cause.

Spread of toxin effects

In some cases, Botox’s effects may spread away from the site where it’s injected. This can cause a serious condition called botulism, which is described further below.

In fact, Botox has a boxed warning for this spread of toxin effects. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Symptoms caused by botulism

Botulism may lead to symptoms such as:

  • lack of energy
  • muscle weakness all over your body
  • drooping eyelids
  • double vision
  • loss of bladder control
  • hoarse voice
  • trouble speaking
  • trouble breathing
  • trouble swallowing

Symptoms of botulism can occur hours, days, or weeks after you’ve had a Botox injection. But it’s not known for sure how often the symptoms occur in people using this drug. Be sure to tell your doctor if you develop any symptoms of botulism, even it’s not right after your Botox injection was given.

People with the highest risk of botulism symptoms from Botox are children who are treated for spasticity. Serious effects caused by the spread of Botox’s effect haven’t been reported in people given recommended doses of Botox for certain other conditions. These conditions are chronic migraine, excessive sweating, blepharospasm (uncontrollable blinking), and strabismus (crossed eyes or misaligned eyes).

What to do for symptoms caused by botulism

It’s important to note that breathing and swallowing problems caused by Botox can be life threatening. And the risk of these problems is higher in people who already have any breathing or swallowing problems.

If you have any trouble with breathing, swallowing, or speaking after having Botox injections, call your doctor right away. But if your symptoms feel life threatening, call 911 or your local emergency number.

In addition, if you have loss of strength, muscle weakness, blurred vision, dizziness, or drooping eyelids, you should avoid driving. And let your doctor know about these symptoms right away.

Pain after injection

You may have some pain after receiving a Botox injection. In fact, it’s common to have pain, tenderness, swelling, or bruising in areas where the drug is injected.

In clinical studies, between 2% and 4% of people who received Botox had injection site pain. In comparison, injection site pain occurred in up to 2% of people who received placebo injections. (A placebo is a treatment that contains no active drug.)

In these studies, some people also had other types of pain. For example, in people who received Botox for migraine:

  • 5% had headache; in comparison, 3% of people who received the placebo had headache
  • 9% had neck pain; in comparison, 3% of people who received the placebo had neck pain
  • 3% had muscle pain; in comparison, 1% of people who received the placebo had muscle pain
  • 3% had musculoskeletal pain, such as shoulder pain; in comparison, 1% of people who received the placebo had musculoskeletal pain
  • less than 1% had jaw pain; however, this side effect was more common with Botox than it was with the placebo

If you have pain of any kind after receiving a Botox injection, talk with your doctor. They can recommend how to best to manage your discomfort.

Allergic reaction

As with most drugs, some people can have an allergic reaction after receiving Botox. But it’s not known how often this occurs in people using the drug.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Botox. But call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Hair loss

You may have hair loss after receiving Botox, but this side effect isn’t very common. In fact, hair loss wasn’t reported during clinical studies of Botox.

However, a few cases of hair loss have been reported since Botox was approved for use and became available on the market. But it’s not known how often these cases of hair loss occurred. And it’s not known for sure if the hair loss was caused by Botox.

If you’re concerned about hair loss with Botox, talk with your doctor.

Botox is given during “treatment sessions.” During each session, you’ll likely receive several injections of the drug. The injections are given into different areas of the body, depending on the condition being treated.

Botox injection sites

For most of its uses, Botox is given by intramuscular injection (injection into a muscle). It’s injected into muscles in different areas of your body, depending on the condition being treated.

For OAB and urinary incontinence due to nerve disorders, Botox is injected into the detrusor muscle of the bladder. This injection is done using a thin tube called a cystoscope that’s inserted into your bladder.

And for excessive underarm sweating, Botox is injected into the skin of your armpit.

Injection sites for chronic migraine

For chronic migraine, you’ll receive two or more Botox injections in each of the following areas of your body:

  • lower part of your forehead, just above your nose and the inside edge of each eyebrow
  • middle of your forehead, above each eye
  • behind each temple, above the ear
  • back of your head, behind each ear
  • back of your neck, at the base of your skull on both your right and left side
  • between your shoulder and your neck on both your right and left side

Note: To learn about chronic migraine, see the “Botox for chronic migraine” section above.

Injection sites for other conditions

Below, we describe Botox injections sites for the following conditions:

  • Overactive bladder (OAB). For OAB, Botox injections are given into the wall of your bladder. The injections are given through a thin tube called a cystoscope that’s inserted into your bladder through your urethra. The procedure may be done under a local anesthetic* or general anesthetic.
  • Urinary incontinence that’s caused by a nerve disorder. As with OAB, Botox injections are given into the wall of your bladder for urinary incontinence. And these injections are also given through a cystoscope with either local or general anesthetic.
  • Upper limb spasticity. For upper limb spasticity, Botox injections are given just above the elbow, in the forearm, and near the thumb.
  • Lower limb spasticity. For lower limb spasticity, Botox injections are given in the calf.
  • Cervical dystonia. For cervical dystonia, Botox injections are given in the neck.
  • Severe axillary hyperhidrosis. For hyperhidrosis, Botox injections are given in the armpits.
  • Blepharospasm. For blepharospasm (uncontrollable blinking), Botox injections are given in the upper and lower eyelids.
  • Strabismus. For strabismus, Botox injections are given in the muscles that move your eye. This procedure may be done with a local anesthetic.*

* With a local anesthetic, a numbing medication is used in the area of the Botox injection so that you don’t feel pain.
† With general anesthetic, a medication is given that temporarily makes you unconscious so that you don’t feel pain.

