Cialis is a brand-name prescription medication. It’s FDA-approved to treat the following in men:

Cialis comes as a tablet that you swallow. It’s available in four strengths: 2.5 mg, 5 mg, 10 mg, 20 mg. Depending on your situation and what condition Cialis is treating, you’ll take the drug either before sexual activity or once a day.

Cialis contains the active drug ingredient tadalafil and belongs to a group of medications called phosphodiesterase 5 (PDE5) inhibitors. For ED, Cialis relaxes the blood vessels leading to the penis so that more blood can flow into it. For BPH symptoms, Cialis relaxes muscles in your bladder, allowing you to urinate more easily.

Cialis is available only by prescription. It’s not available over the counter.

Effectiveness

For information on the effectiveness of Cialis in treating these conditions, please see the “Cialis uses” section below.

Cialis is available as a generic drug called tadalafil. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. Generics tend to cost less than brand-name drugs.

In some cases, the brand-name drug and the generic version may come in different forms and strengths.

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

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

Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

If you have certain conditions, such as kidney or liver problems, your doctor may have you start with a low dose of Cialis. This is done so that the medication doesn’t affect your other conditions.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths: 2.5 mg, 5 mg, 10 mg, 20 mg

Cialis comes as a tablet that you swallow. It’s available in four strengths: 2.5 mg, 5 mg, 10 mg, and 20 mg.

Dosage for benign prostatic hyperplasia (BPH)

For symptoms of benign prostatic hyperplasia, the recommended dosage of Cialis is 5 mg once a day. You should take the drug at about the same time each day.

In some cases, your doctor may have you take 5 mg of Cialis a day along with finasteride (Proscar) to treat BPH. (See the “Cialis use with other drugs” section below to learn more.) If you take both Cialis and finasteride, you’ll usually take these two drugs for up to 26 weeks.

Dosage for erectile dysfunction (ED)

Here’s some information on the Cialis dosages for erectile dysfunction.

Cialis taken as needed

If your doctor recommends that you take Cialis only as needed for ED, the usual dosage is 10 mg before sexual activity. They may reduce this to 5 mg if the medication is working too well. But if this dose doesn’t work for you, your doctor may have you take two 5 mg tablets of Cialis at once. This will increase the dose back to 10 mg.

If the 10-mg dose of Cialis isn’t working well enough, your doctor may increase it to 20 mg. The maximum dose of Cialis that can be taken in a day is 20 mg.

You shouldn’t take Cialis more than once a day. In clinical trials, Cialis helped people with ED symptoms for up to 36 hours after their dose. So if you’re taking the medication only as needed, you shouldn’t have to take it every day.

Note: It’s very important that you take only the amount of Cialis that your doctor instructs you to take. And be sure to speak with them if you feel you need more of the drug, rather than increasing your dosage yourself.

Cialis taken once a day

Cialis can also be taken once a day to treat ED. In this case, the dosage usually starts at 2.5 mg a day. If this daily dosage doesn’t work well enough to treat your ED, your doctor may increase it to 5 mg a day.

And if your doctor recommends using Cialis every day, you should take the drug at about the same time each day. You don’t need to take Cialis before sexual activity unless your doctor says to use the drug only as needed. (See the “Cialis taken as needed” section right above to learn more.)

Note: It’s very important that you take only the amount of Cialis that your doctor instructs you to take. And be sure to speak with them if you feel you need more of the drug, rather than increasing your dosage yourself.

Dosage for ED and BPH

To treat both ED and symptoms of BPH together, the typical dose of Cialis is 5 mg, once a day. You should try to take your dose at about the same time each day.

Higher dosages of Cialis

The approved dosages of Cialis for ED, BPH symptoms, or both, are between 2.5 mg and 20 mg a day or as needed. Dosages higher than 20 mg a day haven’t been studied, and it’s not known what side effects may occur with them.

For example, if you take your “as-needed” dose of 20 mg twice a day, you’ll end up taking 40 mg. This dose is too high and may cause serious side effects, such as decreased blood pressure.

Note: It’s very important that you take only the amount of Cialis that your doctor instructs you to take. And be sure to speak with them if you feel you need more of the drug, rather than increasing your dosage yourself.

What if I miss a dose?

If you forget to take your once-a-day dose of Cialis, take it as soon as you remember. However, never take two doses in 1 day. If you missed your dose yesterday, just skip the missed dose and continue with your once-a-day dosing.

To help make sure that you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Will I need to use this drug long term?

If you’re using Cialis to treat BPH, this medication may be a long-term treatment. Cialis may also be used to treat ED long term.

But in some cases, your doctor may determine the cause of your ED, such as depression or an illness. In such instances, you may be able to stop taking Cialis after the cause of your ED has been treated.

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

For more information on the possible side effects of Cialis, 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 Cialis, you can do so through MedWatch.

Mild side effects

Mild side effects of Cialis can include:*

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 Cialis. To learn about other mild side effects, talk with your doctor or pharmacist, or see Cialis’s Patient Package Insert.

Serious side effects

Serious side effects from Cialis 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:

  • Changes in hearing. Symptoms can include:
    • trouble hearing
    • ringing in your ears
    • dizziness

Other serious side effects, explained in more detail below in “Side effect details,” include:

Side effect details

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

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Cialis. Allergic reactions did occur in clinical trials of Cialis, but it wasn’t reported how many people had them. The allergic reactions included a serious rash and skin conditions such as Stevens-Johnson syndrome (a life threatening rash that causes painful blisters).