For strabismus, limb spasticity, and cervical dystonia, your doctor will measure the electrical activity in your muscles before giving Botox injections. Doing this allows your doctor to determine exactly which muscles are affected. They can then place Botox injections precisely where they’re needed.

Note: To learn about the conditions listed above, see the “Other uses for Botox” section above.

It’s not known whether it’s safe to receive Botox injections while you’re pregnant. This drug hasn’t been studied in pregnant women. In animal studies, the drug did cause fetal harm when given to pregnant females. However, animal studies don’t always predict what will happen in humans.

If you’re pregnant or planning to become pregnant, talk with your doctor about whether Botox is right for you. And if you become pregnant after receiving a Botox injection, call your doctor right away.

It’s not known if it’s safe to have Botox injections during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Botox.

For more information about taking Botox during pregnancy, see the “Botox and pregnancy” section above.

It’s not known if Botox passes into human breast milk or if it affects how your body makes breast milk. And it’s also not known if the drug can affect a child who’s breastfed.

If you’re breastfeeding or plan to breastfeed, talk with your doctor about whether Botox is right for you.

The Botox dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re using Botox to treat
  • your age
  • other medical conditions you may have

The following information describes dosages that are commonly used or recommended. However, your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Botox comes as a powder inside single-use vials. It’s mixed with liquid to form a solution that’s given as an injection. You’ll receive Botox injections from a healthcare provider.

For most of its uses, Botox is given by intramuscular injection (injection into a muscle). It’s injected into muscles in different areas of your body, depending on the condition being treated.

For OAB and urinary incontinence caused by a nerve disorder, Botox is injected into the detrusor muscle of the bladder. This injection is done using a thin tube called a cystoscope that’s inserted into your bladder.

And for excessive sweating, Botox is injected into the skin of your armpit.

Botox is available in two strengths: 100 units and 200 units.

Dosage for chronic migraine

The recommended dosage of Botox for chronic migraine is 155 units. This total dose is given as 31 injections of 5 units each. The injections are given into recommended injection sites, which are described in the “How Botox is given” section above.

Botox treatment for chronic migraine is typically repeated once every 12 weeks.

Note: To learn more about chronic migraine, see the “Botox for chronic migraine” section above.

Dosage for overactive bladder

The recommended dosage of Botox for overactive bladder (OAB) is 100 units. This total dose is given as 20 injections of 5 units each. The injections are given 1 cm apart into your bladder wall. This injection procedure is described further in the “How Botox is given” section above.

Botox treatment for OAB may be repeated when the drug’s effect wears off. But each treatment session must be at least 12 weeks apart.

Note: To learn more about OAB, see the “Other uses for Botox” section above.

Dosage for urinary incontinence that’s caused by a nerve disorder

The recommended dosage of Botox for urinary incontinence that’s caused by a nerve disorder is 200 units. This total dose is given as 30 injections of 6.7 units each. The injections are given 1 cm apart into your bladder wall. This injection procedure is described further in the “How Botox is given” section above.

Botox treatment for urinary incontinence may be repeated when the drug’s effect wears off. But each treatment session must be at least 12 weeks apart.

Note: To learn more about urinary incontinence that’s caused by a nerve disorder, see the “Other uses for Botox” section above.

Dosage for upper and lower limb spasticity

The typical dosage of Botox for upper limb spasticity in adults ranges from 75 units to 400 units. For lower limb spasticity in adults, the typical dosage of Botox ranges from 300 units to 400 units. Dosages for limb spasticity in children are described below in the “Pediatric dosage” section.

The exact Botox dosage for this use depends on the size, location, and number of muscles affected. It also depends on the severity of your spasticity. The total recommended dosage for spasticity is divided into multiple injections into affected muscles.

Botox treatment for spasticity may be repeated when the drug’s effect wears off. But each treatment session must be at least 12 weeks apart.

The dosage you’re given for spasticity may change each time you have a session for Botox injections. Your dosage will vary depending on how your body responded to previous injections.

Note: To learn more about upper and lower limb spasticity, see the “Other uses for Botox” section above.

Dosage for cervical dystonia

The dosage of Botox for cervical dystonia depends on the severity of the condition, level of pain it’s causing, and muscles affected. The total recommended dosage of Botox for cervical dystonia is divided into multiple injections into the affected muscles.

In clinical studies, the average dose of Botox given for cervical dystonia was 236 units. Typically, treatment is started with a lower dose that may be increased depending on how your body responds to the drug.

Botox treatment for cervical dystonia may be repeated when the drug’s effect wears off. This time frame is typically 12 weeks after a treatment session.

Note: To learn more about cervical dystonia, see the “Other uses for Botox” section above.

Dosage for severe axillary hyperhidrosis

The recommended dosage of Botox for severe axillary hyperhidrosis is 50 units per armpit. This total recommend dose for each armpit is split into 10 to 15 injections. The injections are given 1 cm to 2 cm apart over each armpit.

Botox treatment for severe axillary hyperhidrosis may be repeated when the drug’s effect wears off. For this purpose, repeat Botox treatment is typically done at least 8 weeks after the first injection.

Note: To learn more about severe axillary hyperhidrosis, see the “Other uses for Botox” section above.

Dosage for blepharospasm

The recommended starting dosage of Botox for blepharospasm (uncontrollable blinking) is 1.25 units to 2.5 units. This total recommended dose is given as the following three injections into each affected eye:

  • two injections into the upper eyelid
  • one injection into the lower eyelid

Botox treatment for blepharospasm may be repeated when the drug’s effect wears off. This time frame is typically 12 weeks after a treatment session.

Your doctor may recommend a higher dose of Botox each time you receive a set of injections. But this depends on how your body responds to previous injections. However, doses that are higher than 5 units per injection site are unlikely to be more effective than lower doses.

Note: To learn more about blepharospasm, see the “Other uses for Botox” section above.

Dosage for strabismus

The recommended starting dosage of Botox for strabismus depends on which muscle is affected. But the typical starting dosage ranges between 1.25 units to 5 units. This total dose is given as one injection into each affected muscle.

Botox treatment for this condition may be repeated when the drug’s effect wears off. The time frame for this is typically 12 weeks after a treatment session. But for strabismus, a single Botox injection may correct the condition.

If you have repeat treatment, your doctor may recommend a higher dosage of Botox each time you receive Botox injections. But this depends on how your body responds to previous injections. The maximum recommended dosage of Botox for this use is 25 units into any one muscle.

Note: To learn more about strabismus, see the “Other uses for Botox” section above.

Pediatric dosage

Botox is approved for certain uses in children. Below, we list these uses and describe the typical recommended dosage for each of them.

Note: To learn more about the conditions listed below, see the “Other uses for Botox” section above.

Dosage for upper and lower limb spasticity

Botox is approved to treat upper and lower limb spasticity in children ages 2 years and older. The typical dosage for this use is based on the child’s body weight.

Botox dosage for spasticity depends on the size, location, and number of muscles affected. It also depends on the severity of the child’s spasticity. The total dosage calculated is divided into multiple injections, which are given into the affected muscles.

Botox treatment for spasticity may be repeated when the drug’s effect wears off. But each treatment session must be at least 12 weeks apart.

The dosage recommended by your child’s doctor may change each time Botox is given. Dosages will depend on how your child responds to previous injections.

Dosage for upper limb spasticity in children

The recommended dosage for upper limb spasticity ranges from 3 to 6 units per kilogram (kg) of body weight. The total dose given in one treatment session shouldn’t be higher than either 6 units of Botox per kg of body weight or 200 units, whichever amount is lower.

Dosage for lower limb spasticity in children

The recommended dosage for lower limb spasticity ranges from 4 to 8 units per kg of body weight. The total dose given in one treatment session shouldn’t be higher than 8 units per kg of body weight or 300 units, whichever amount is lower.

Dosage for limb spasticity affecting more than one limb in children

In some cases, both the right and left leg, or both the arms and legs, are treated with Botox. In these cases, the total Botox dosage in a 3-month period shouldn’t be greater than either 10 units per kg of body weight or 340 units, whichever amount is lower.

Dosage for blepharospasm

The recommended dosage of Botox for blepharospasm (uncontrollable blinking) in children is the same as that described above for adults. See the section above for details.

Dosage for strabismus

The recommended dosage of Botox for strabismus in children is the same as that described above for adults. See the section above for details.

What if I miss a dose?

If you miss an appointment for your Botox injections, call your doctor’s office to reschedule.

And to help make sure that you don’t miss an appointment for your injections, try setting a reminder on your phone. A note on your calendar may be helpful, too.

Will I need to use this drug long term?

Botox is meant to be used as a long-term treatment for most of its approved conditions. For these conditions, the drug may be given repeatedly as your doctor recommends. But for strabismus, a single Botox injection may correct the condition.

If you and your doctor determine that Botox is safe and effective for you, you’ll likely use the drug long term for most conditions.

Here are answers to some frequently asked questions about Botox.

Does Botox for migraine help to reduce wrinkles?

It may, depending on where the wrinkles are. But Botox for migraine isn’t approved for this use.

Botox, which is approved to manage migraine and other health conditions, is a different medication than Botox Cosmetic. Both medications contain the same drug. However, Botox Cosmetic is approved to reduce wrinkles.