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing

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 Cialis. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Headache

Headache is a common side effect that may occur with Cialis. In clinical trials, depending on the condition being treated:

  • between 3% and 15% of people who took Cialis had headaches
  • between 2.3% and 5% of people who took a placebo (treatment with no active drug) had headaches

If you have headaches that are bothersome to you while using Cialis, talk with your doctor. They may be able to recommend ways to help ease this side effect.

Changes in blood pressure

Changes in blood pressure are a possible side effect of taking Cialis. Low blood pressure occurs most often while taking this medication. But high blood pressure can occur as well.

Low blood pressure

Clinical trials looked at blood pressure in people who took 20 mg of Cialis or a placebo. Blood pressure decreased by an average of 1.6/0.8 mm Hg more in the Cialis group than in the placebo group.

A decrease in blood pressure may be more likely if you’re taking Cialis along with other medications that can also lower blood pressure.

Symptoms of low blood pressure can include:

If you have these symptoms while taking Cialis, tell your doctor right away. They’ll help determine what’s causing the low blood pressure and the best way to treat it.

High blood pressure

Although rare, Cialis may also increase your blood pressure. This was a side effect that was reported only in people who took Cialis once a day for erectile dysfunction (ED). In this trial, depending on the condition being treated:

  • between 1% and 3% of people who took the medication had high blood pressure
  • no one who took a placebo had high blood pressure

If you have any symptoms of high blood pressure, such as headaches or chest pain, tell your doctor right away. They’ll help determine what’s causing the increase in blood pressure and the best way to treat it.

Back pain

Back pain is a common side effect with Cialis. In clinical trials, depending on the condition being treated, back pain was reported in:

  • 2% to 6% of people who took Cialis
  • 1% to 3% of people who took a placebo

Back pain usually occurs between 12 and 24 hours after taking Cialis. Usually, back pain goes away within 2 days of taking your dose.

While taking Cialis, if you have back pain that’s bothersome to you or doesn’t go away, talk with your doctor. They may be able to recommend ways to help ease this side effect. Your doctor may also do more testing to see what’s causing your back pain.

Heartburn

Heartburn is a common side effect of Cialis. In clinical trials, depending on the condition being treated, heartburn occurred in:

  • 1% to 10% of people who took Cialis
  • 0.2% to 2% of people who took a placebo

If you have heartburn that’s bothersome to you while taking Cialis, talk with your doctor. They may be able to recommend ways to treat this side effect.

Prolonged erection

It’s possible to get a prolonged erection that lasts more than 4 hours while taking Cialis. It wasn’t reported how many people had a prolonged erection in clinical trials.

This side effect can lead to priapism, which is a painful erection lasting longer than 4 hours. It’s considered an emergency because it can cause permanent damage to your penis, such as being unable to have erections at all.

If you have an erection that lasts longer than 4 hours while using Cialis, see a doctor or go to the hospital right away. The prolonged erection should be treated as soon as possible so that it doesn’t cause lasting damage.

Loss of vision

Very rarely, Cialis may cause a loss of vision in either one eye or both eyes. It’s not known how many people had a loss of vision in clinical trials. Also, it’s not known if Cialis was the cause of vision loss or if other factors play a role.

While taking Cialis, if you have any changes in vision, such as decreased vision or loss of vision, tell your doctor right away. They’ll help determine what’s causing the vision change and how to best treat it.

How to avoid Cialis side effects

The best way to take Cialis is to use it exactly as your doctor directs, either once a day at the same time each day or only as needed. You shouldn’t take any other medications to treat erectile dysfunction (ED) while you’re using Cialis, unless your doctor says that it’s OK. And you should never take Cialis more than once a day.

It’s also important to avoid drinking too much alcohol while you’re using Cialis. (See the “Cialis and alcohol” section below to learn more.)

In addition, be sure to talk with your doctor or pharmacist about any other medications that you’re taking. They’ll be able to determine if the drugs may interact with Cialis and if that may lead to an increased risk of side effects. If you have any questions about the best way to avoid specific side effects from Cialis, talk with your doctor.

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

Ingredients

The active drug ingredient in Cialis is tadalafil. The active drug ingredient in Viagra is sildenafil. Both Cialis and Viagra belong to a group of medications called phosphodiesterase 5 (PDE5) inhibitors.

Uses

The Food and Drug Administration (FDA) has approved Cialis and Viagra to treat erectile dysfunction (ED) in men. ED is a condition in which you can’t get or keep an erection.

Cialis is also FDA-approved to treat the following in men:

Drug forms and administration

Both Cialis and Viagra come as tablets that you swallow. Cialis may be taken once a day or just when needed for sexual activity. Usually, Viagra is taken only as needed for sexual activity.

Side effects and risks

Cialis and Viagra both contain medications to treat ED. Therefore, these medications can cause very 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 Cialis, with Viagra, or with both drugs (when taken individually).

  • Can occur with Cialis:
    • pain in your arms or legs
  • Can occur with Viagra:
    • abnormal vision
    • nausea
    • dizziness
    • rash
  • Can occur with both Cialis and Viagra:
    • flushing (warmth and redness in your skin)
    • muscle pain

Serious side effects

This list contains examples of serious side effects that can occur with Cialis and Viagra when taken individually.

  • prolonged erection (an erection that lasts more than 4 hours)
  • loss of vision
  • changes in hearing, such as trouble hearing or ringing in your ears
  • allergic reaction
  • changes in blood pressure

Effectiveness

Cialis and Viagra have different FDA-approved uses, but they’re both used to treat ED.

The use of Cialis and Viagra in treating ED has been directly compared in clinical studies.

One study’s results

One study compared men who took Cialis either once a day or as needed with men who took Viagra as needed.

  • The study showed that men in the Cialis group had more improvement in their confidence than those in the Viagra group.
  • The Cialis group was also less concerned about how long their erection lasted than the Viagra group. This is because Cialis works longer than Viagra.

Results from a second study

In another ED study, men took either Cialis as needed or Viagra as needed for 4 weeks. They then switched to the other medication for an additional 4 weeks. Finally, the men decided which drug they preferred.

Researchers found that 69.1% of men preferred Cialis and 30.9% of men preferred Viagra. Most often, men reported that they preferred Cialis because the medication lasts longer in the body.

The study also looked at how well the drugs worked to treat ED. This was determined by a portion of a survey the men took called the International Index of Erectile Function (IIEF). A higher score on the IIEF meant that erectile function was better, so ED symptoms improved. Scores for self-esteem and relationship quality were about equal in the two groups.

IIEF scores improved by:

  • an average of 12.03 points for men who originally took Cialis
  • about 11.86 points for men who originally took Viagra

Costs

Cialis and Viagra are both brand-name drugs. Currently, there are generic forms of both drugs. The generic form of Cialis is called tadalafil. The generic form of Viagra is called sildenafil. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, the costs of Cialis and Viagra will vary depending on your treatment plan. The generic versions of both Cialis and Viagra cost significantly less than the brand-name versions. The actual price you’ll pay for any of these drugs depends on your insurance plan, your location, and the pharmacy you use.

Like Viagra (above), the drug Levitra has uses similar to those of Cialis. Here’s a comparison of how Cialis and Levitra are alike and different.

Ingredients

The active drug ingredient in Cialis is tadalafil. The active drug ingredient in Levitra is vardenafil. Both Cialis and Levitra belong to a group of medications called phosphodiesterase 5 (PDE5) inhibitors.

Uses

The Food and Drug Administration (FDA) has approved Cialis and Levitra to treat erectile dysfunction (ED) in men. ED is a condition in which you can’t get or keep an erection.

Cialis is also FDA-approved to treat the following in men:

Drug forms and administration

Both Cialis and Levitra come as tablets that you swallow. Cialis can be taken once a day or as needed for sexual activity. Levitra is taken only as needed for sexual activity.

Side effects and risks

Cialis and Levitra both contain medications used to treat ED. Therefore, these medications can cause very 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 Cialis, with Levitra, or with each drug (when taken individually).

Serious side effects

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

  • Can occur with Cialis:
    • no unique serious side effects
  • Can occur with Levitra:
  • Can occur with both Cialis and Levitra:
    • prolonged erection (an erection that lasts more than 4 hours)
    • loss of vision
    • changes in hearing, such as trouble hearing or ringing in your ears

Effectiveness

Cialis and Levitra have different FDA-approved uses, but they’re both used to treat ED.

The use of Cialis and Levitra in treating ED has been directly compared in a clinical study, but the results weren’t released.

Studies have found both Cialis and Levitra to be effective for treating ED.

Costs

Cialis and Levitra are both brand-name drugs. Currently, there are generic forms of both drugs. The generic form of Cialis is called tadalafil. The generic form of Levitra is called vardenafil. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, the costs of Cialis and Levitra will vary depending on your treatment plan. The generic versions of both Cialis and Levitra cost significantly less than the brand-name versions. The actual price you’ll pay for any of these drugs depends on your insurance plan, your location, and the pharmacy you use.

Here’s a look at how the drugs Cialis and Adcirca compare.

Uses

Both Cialis and Adcirca have the same active drug ingredient, tadalafil. However, the Food and Drug Administration (FDA) has approved the drugs to treat different conditions.

Cialis is FDA-approved to treat the following in men:

Adcirca is approved to treat a type of high blood pressure in your lungs called pulmonary arterial hypertension (PAH). The drug is for use in men and women. PAH is a specific kind of pulmonary hypertension that occurs in the arteries of your lungs.

Although these medications are very similar, they can’t be swapped. This means that if you’re taking Cialis for ED or symptoms of BPH, you shouldn’t take Adcirca instead. And if you’re taking Adcirca for PAH, you shouldn’t take Cialis instead.

Drug forms and administration

Although the active drug ingredient is the same in both Cialis and Adcirca, the two drugs have different dosages. If you’re taking Cialis, your dosage may be 2.5 mg to 20 mg as needed before sexual activity or once a day. But if you’re taking Adcirca, your dosage is usually 40 mg a day.

You should take Cialis according to your doctor’s or healthcare provider’s instructions.

Cialis comes as a tablet that you swallow.

When to take

Your doctor may want you to take Cialis once a day or just as needed for sexual activity. If you have questions about how often you can take Cialis if you’re using it as needed, talk with your doctor. Keep in mind that you should never take Cialis more than once a day.

The best time to take Cialis depends on whether you’re taking it once a day or only as needed. If you’re using the medication once a day, be sure to take it at about the same time each day.

If you’re taking Cialis only as needed, you may wonder how long before having sex you should take it. The best time to take an “as-needed” dose is about 2 hours before sex. This is because on average, it takes the drug 2 hours to be at the highest level in your body. So at about 2 hours, you’ll have the best effects from the medication. However, some people may have better erectile function 30 minutes after they take the drug.

To help make sure that you don’t miss a once-a-day dose, try setting a reminder on your phone. A medication timer may be useful, too.

Taking Cialis with food

You can take Cialis with or without food.

Can Cialis be crushed, split, or chewed?

You shouldn’t crush, split, or chew Cialis. Swallow the tablet whole. It’s not known if the medication will be as safe and effective if you crush, split, or chew it.

Here are answers to some frequently asked questions about Cialis.

Can women take Cialis?