For migraine treatment, Botox is injected into some of the same places on your forehead where Botox Cosmetic is injected. Like Botox Cosmetic injections, Botox injections can help reduce frown lines between your eyebrows. The injections can also reduce horizontal creases in your forehead.

However, Botox is unlikely to help reduce wrinkles around your eyes (called crow’s-feet lines) because it’s not injected into the areas that would help reduce these wrinkles.

If you have questions about Botox and Botox Cosmetic, see the section above called “What is Botox?” or talk with your doctor.

What will happen if I stop using Botox?

If you stop using Botox, the drug’s effects tend to wear off after about 12 weeks from your last injection. In some cases, this can lead to your condition coming back. With chronic migraine, the condition may even get worse than it was before treatment.

If you have questions about stopping Botox treatment, talk with your doctor. They can discuss with you how stopping treatment will affect your condition.

Is Botox a steroid?

No, Botox isn’t a steroid. Steroids (also called corticosteroids) are drugs that reduce inflammation in your body.

Instead, Botox is a neurotoxin. It works by stopping nerves from sending messages. Botox is made from a toxin that’s produced by Clostridium botulinum bacteria.

Is Botox safe for older people to use?

Yes, in general, Botox is safe for use in older people. In clinical studies, there weren’t any differences in the overall safety of the drug between older people and younger people.

However, in people who used Botox for overactive bladder (OAB),* certain side effects were more common in older people than in younger people. These side effects were urinary tract infections (UTIs) and trouble emptying the bladder.

If you have questions about the safety of using Botox given your age, talk with your doctor.

* To learn about OAB, see the “Other uses for Botox” section above.

Is Botox used to treat vestibular migraine?

Botox hasn’t been specifically studied for treating vestibular migraine. So it’s not known if Botox is an effective treatment for this condition.

With vestibular migraine, you have repeated attacks of dizziness or vertigo (spinning sensations). Your hearing and vision may also be affected. These attacks may be associated with other symptoms of migraine, such as nausea and headache. But they may also occur on their own.

Your doctor may prescribe Botox for vestibular migraines. But keep in mind that this is an off-label use. (With off-label use, a drug that’s approved for certain conditions is used for a different condition.)

If you’re interested in using Botox for vestibular migraine, talk with your doctor.They can recommend appropriate treatment options for your condition.

Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Botox, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Alternatives for chronic migraine

Examples of other drugs that may be used to prevent headaches from chronic migraine* include:

* For information about chronic migraine, see the “Botox for chronic migraine” section above.

Alternatives for urinary or bladder disorders

Examples of other drugs that may be used to treat urinary or bladder disorders* include:

* For information about urinary and bladder disorders that Botox is used to treat, see the “Other uses for Botox” section above.

Alternatives for upper and lower limb spasticity

Examples of other drugs that may be used to treat upper and lower limb spasticity* include:

* For information about upper and lower limb spasticity, see the “Other uses for Botox” section above.

Alternatives for cervical dystonia

Examples of other drugs that may be used to treat cervical dystonia* include:

  • diazepam (Valium)
  • topiramate (Topamax)
  • trihexyphenidyl
  • benztropine (Cogentin)
  • levodopa/carbidopa (Sinemet)
  • abobotulinumtoxinA (Dysport)
  • incobotulinumtoxinA (Xeomin)
  • rimabotulinumtoxinB (Myobloc)

* For information about cervical dystonia, see the “Other uses for Botox” section above.

Alternatives for severe axillary hyperhidrosis

Examples of other drugs that may be used to treat severe axillary hyperhidrosis* include:

  • oxybutynin (Ditropan XL)
  • benztropine (Cogentin)
  • propantheline
  • glycopyrronium (Qbrexza)

* For information about severe axillary hyperhidrosis, see the “Other uses for Botox” section above.

Alternatives for eye muscle problems, such as blepharospasm or strabismus

Examples of other drugs that may be used to treat eye muscle problems, such as blepharospasm (uncontrollable blinking) or strabismus (crossed eyes or misaligned eyes) include:

  • incobotulinumtoxinA (Xeomin)

* For information about blepharospasm and strabismus, see the “Other uses for Botox” section above.

You may wonder how Botox compares with other medications that are prescribed for similar uses. Here we look at how Botox and Aimovig are alike and different.

Ingredients

Botox contains the drug onabotulinumtoxinA, while Aimovig contains the drug erenumab-aooe. These drugs belong to different classes of medications. (A medication class describes a group of drugs that work in the same way.)

Uses

Botox is FDA-approved for the following uses:

  • prevent headaches in adults with chronic migraine
  • treat overactive bladder (OAB) in adults with urinary incontinence, urgency, and frequency
  • treat urinary incontinence that’s caused by a nerve disorder, such as multiple sclerosis (MS) or spinal cord injury, in adults
  • treat upper or lower limb spasticity (involuntary muscle contractions) in adults
  • treat upper or lower limb spasticity in children ages 2 years and older
  • treat cervical dystonia (involuntary muscle spasms in the neck) in adults
  • treat blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms); for this purpose, Botox can be used in adults and children ages 12 years and older
  • treat strabismus (crossed eyes or misaligned eyes) in adults and children ages 12 years and older
  • treat severe axillary hyperhidrosis (excessive underarm sweating) in adults

Botox is approved to treat each of these conditions in certain situations. To learn more about using Botox for these conditions, see the “Botox for chronic migraine” and “Other uses for Botox” sections above.

Aimovig, on the other hand, is only approved for preventing migraine in adults.

Drug forms and administration

Botox comes as a powder inside single-use vials. It’s mixed into a solution and given as an injection by healthcare providers.

For most of its uses, Botox is given by intramuscular injection (injection into a muscle). It’s injected into muscles in different areas of your body, depending on the condition being treated.

For OAB and urinary incontinence caused by a nerve disorder, Botox is injected into the detrusor muscle of the bladder. This injection is done using a thin tube called a cystoscope that’s inserted into your bladder.

And for excessive sweating, Botox is injected into the skin of your armpit.

Botox injections are typically given once every 12 weeks.

Aimovig is a solution that comes in two forms: a prefilled autoinjector pen and a prefilled syringe. It’s given by subcutaneous injection (Injection under the skin). You can give Aimovig injections to yourself at home. They’re administered once a month.

Side effects and risks

Botox and Aimovig can cause some similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Botox, with Aimovig, or with both drugs (when taken individually).

  • Can occur with Botox:
    • pain, tenderness, redness, swelling, bruising, bleeding, or infection at Botox injection sites
    • unwanted muscle weakness near Botox injection sites
    • nausea
    • fever
    • achy muscles
    • upper respiratory tract infections, such as the common cold
    • headache
    • neck pain
    • drooping eyelids
  • Can occur with Aimovig:
    • redness, itchy skin, and pain at Aimovig injection sites
    • constipation
    • muscle cramps
  • Can occur with both Botox and Aimovig:
    • muscle spasms

Serious side effects

These lists contain examples of serious side effects that can occur with Botox, with Aimovig, or with both drugs (when taken individually).

  • Can occur with Botox:
    • spread of toxin effects, which may lead to trouble breathing or swallowing that may be life threatening*
    • corneal ulceration (open sore on the clear covering over the front of the eye) that’s due to reduced blinking in people using Botox for blepharospasm
  • Can occur with Aimovig:
    • severe constipation that may need to be treated in hospital or require surgery
  • Can occur with both Botox and Aimovig:

* Botox has a boxed warning for spread of toxin effects. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Effectiveness

Botox and Aimovig have different FDA-approved uses, but they’re both used to prevent chronic migraine.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Botox and Aimovig to be effective in preventing chronic migraine.

Costs

You can view cost estimates for both Botox and Aimovig on GoodRx.com. But the actual price you’ll pay for either drug depends on your insurance plan and your location. It also depends on the cost of the visit to your healthcare provider to receive doses.

Botox and Aimovig are both brand-name drugs. There are currently no generic forms of either drug. Brand-name medications usually cost more than generics.

You may wonder how Botox compares with other medications that are prescribed for similar uses. Here we look at how Botox and Topamax are alike and different.

Ingredients

Botox contains the drug onabotulinumtoxinA, while Topamax contains the drug topiramate. These drugs belong to different classes of medications. (A medication class describes a group of drugs that work in the same way.)

Uses

Botox is FDA-approved for the following uses:

  • prevent headaches in adults with chronic migraine
  • treat overactive bladder (OAB) in adults with urinary incontinence, urgency, and frequency
  • treat urinary incontinence that’s caused by a nerve disorder, such as multiple sclerosis (MS) or spinal cord injury, in adults
  • treat upper or lower limb spasticity (involuntary muscle contractions) in adults
  • treat upper or lower limb spasticity in children ages 2 years and older
  • treat cervical dystonia (involuntary muscle spasms in the neck) in adults
  • treat blepharospasm (uncontrollable blinking) that’s related to dystonia (involuntary muscle spasms); for this purpose, Botox can be used in adults and children ages 12 years and older
  • treat strabismus (crossed eyes or misaligned eyes) in adults and children ages 12 years and older
  • treat severe axillary hyperhidrosis (excessive underarm sweating) in adults

Botox is approved to treat each of these conditions in certain situations. To learn more about using Botox for these conditions, see the “Botox for chronic migraine” and “Other uses for Botox” sections above.

Topamax, on the other hand, is approved to:

  • prevent migraine in adults and children ages 12 years and older
  • treat epilepsy (specifically, partial-onset or primary generalized tonic-clonic seizures) in adults and children ages 2 years and older; for this use, the drug is given as the only treatment
  • treat epilepsy (specifically, partial-onset seizures, primary generalized tonic-clonic seizures, or seizures associated with Lennox-Gastaut syndrome) in adults and children ages 2 years and older; for this use, the drug is given in combination with other treatments

Drug forms and administration

Botox comes as a powder inside single-use vials. It’s mixed into a solution and given as an injection by healthcare providers.