No. Cialis isn’t approved for use in women. However, there are other options to treat women with a low sex drive.

Bremelanotide (Vyleesi) is an injectable medication that works on an area of your brain to improve sexual desire. This drug is also known as PT-141. Another medication used to treat low sex drive in women is the pill flibanserin (Addyi).

If you have questions about treating low sex drive in women, talk with your doctor.

Does Cialis work and is it safe?

Yes, the Food and Drug Administration (FDA) has approved Cialis. And before the FDA approves a medication, it must test the drug for safety and effectiveness. Clinical trials show that Cialis is a safe and effective drug to treat erectile dysfunction (ED), benign prostatic hyperplasia (BPH), or both.

However, for some people, Cialis may not be a safe option. This can include people with heart conditions such as an irregular heart rhythm and people who take other medications such as nitrates. (See the “Cialis precautions” section below to learn more.)

Before you start using Cialis, be sure to tell your doctor about any medical conditions you have and any medications you’re taking. They’ll be able to decide if Cialis is a safe choice for you. And talk with your doctor if you have any concerns.

Will Cialis help me keep an erection after ejaculating?

No. After ejaculation, you’ll likely lose your erection even if you’re taking Cialis.

After ejaculation occurs, your sexual excitement usually decreases. This means that you’ll likely lose your erection after ejaculation. And whether or not you’re using Cialis, you still need sexual stimulation to have an erection.

However, Cialis can still work up to 36 hours after you take your dose. So the drug may help you get another erection.

How long does Cialis stay in your system?

Cialis can stay in your system for more than 2 days after your dose. If you’re using the medication as needed, the drug may still increase your ability to get and maintain an erection 2 days after your last dose.

Can Cialis be used to treat ED after prostate surgery?

Yes, Cialis can be used to treat ED after prostate surgery.

A clinical trial was done in people with ED who had surgery to have their prostate removed. The people used either Cialis or a placebo (treatment with no active drug) as needed. After 4 weeks, the people took a portion of a survey called the Index of Erectile Function (IIEF). A higher score on the IIEF meant that erectile function was better, so ED symptoms improved.

The study showed that:

  • people who took Cialis after prostate surgery had an increase in their scores of about 5.3 points
  • people who took a placebo after prostate surgery had an increase of about 1.1 points

If you have questions about using Cialis to treat ED after prostate surgery, talk with your doctor.

Does Cialis increase the size of a man’s penis?

No. Cialis doesn’t increase the size of a man’s penis. However, the medication does increase blood flow to the area. So if the penis wasn’t able to become fully erect before taking Cialis, it may appear larger after taking Cialis.

Although Cialis doesn’t change the size of the penis, the drug can increase the ability to have an erection.

Cialis is approved to treat erectile dysfunction (ED), symptoms of benign prostatic hyperplasia (BPH), or both of these conditions.

Erectile dysfunction explained

ED is a condition in which a man may be unable to get or maintain an erection. An erection occurs when blood flows into the penis and remains there for a period of time. This happens because the blood vessels and muscles in the penis relax and open up, allowing more blood to flow into the area.

Cyclic guanosine monophosphate (GMP) is a chemical in your body that relaxes the muscles in the penis and increases blood flow into the penis. With ED, this activity isn’t working properly, so you can’t have or maintain an erection.

What Cialis does for ED

Cialis belongs to a group of medications called phosphodiesterase 5 (PDE5) inhibitors. It works to treat ED by blocking PDE5. When PDE5 is blocked, your body makes more cyclic GMP. And when you have more cyclic GMP, the blood vessels and muscles in your penis relax. This allows more blood to flow in and produce an erection.

Benign prostatic hyperplasia explained

BPH is a condition in which the prostate gland gets larger but isn’t cancerous. BPH may cause problems with urination such as the need to urinate frequently or having to urinate more often at night.

What Cialis does for BPH symptoms

Cialis is approved to treat the symptoms of BPH, but it’s not known exactly how the drug does this. It’s believed that Cialis works by relaxing muscles in your bladder, which allows you to urinate more easily.

How long does it take for Cialis to work?

Cialis works fairly quickly to treat your ED, BPH symptoms, or both conditions. Studies show that the medication may work as quickly as 30 minutes after you take your dose. However, in some people, the medication may take up to 6 hours until you notice it working.

On average, it takes about 2 hours for Cialis to peak. This is how long it takes for you to have the highest level of medication in your body. This is when the drug should work the best to treat your ED, symptoms of BPH, or both conditions.

Cialis can work for up to 36 hours in your body.

To treat erectile dysfunction (ED), your doctor may have you take Cialis only as needed before sexual activity. (See the “Cialis dosage” section above to learn more.) In this case, Cialis may keep working for up to 36 hours in helping you have and maintain erections during that time.

However, if you take Cialis each day for either benign prostatic hyperplasia (BPH) or ED, you’ll always have medication in your system. Therefore, it will continue to work throughout the day.

The Food and Drug Administration (FDA) approves prescription drugs such as Cialis to treat certain conditions. Cialis 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.

Cialis for benign prostatic hyperplasia (BPH)

Cialis is approved by the FDA to treat the symptoms of benign prostatic hyperplasia.

BPH is a condition that occurs in men as they age. It happens when the prostate gland slowly increases in size but isn’t cancerous. As the prostate gland gets bigger, it begins to push on your bladder. So eventually you may experience symptoms of BPH, including:

  • needing to urinate often, especially at night
  • straining to urinate
  • producing a weak stream of urine
  • being unable to urinate
  • feeling that your bladder didn’t empty after urinating

Effectiveness

Cialis was an effective medication to treat symptoms of BPH in clinical trials.

Researchers used a scale called the International Prostate Symptom Score (IPSS). IPSS is a questionnaire that was given to people to determine if their BPH symptoms improved. The symptoms included urinary urgency (sudden need to urinate), weak urine stream, and straining to urinate.

A higher score meant that symptoms of BPH were worse. The goal was to have a lower score, which indicates that people have had fewer and less severe symptoms of BPH.

The studies looked at people with BPH who took Cialis or a placebo (treatment with no active drug). Researchers found that people who took:

  • Cialis had a decrease in their IPSS score of 4.8 to 5.6 points
  • a placebo had a decrease in their IPSS score of 2.2 to 3.6 points

This means that the Cialis group noticed a larger decrease in the number and severity of BPH symptoms than the placebo group.

Cialis for erectile dysfunction (ED)

Cialis is FDA-approved to treat erectile dysfunction.

ED is a condition in which a man may have trouble having or maintaining an erection so they can have sex. There are many different causes of ED, including:

Sometimes ED can be helped by simply addressing the cause, such as treating an illness or anxiety. In other cases, you may need medication such as Cialis to treat your ED.

Effectiveness

Cialis was shown in clinical trials to be an effective medication to treat ED. The drug was studied using part of a survey called the Index of Erectile Function (IIEF). A higher score on the IIEF meant that erectile function was better, so ED symptoms improved. The people in the study took the survey after 4 weeks.

One trial looked at people who took 20 mg of Cialis or a placebo only when needed to treat their ED.

  • People who took Cialis had their IIEF scores improve by 6.9 to 9.3 points. This means that their ED symptoms eased while they were taking Cialis.
  • People who took a placebo either lost points or improved by a maximum of only 0.3 points. Losing points on the scale means that their ED symptoms worsened.

In another trial, people took 2.5 mg or 5 mg of Cialis, or a placebo on an everyday basis to treat their ED.

  • The study showed that for people who took any strength of Cialis, their IIEF scores improved by 6.1 to 9.7 points. This means that their ED symptoms eased while they were taking Cialis.
  • In comparison, people who took a placebo had improvements of only 0.9 to 1.2 points.

Cialis for ED and BPH

Cialis is FDA-approved to treat both ED and the symptoms of BPH together. These are two different conditions and aren’t usually caused by the same issues. For details on ED and BPH, see the “Cialis for benign prostatic hyperplasia (BPH)” and “Cialis for erectile dysfunction (ED)” sections above.

In some cases, medications for BPH, such as dutasteride (Avodart), may cause a lower libido (sex drive) and result in ED. However, ED and BPH are common in aging males, and aren’t necessarily related.

Effectiveness

Cialis was an effective medication in clinical trials for people with both ED and BPH. The studies used two different questionnaires, one for ED symptoms and one for BPH symptoms, to determine how well the medication worked.

Measuring results for BPH symptoms

To measure improvement of BPH, researchers used a scale called the International Prostate Symptom Score (IPSS). IPSS is a questionnaire that was given to people to determine if their BPH symptoms improved. The symptoms included urinary urgency (sudden need to urinate), weak urine stream, and straining to urinate.

A higher score meant that symptoms of BPH were worse. The goal was to have a lower score, which indicates that people have had fewer and less severe symptoms of BPH.

Researchers found the following:

  • People with both ED and BPH who took Cialis had a decrease in their IPSS scores of 6.1 points.
  • In comparison, people who took a placebo had a decrease in their score of about 3.8 points.

This means that, on average, people who took Cialis noticed a larger decrease in their BPH symptoms than people who took a placebo.

Measuring results for ED

To measure the improvement of ED symptoms, researchers used part of a survey called the Index of Erectile Function (IIEF). People with both ED and BPH took the survey after 4 weeks. A higher score on the IIEF meant that erectile function was better, so ED symptoms improved.

Researchers found the following:

  • People who took Cialis had an increase in their IIEF scores of about 6.5 points.
  • In comparison, people who took a placebo had an increase of only 1.9 points.

This means that people who took Cialis usually had greater erectile function than people who took a placebo.

Off-label use for Cialis

In addition to the uses listed above, Cialis may be used off-label for other purposes. Off-label drug use is when a drug that’s approved for one use is used for a different one that’s not approved. Below is an example of an off-label use for Cialis.

Cialis for ureteral stones

Cialis isn’t FDA-approved to treat ureteral stones. However, it may be used off-label for this purpose. A clinical trial compared Cialis with tamsulosin (Flomax), a drug that’s often used to treat ureteral stones. The study showed that more people who took Cialis were able to pass their stones than people who took tamsulosin.

Ureteral stones usually start out as kidney stones and then move into the ureter (the tube that urine travels in from the kidney to the bladder). Kidney stones are minerals that form a stone inside a kidney.

Cialis may work to treat ureteral stones by relaxing the ureter muscles. This makes the ureter wider, which can help you pass the stones more easily.

If you have questions about taking Cialis for ureteral stones, talk with your doctor.

Both alcohol and Cialis can decrease your blood pressure. So if you drink alcohol while taking this medication, it’s recommended that you don’t drink too much. This may help prevent your blood pressure from becoming too low.

Having five or more drinks (five shots or glasses of wine or beer) along with Cialis can increase the risk of side effects. In addition to decreased blood pressure, these side effects can include:

If you drink alcohol, talk with your doctor about what amount is safe to drink while you’re taking Cialis.