For most of its uses, Botox is given by intramuscular injection (injection into a muscle). It’s injected into muscles in different areas of your body, depending on the condition being treated.

For OAB and urinary incontinence caused by a nerve disorder, Botox is injected into the detrusor muscle of the bladder. This injection is done using a thin tube called a cystoscope that’s inserted into your bladder.

And for excessive sweating, Botox is injected into the skin of your armpit.

Botox injections are typically given once every 12 weeks.

Topamax, on the other hand, comes as tablets and capsules that are taken by mouth. It’s taken twice each day.

Side effects and risks

Botox and Topamax can cause some similar and some different side effects. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Botox, with Topamax, or with both drugs (when taken individually).

  • Can occur with Botox:
    • pain, tenderness, redness, swelling, bruising, bleeding, or infection at Botox injection sites
    • unwanted muscle weakness near Botox injection sites
    • fever
    • achy muscles
    • headache
    • neck pain
    • drooping eyelids
  • Can occur with Topamax:
    • pins and needles sensations in your body
    • loss of appetite
    • weight loss
    • diarrhea
    • problems with concentration, memory, or speech
    • changes in taste
    • dizziness
    • sleepiness
  • Can occur with both Botox and Topamax:
    • nausea
    • upper respiratory tract infections, such as the common cold

Serious side effects

These lists contain examples of serious side effects that can occur with Botox, with Topamax, or with both drugs (when taken individually).

  • Can occur with Botox:
    • spread of toxin effects, which may lead to trouble breathing or swallowing that may be life threatening*
    • corneal ulceration (open sore on the clear covering over the front of the eye) that’s due to reduced blinking in people using Botox for blepharospasm
  • Can occur with Topamax:
    • eye problems, such as vision changes or raised pressure in the eye
    • reduced sweating and increased body temperature
    • metabolic acidosis (increased level of acid in the blood)
    • high level of ammonia in the blood
    • fetal harm if taken during pregnancy
  • Can occur with both Botox and Topamax:

* Botox has a boxed warning for spread of toxin effects. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Effectiveness

Botox and Topamax have different FDA-approved uses, but they’re both used to prevent chronic migraine.

The use of Botox and Topamax in preventing migraine has been directly compared in a clinical study. In this study, the drugs were similarly effective in preventing migraine.

For example, at 12 weeks of treatment:

  • 79.2% of people who received Botox had an overall improvement in their migraine attacks
  • 70.8% of people who took Topamax had the same result

In addition, the average number of headache days per month dropped by:

  • 8.0 days in people who received Botox
  • 8.1 days in people who took Topamax

If you’re interested in taking one of these drugs to prevent chronic migraine, talk with your doctor about which drug is right for you.

Costs

You can view cost estimates for both Botox and Topamax on GoodRx.com. But the actual price you’ll pay for either drug depends on your insurance plan and your location. It also depends on the cost of the visit to your healthcare provider to receive doses of Botox.

Botox and Topamax are both brand-name drugs. There’s currently no generic form of Botox. However, a generic form of Topamax is available. Brand-name medications usually cost more than generics.

Botox isn’t known to interact with alcohol. Alcohol doesn’t affect how this drug works. However, drinking alcohol after having Botox injections could increase your risk of certain side effects. Examples of these side effects include:

  • headache
  • dizziness
  • tiredness
  • blurred vision

If you drink alcohol, talk with your doctor about how much is safe for you to drink while you’re using Botox.

Botox can interact with several other medications. Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Botox and other medications

Below are lists of medications that can interact with Botox. These lists don’t contain all the drugs that may interact with Botox.

Before taking Botox, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Botox and blood thinners

Botox injections can cause bruising or bleeding. But the injections are more likely to do this if you also take blood thinning drugs.

Examples of blood thinning drugs include:

  • anticoagulants, such as:
    • apixaban (Eliquis)
  • antiplatelets, such as:
    • dipyridamole (Persantine)

If you take a blood thinning drug, talk with your doctor about your risk of bruising or bleeding with Botox. Your doctor may recommend that you stop the blood thinner temporarily before you receive Botox injections.

Botox and anticholinergics

Anticholinergics are used to treat a variety of conditions, including urge urinary incontinence and movement disorders such as Parkinson’s disease.

Taking an anticholinergic drug while receiving Botox injections can increase your risk of certain side effects. These side effects include blurred vision, dry mouth, dry eyes, or trouble urinating.

Examples of anticholinergic drugs that can increase your risk of side effects with Botox include:

  • oxybutynin (Ditropan XL, Gelnique)
  • solifenacin (Vesicare)
  • tolterodine (Detrol)
  • fesoterodine (Toviaz)
  • trospium
  • darifencin (Enablex)
  • trihexyphenidyl
  • benztropine (Cogentin)
  • propantheline

If you take an anticholinergic drug, talk with your doctor before starting Botox. They can recommend whether you should continue taking the drug while you’re receiving Botox injections.