Other drugs are available that can treat your erectile dysfunction (ED), symptoms of benign prostatic hyperplasia (BPH), or both. Some medications may be a better fit for you than others. If you’re interested in finding an alternative to Cialis, talk with your doctor. They can tell you about other drugs 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 benign prostatic hyperplasia (BPH)

Examples of other drugs that may be used to treat symptoms of BPH include:

  • alfuzosin (Uroxatral)
  • doxazosin (Cardura)
  • silodosin (Rapaflo)
  • tamsulosin (Flomax)
  • dutasteride (Avodart)
  • finasteride (Proscar)

Alternatives for erectile dysfunction (ED)

Examples of other drugs that may be used to treat ED include:

Alternatives for ED and BPH

Cialis is the only medication that the Food and Drug Administration (FDA) has approved to treat both ED and symptoms of BPH together. However, other combinations of drugs may be used for this purpose. Also, other single medications may be used off-label to treat both ED and symptoms of BPH together.

Examples of other drugs that may be used to treat ED and symptoms of BPH together include:

  • sildenafil (Viagra)
  • vardenafil (Levitra)
  • finasteride (Proscar) and sildenafil
  • finasteride and vardenafil

Using more than the recommended dosage of Cialis can lead to serious side effects.

Don’t use more Cialis than your doctor recommends.

Overdose symptoms

Doses of up to 500 mg of Cialis have been tested. Doses of up to 100 mg have also been given to people once a day. Overdose symptoms were similar to the normal side effects people have had after taking Cialis. (For more about side effects, see the “Cialis side effects” section above.)

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.

If you’re taking Cialis, you usually won’t have to use other medications with it.

But if you have a prostate condition called benign prostatic hyperplasia (BPH), your doctor may first prescribe a drug called finasteride (Proscar).

Finasteride is a first-line treatment (the first treatment used) when medications are recommended for BPH. This is because the drug shrinks the prostate by blocking the growth of prostate cells. Cialis treats the symptoms of BPH by reducing the prostate gland muscle tone, but it doesn’t block the growth of the cells.

Finasteride can help also ease symptoms of BPH, such as having to urinate suddenly and more often. However, this medication can cause negative sexual side effects such as decreased libido (sex drive) and erectile dysfunction. To help ease these side effects, your doctor may have you also take Cialis.

If you have questions about using Cialis and finasteride, talk with your doctor.

What can I take to enhance Cialis?

You shouldn’t take anything in addition to Cialis to enhance the drug, unless your doctor tells you to.

When you get Cialis from the pharmacy, the pharmacist will add an expiration date to the label on the package or bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk with your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

You should store Cialis tablets at 77°F (25°C). But you can keep them between 59°F and 86°F (15°C and 30°C) for short periods of time, if needed. Store Cialis in a tightly sealed container away from light. And avoid keeping this medication in areas where it could get damp or wet, such as bathrooms.

Disposal

If you no longer need to take Cialis and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

Cialis can interact with several other medications. It can also interact with certain foods.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase the number of side effects or make them more severe.

Cialis and other medications

Below is a list of medications that can interact with Cialis. This list doesn’t contain all drugs that may interact with Cialis.

Before taking Cialis, 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.

Cialis and nitrates

You shouldn’t take Cialis if you’re taking a medication called a nitrate. This type of drug may be used for chest pain. Taking nitrates along with Cialis can cause a serious decrease in your blood pressure.

Examples of nitrates include:

  • nitroglycerin
  • isosorbide mononitrate (Monoket)
  • isosorbide dinitrate (Isordil)

However, in some cases, you doctor may give you a nitrate: for example, if you have chest pain and your life is at risk, and it’s been at least 48 hours since your last dose of Cialis. After you receive the nitrate, your doctor will likely monitor you to make sure your blood pressure doesn’t drop to an unsafe level.

Cialis and alpha-blockers

Both Cialis and medications called alpha-blockers can cause a decrease in blood pressure. So taking these medications together can cause blood pressure to drop further.

If you have benign prostatic hyperplasia (BPH) and are taking a medication called an alpha-blocker, you shouldn’t use Cialis.

And if you have erectile dysfunction (ED) and are taking an alpha-blocker, your doctor will likely lower your dose of Cialis.

Examples of alpha-blocker drugs include:

  • tamsulosin (Flomax)
  • alfuzosin (Uroxatral)
  • doxazosin (Cardura)

Before taking Cialis, tell your doctor about any medications that you use, including alpha-blockers.

Cialis and medications that lower blood pressure

Cialis may reduce your blood pressure. So if you’re taking other medications to reduce your blood pressure, using Cialis along with them may cause a larger drop in blood pressure.

Examples of blood pressure medications include:

Before you start Cialis treatment, tell your doctor if you’re taking any blood pressure drugs. They may give you a lower dose of Cialis or monitor you more often.

Cialis and medications to treat heartburn

If you’re taking Cialis and use antacids to treat heartburn, the antacids may decrease the level of Cialis that your body absorbs. This means that you may not get the full dose of Cialis, so it may not work as well to treat your ED or symptoms of BPH.

Examples of antacids include:

  • calcium carbonate (Tums)
  • aluminum hydroxide/magnesium hydroxide (Mylanta)

Before you start using Cialis, tell your doctor if you’re taking antacids. Talk with them about how far apart to take the doses of each drug if you need to use both medications.

Cialis and CYP3A4 inhibitors

Cialis is broken down in your body by an enzyme in your liver called CYP3A4. (An enzyme is a protein that aids chemical changes in your body.) Certain drugs can inhibit (block) this enzyme from working. So if the enzyme is unable to break down Cialis, the level of Cialis in your body may get too high. This can be dangerous and may increase your risk of side effects from Cialis. (For more about side effects, see the “Cialis side effects” section above.)

Examples of medications that can block CYP3A4 from working include:

Before starting Cialis treatment, talk with your doctor about any medications that you’re taking. They’ll be able to determine if the drugs are CYP3A4 inhibitors and if they can interact with Cialis. In some cases, your doctor may recommend a lower dose of Cialis or a different medication to treat your ED, symptoms of BPH, or both.

Cialis and CYP3A4 inducers

Cialis is broken down in your liver by an enzyme called CYP3A4. Certain drugs may induce (increase the activity of) CYP3A4, making it work better or faster than usual. This means that your body may break down Cialis more quickly than it should, so the drug may not affect you.

Examples of drugs that induce CYP3A4 include:

  • rifampin (Rifadin)
  • carbamazepine (Tegretol)
  • phenytoin (Dilantin)
  • phenobarbital

Before you start to use Cialis, talk with your doctor about any medications that you’re taking. They’ll be able to determine if the drugs are CYP3A4 inducers and if they can interact with Cialis. In some cases, your doctor may recommend a different medication to treat your ED, symptoms of BPH, or both.

Cialis and guanylate cyclase stimulators

You shouldn’t take Cialis if you’re using a type of drug called a guanylate cyclase stimulator. This kind of medication is used to treat people with pulmonary hypertension (a type of high blood pressure in your lungs). Using a guanylate cyclase stimulator along with Cialis may cause your blood pressure to become dangerously low.

An example of a guanylate cyclase stimulator is riociguat (Adempas). This medication can be used to treat pulmonary hypertension (PH) that happens in your arteries of your lungs (pulmonary arterial hypertension) or PH that happens due to a blood clot in your lungs.

Before taking Cialis, talk with your doctor about any medications you’re using for pulmonary hypertension. If you’re taking riociguat, they’ll likely recommend a different medication to treat your ED, BPH symptoms, or both.

Cialis and herbs and supplements

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

Cialis and foods

Here’s some information about how Cialis may interact with alcohol and grapefruit.

Alcohol

Both alcohol and Cialis can decrease your blood pressure. So if you drink alcohol while taking this medication, it’s recommended that you don’t drink too much. This may help prevent your blood pressure from becoming too low. For more information, see the “Cialis and alcohol” section above.

Grapefruit

While you take Cialis, it’s best to avoid eating grapefruit and drinking grapefruit juice.

Cialis is broken down in your body by an enzyme in your liver called CYP3A4. Grapefruit blocks that enzyme from working. So if the enzyme is unable to break down Cialis, the level of Cialis in your body may get too high. This can be dangerous and may increase your risk of side effects from Cialis. (For more about side effects, see the “Cialis side effects” section above.)

As with all medications, the cost of Cialis can vary. To find current prices for Cialis in your area, check out GoodRx.com.

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Before approving coverage for Cialis, your insurance company may require you to get prior authorization. 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 request and let you and your doctor know if your plan will cover Cialis.

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

Financial and insurance assistance

If you need financial support to pay for Cialis, or if you need help understanding your insurance coverage, reach out to your insurance company. They can aid you and tell you if there are any financial assistance options available.

Generic version

Cialis is available in a generic form called tadalafil. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs. To find out how the cost of tadalafil compares with the cost of Cialis, visit GoodRx.com.

If your doctor has prescribed Cialis and you’re interested in using tadalafil instead, talk with your doctor. They may have a preference for one version or the other. You’ll also need to check your insurance plan, as it may only cover one or the other.

Cialis isn’t approved for use in women. And there’s no information on Cialis use in pregnant women, so it’s not known if this medication is safe or effective for them.

Animal studies showed no problems with development of the fetus when the mother was given Cialis while pregnant. But animal studies don’t always predict what will happen in humans.

If you have questions about Cialis use during pregnancy, talk with your doctor.

Cialis isn’t approved for use in women. And it’s not known if the drug is safe to take 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 Cialis.

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

Cialis isn’t approved for use in women. And it’s not known if Cialis passes into breast milk or if it can be harmful to a breastfed child.

In animal studies, Cialis was present in breast milk. But animal studies don’t always predict what will happen in humans.

If you have questions about Cialis and breastfeeding, talk with your doctor.