Botox and muscle relaxants

Botox can cause unwanted muscle weakness around the area of where the drug is injected. And taking a muscle relaxant medication before or after having a Botox injection can increase your risk of this side effect.

Examples of muscle relaxants include:

  • baclofen (Gablofen, Lioresal, Ozobax)
  • diazepam (Valium)
  • dantrolene sodium (Dantrium)

If you take a muscle relaxant, talk with your doctor. They can recommend whether you should continue taking it while you’re having Botox injections.

Keep in mind that certain muscle relaxants are sometimes given with anesthesia during surgical procedures. If you have any surgeries, be sure to tell your doctor if you’re using Botox.

Botox and certain antibiotics

Certain antibiotics can increase the risk of side effects such as unwanted muscle weakness from Botox.

Examples of these antibiotics include:

  • neomycin
  • amikacin
  • gentamicin
  • tobramycin

If you’ve recently had treatment with one of these antibiotics, be sure to tell your doctor before receiving Botox injections. Your doctor will recommend whether it’s safe for you to have Botox.

If you need treatment with one of these antibiotics, let your doctor know if you’re using Botox. Your doctor will advise whether the antibiotic is safe for you to take or if you should take a different antibiotic instead.

Botox and other botulinum toxin products

Botox contains the drug onabotulinumtoxinA. It’s made from a toxin that’s produced by Clostridium botulinum bacteria. If Botox is given at the same time as, or within a few months of, other botulinum toxin products, it can cause severe muscle weakness.

Examples of other botulinum toxin products include:

  • rimabotulinumtoxinB (Myobloc)
  • abobotulinumtoxinA (Dysport)
  • incobotulinumtoxinA (Xeomin)

If you’ve received any other botulinum toxin product, be sure to tell your doctor before receiving a Botox injection. Botox should not be given until the effects of the other product have worn off.

Botox and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Botox. However, you should still check with your doctor or pharmacist before using any of these products while taking Botox.

Botox and foods

There aren’t any foods that have been specifically reported to interact with Botox. If you have any questions about eating certain foods with Botox, talk with your doctor.

As with all medications, the cost of Botox can vary.

The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

It’s important to note that you’ll receive Botox injections from a healthcare provider. So there may be additional charges related to getting doses of the drug. To find out how much Botox treatment will likely cost, talk with your doctor or their office staff.

Your insurance company may require you to get prior authorization before approving coverage for Botox. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Botox, contact your insurance plan.

Financial and insurance assistance

If you need financial support to pay for Botox, or if you need help understanding your insurance coverage, help is available.

Allergan, the manufacturer of Botox, offers the Botox Savings Program, which may help lower the cost of your treatment. For more information and to find out if you’re eligible for support, call 800-44-BOTOX (800-442-6869) or visit the program website.

Generic version

Botox isn’t available in a generic form. A generic drug is an exact copy of the active drug in a brand-name medication. Generics tend to cost less than brand-name drugs.

This drug comes with several precautions.

FDA warning: Spread of toxin effects

This drug has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

In some cases, Botox’s effects may spread away from the site where it’s injected. This can cause a serious condition called botulism, which may lead to symptoms such as:

  • lack of energy
  • muscle weakness all over your body
  • drooping eyelids
  • double vision
  • loss of bladder control
  • hoarse voice
  • trouble speaking
  • trouble breathing
  • trouble swallowing

These symptoms can occur hours, days, or weeks after you’ve had a Botox injection. Be sure to tell your doctor if you develop any symptoms of botulism, even if it’s not right after a Botox injection was given.

It’s important to note that breathing and swallowing problems caused by Botox can sometimes be life threatening. The risk of these problems is higher in people who already have breathing or swallowing problems.

If you have trouble breathing, swallowing, or speaking after having a Botox injection, call your doctor right away. But if your symptoms feel life threatening, call 911 or your local emergency number.