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

  • Heart problems. Sexual activity has an impact on your heart function. So if you have a history of heart problems, talk with your doctor before taking Cialis. These heart problems can include a heart attack or an irregular heart rhythm. Your doctor will be able to tell you if your heart is healthy enough for you to have sex. And if you have symptoms such as chest pain or an irregular heartbeat while taking Cialis, you should stop any sexual activity and see a doctor as soon as possible.
  • Pulmonary hypertension. If you have pulmonary hypertension (a type of high blood pressure in your lungs), talk with your doctor before taking Cialis. In some cases, you may be taking a medication called riociguat (Adempas) to treat your pulmonary hypertension. And using this medication along with Cialis may cause your blood pressure to become dangerously low. You shouldn’t take Cialis if you’re taking riociguat for pulmonary hypertension.
  • Blood pressure problems. Cialis can cause both high blood pressure and low blood pressure. So if you already have either of these conditions, Cialis may make it worse. And you may be at a higher risk for symptoms from changes in blood pressure. (To learn more, see “Changes in blood pressure” in the “Side effect details” section above.) If you have a history of blood pressure problems, tell your doctor before you take Cialis. During your treatment, they may have you monitor your blood pressure more often to make sure it doesn’t become too high or too low.
  • Stroke. Cialis may increase your risk for stroke, especially if you have a history of stroke. In studies conducted after Cialis was approved, some people with a history of heart problems had strokes. If you have a history of stroke, be sure to talk with your doctor before taking Cialis. They’ll be able to determine if the medication is safe for you.
  • Liver problems. If you have a history of liver problems, such as hepatitis or liver failure, your body may not break down Cialis quickly enough. This means that the drug can build up in your system, which may increase your risk of side effects from the medication. (To learn more, see the “Cialis side effects” section above.) If you have liver problems, be sure to talk with your doctor before taking Cialis. They may have you start with a low dose.
  • Kidney problems. If you have kidney problems, such as chronic kidney disease, your body may not be able to get rid of Cialis as quickly as it should. This means that the medication may build up in your body, which can cause serious side effects. (To learn more, see the “Cialis side effects” section above.) If you have kidney problems, tell your doctor before you take Cialis. They may have you start with a low dose of the medication.
  • Severe vision loss. If you have any history of vision loss, talk with your doctor before taking Cialis. This vision loss may include having vision conditions such as non-arteritic anterior ischemic optic neuropathy (NAION). Using Cialis when you have vision loss may increase your risk for developing vision side effects. (See “Loss of vision” in the “Side effect details” section to learn more.) Your doctor may recommend a different medication than Cialis.
  • Retinitis pigmentosa. If you have retinitis pigmentosa (a genetic eye condition that may cause vision loss), you shouldn’t use Cialis. Taking Cialis when you have vision loss may increase your risk for developing vision side effects. (See “Loss of vision” in the “Side effect details” section to learn more.) Your doctor may recommend a different medication than Cialis.
  • Stomach ulcers. It’s possible that Cialis may increase your risk for bleeding. So if you have a history of stomach ulcers, taking Cialis may increase your risk of developing bleeding ulcers. (Stomach ulcers are sores in the lining of your stomach or intestine, and they may bleed.) Talk with your doctor before taking Cialis if you have a history of stomach ulcers. They may recommend a different treatment.
  • Bleeding problems. Cialis may increase your risk for bleeding. If you have a history of bleeding problems, such as hemophilia, taking Cialis may further increase your risk for bleeding. Talk with your doctor before taking Cialis if you have a history of bleeding problems. They may recommend a different treatment.
  • Deformed penis or Peyronie’s disease. If you have a deformed penis or a history of Peyronie’s disease (a curved penis), tell your doctor before taking Cialis. You may be at an increased risk for developing a long-lasting erection if you take the drug. Blood may become trapped in the penis and lead to an erection lasting longer than 4 hours, which can be dangerous and cause lasting damage. Your doctor will probably have you take a low dose of Cialis or use the medication with caution.
  • History of erections lasting longer than 4 hours. If you have a history of prolonged erections or priapism, you may be at an increased risk for developing them while taking Cialis. A prolonged erection is one that lasts more than 4 hours. And priapism is a painful erection that lasts more than 6 hours. Both conditions are considered emergencies and need to be treated right away to prevent long-term damage. So if you’ve had prolonged erections or priapism in the past, tell your doctor before you take Cialis. They may have you carefully monitor your condition after using Cialis.
  • Blood cell problems. Blood cell problems can includesickle cell anemia and blood cancers such as multiple myeloma or leukemia. If you have a blood cell problem, tell your doctor before using Cialis. You may be at an increased risk for developing a long-lasting erection when taking the drug. Erections lasting longer than 4 hours can be dangerous and may cause permanent damage. Your doctor may recommend a low dose of Cialis if you have blood cell problems.
  • Allergic reaction. If you’ve had an allergic reaction to Cialis or any of its ingredients, you shouldn’t take Cialis. Ask your doctor what other medications are better options for you.
  • Pregnancy. Cialis isn’t approved for use in women. And it’s not known if the medication is safe to take during pregnancy. For more information, please see the “Cialis and pregnancy” section above.
  • Breastfeeding. Cialis isn’t approved for use in women. And it’s not known if this medication is safe to take while breastfeeding. For more information, please see the “Cialis and breastfeeding” section above.

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

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

Indications

Cialis is indicated for the treatment of erectile dysfunction (ED) and the signs and symptoms of benign prostatic hyperplasia (BPH). It is also approved to treat men with both ED and BPH.

Administration

Cialis is a tablet that is taken orally. It is taken either once daily or only as needed.

Mechanism of action

Cialis is a phosphodiesterase 5 (PDE5) inhibitor. For ED, it works by blocking PDE5, which then increases cyclic guanosine monophosphate (GMP). The increase in cyclic GMP causes relaxation of smooth muscles and arteries, leading to more blood flowing into the penis.

It is not known exactly how Cialis works to treat symptoms of BPH. However, it is believed to work by relaxing smooth muscles around the prostate and bladder, leading to decreased urinary symptoms.

Pharmacokinetics and metabolism

After Cialis is dosed, the maximum concentration (Cmax) occurs between 30 minutes and 6 hours post-dose. The average Cmax occurs at 2 hours post-dose. Steady state is achieved after 5 days of once-daily dosing.

Volume of distribution of Cialis is about 63 L. It is highly protein-bound at about 94%.

Cialis is metabolized in the liver via CYP3A4 at first. It is then methylated and glucuronidated into its metabolized product, methylcatechol glucuronide.

Cialis is then excreted, 61% being present in the feces and 36% in the urine.

The half-life of Cialis is about 17.5 hours.

Contraindications

Cialis is contraindicated in:

  • patients taking nitrates
  • patients with a history of an allergic reaction to Cialis or tadalafil (Adcirca)
  • patients taking guanylate cyclase stimulators, such as riociguat (Adempas)

Storage

Cialis should be stored at 77°F (25°C), but brief deviations are permitted between 59°F and 86°F (15°C and 30°C).

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.