Other precautions

Before taking Botox, talk with your doctor about your health history. Botox may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Infection at a planned injection site. You shouldn’t receive Botox injections if you have an infection at one of your planned injection sites. If you do have an infection, Botox injections should be postponed until the infection clears up. And talk with your doctor about whether the infection needs to be treated with medication.
  • Urinary tract infection (UTI). If you’re using Botox to treat urinary incontinence, you shouldn’t receive Botox injections if you currently have a UTI. Instead, Botox injections should be postponed until the UTI goes away. Talk with your doctor about whether the UTI should be treated with medication. And if you get frequent UTIs, talk with your doctor about whether Botox is right for you.
  • Trouble emptying your bladder. If you’re using Botox to treat urinary incontinence, you shouldn’t receive Botox injections if you can’t completely empty your bladder on your own. (If you use a catheter to empty your bladder, this precaution doesn’t apply to you.) If you have trouble emptying your bladder, talk with your doctor before receiving Botox.
  • Allergic reaction. If you’ve had an allergic reaction to Botox or any of its ingredients, you shouldn’t receive Botox injections. And you shouldn’t receive Botox injections if you’ve had an allergic reaction to any other botulinum toxin product. These products include rimabotulinumtoxinB (Myobloc), abobotulinumtoxinA (Dysport), or incobotulinumtoxinA (Xeomin). Ask your doctor other medications that are better options for you.
  • Neuromuscular disorders. With neuromuscular disorders, your nerves don’t communicate well with your muscles. Examples of these disorders include amyotrophic lateral sclerosis (ALS), myasthenia gravis (MG), and Lambert-Eaton syndrome. If you have one of these disorders, you could have an increased risk of certain side effects of Botox. These side effects include muscle weakness, double vision, and drooping eyelids. They also include trouble speaking, swallowing, or breathing. If you have a neuromuscular disorder, talk with your doctor about whether Botox is right for you. If you do receive Botox, your doctor will monitor you closely for these side effects.
  • Planned surgery. Certain medications that may be used with anesthesia during surgical procedures could increase the risk of side effects with Botox. If you have any planned surgeries, talk with your doctor about whether Botox is right for you to use around the time of your surgery.
  • Pregnancy. It’s not known if Botox is safe to use during pregnancy. For more information, please see the “Botox and pregnancy” section above.
  • Breastfeeding. It’s not known if Botox passes into breast milk or if it affects breast milk production. For more information, please see the “Botox and breastfeeding” section above.

Note: For more information about the potential negative effects of Botox, see the “Botox side effects” section above.

The following information is provided for clinicians and other healthcare professionals.

Indications

Botox has FDA-approval for:

  • prevention of headaches in adults with chronic migraine, which is defined as migraine occurring on at least 15 days per month, with a headache lasting at least 4 hours per day
  • treatment of overactive bladder (OAB) in adults with urge urinary incontinence, urgency, and frequency; for this use, Botox is indicated when anticholinergics are not effective or not tolerated
  • treatment of urinary incontinence that is caused by detrusor overactivity related to a neurologic condition, such as multiple sclerosis; for this use, Botox is indicated in adults when anticholinergics are not effective or not tolerated
  • treatment of upper and lower limb spasticity in adults; for this use, Botox is given to reduce severity of muscle contraction in elbows, wrists, fingers, thumbs, ankles, or toe flexors
  • treatment of upper and lower limb spasticity in children ages 2 years and older
  • treatment of cervical dystonia in adults
  • treatment of severe axillary hyperhidrosis that is not well managed with topical treatments in adults
  • treatment of blepharospasm that is related to dystonia in adults and children ages 12 years and older
  • treatment of strabismus in adults and children ages 12 years and older

Administration

Botox is administered by intramuscular injection for all approved indications except hyperhidrosis, OAB, and urinary incontinence caused by a neurological condition. For OAB and urinary incontinence caused by a neurological condition, Botox is administered by intradetrusor injection. And for hyperhidrosis, Botox is administered by intradermal injection.

Botox is not interchangeable with other botulinum toxin products.

Overdose

Botox overdose can lead to excessive neuromuscular weakness, either local to or distant from* the injection site. Symptoms may not appear for up to several weeks after the injection. If overdose is suspected, people who received the drug should be closely monitored throughout this time period, and in some cases, they may require hospitalization.

* Botox has a boxed warning for spread of toxin effects. The drug can affect the muscles of the oropharynx and esophagus, leading to aspiration, or it can affect the respiratory muscles, requiring respiratory support.

Mechanism of action

Botox contains onabotulinumtoxinA, which is a complex that contains botulinum toxin type A in addition to other proteins. Botulinum toxin is a neurotoxin that is produced by Clostridium botulinum bacteria.

Botox produces its effects by blocking transmission at neuromuscular junctions, autonomic ganglia, and postganglionic cholinergic nerve endings.

Botox binds irreversibly to receptors on presynaptic nerve terminals and is taken up into the nerve terminal. The toxin enters the cytoplasm, where it inactivates a protein called SNAP-25. This protein is essential for enabling vesicles to fuse with the cell membrane and release acetylcholine.

The blockage of acetylcholine release by Botox is irreversible, but the effect wears off as new nerve terminals sprout and form new synapses.

Pharmacokinetics and metabolism

Botox cannot be detected in blood after intramuscular injection.

Contraindications

Botox is contraindicated in people with:

  • hypersensitivity to Botox, any of its ingredients, or any other botulinum toxin product, such as rimabotulinumtoxinB (Myobloc), abobotulinumtoxinA (Dysport), or incobotulinumtoxinA (Xeomin)
  • infection at a planned injection site
  • urinary tract infection (UTI), if the person is using Botox for OAB or urinary incontinence
  • urinary retention or a post-void residual urine volume that is greater than 200 mL if the person is using Botox for OAB or urinary incontinence; however, this contraindication is not applicable to those using a catheter

Storage

Before opening, keep Botox powder in a refrigerator, at a storage temperature of 36°F to 46°F (2°C to 8°C). Once reconstituted, Botox can be stored in a refrigerator for up to 24 hours before use.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.