Mayzent (siponimod) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to treat relapsing forms of multiple sclerosis (MS) in adults.

With MS, your immune system attacks your brain and spinal cord. This can cause symptoms such as muscle weakness, numbness and tingling, and trouble walking.

If you and your doctor agree that Mayzent is working well to treat your MS symptoms, you’ll likely take the drug long term.

Here are some fast facts on Mayzent:

  • Active ingredient: siponimod
  • Drug class: sphingosine 1-phosphate receptor modulator
  • Drug form: oral tablets
  • FDA approval year: 2019

Like other drugs, Mayzent can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Mayzent, including details about its uses, see this article.

Mayzent can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days or weeks. But if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Mayzent in clinical trials:

  • headache
  • hypertension (high blood pressure)*
  • increase in blood levels of liver enzymes (certain proteins) called transaminases
  • falls
  • swelling in your hands, feet, joints, or face*

* For more information on this side effect, see “Side effect specifics” below.

Mild side effects can occur with Mayzent use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Mayzent’s medication guide.

Mild side effects that have been reported with Mayzent include:

These side effects may be temporary, lasting a few days or weeks. But if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Mayzent and want to tell the FDA about it, visit MedWatch.

* For more information on this side effect, see “Side effect specifics” below.

Mayzent may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Mayzent’s medication guide.

If you develop serious side effects while taking Mayzent, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects and their symptoms that have been reported include:

  • Liver injury. Symptoms can include:
    • nausea and vomiting
    • abdominal (belly) pain
    • jaundice (yellowing of your skin, the whites of your eyes, or both)
  • Infection, including sinus infection or bronchitis (a type of lung infection). Symptoms can include:
    • cough
    • fever
    • rash
    • shortness of breath
    • stuffy nose
  • Decreased lung function. Symptoms can include:
    • chest pain
    • trouble breathing
    • feeling tired
    • wheezing
  • Posterior reversible encephalopathy syndrome (swelling in your brain). Symptoms can include:
    • confusion
    • tiredness or fatigue
    • blindness
    • seizures
  • Skin cancers, including melanoma and basal cell carcinoma. Symptoms can include:
    • new moles or growths
    • existing moles or growths getting larger in size or changing significantly
    • skin lesions (unusual-looking areas of skin) that itch, bleed, or otherwise show changes from the surrounding skin
  • New or worsening multiple sclerosis (MS) symptoms when stopping Mayzent treatment. Symptoms can include:
    • vision changes
    • dizziness
    • numbness or tingling
  • Hypertension (high blood pressure).*
  • Ocular (eye-related) side effects, specifically macular edema (fluid buildup in your eye).*
  • Allergic reaction.*†

* For more information on this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after using Mayzent. But this side effect wasn’t reported in clinical studies.

Mayzent may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Do MS medications such as Mayzent cause weight gain?

No, weight gain wasn’t reported as a side effect by people taking Mayzent in clinical trials. But some other medications used to treat multiple sclerosis (MS), such as corticosteroids, can cause weight gain. Examples of corticosteroids include Rayos (prednisone) and DexPak (dexamethasone).

Keep in mind that MS itself can cause symptoms such as fatigue (lack of energy) and pain. This can make it hard for people with MS to exercise regularly.

If you have concerns about weight gain while taking Mayzent, talk with your doctor. They can suggest ways to maintain a weight that’s healthy for you.

What is Mayzent’s most common side effect?

Headache was Mayzent’s most common side effect in clinical trials. This is considered a mild side effect of the drug.

For a list of Mayzent’s common side effects, see the “More common side effects of Mayzent” section above. You can also talk with your doctor or pharmacist about Mayzent’s common side effects.

Do Mayzent’s side effects include hair loss?

No. Hair loss wasn’t reported as a side effect in clinical trials of Mayzent.

But hair loss can be a side effect of other drugs used to treat MS. These drugs include Trexall (methotrexate) and Rebif (interferon-beta-1a).

If you have concerns about hair loss or thinning hair while taking Mayzent or other drugs for MS, talk with your doctor or pharmacist. They may suggest treatments for this side effect.

Learn more about some of the side effects that Mayzent may cause.

Ocular (eye-related) side effects

Although rare, ocular (eye-related) side effects can occur while taking Mayzent. Specifically, macular edema was reported by people taking Mayzent in clinical trials.

Macular edema is a buildup of fluid in your eye. This can cause symptoms such as:

  • distorted vision
  • trouble with color vision, such as colors looking unusually faded
  • blurry vision

If macular edema isn’t treated, it can lead to permanent vision loss.

What you can do

Before you start taking Mayzent, your doctor will recommend that you have an eye exam. Your doctor may also recommend an eye exam if you notice any vision changes while taking Mayzent.

Having diabetes or uveitis (a type of eye inflammation) increases your risk for macular edema. Make sure your doctor is aware if you have either of these conditions before you take Mayzent.

If you notice symptoms of macular edema while taking Mayzent, contact your doctor right away. They’ll discuss the risks and benefits of continuing to take the medication, as well as other potential treatments for your multiple sclerosis (MS).

Swelling in your hands, feet, joints, or face

Swelling in your hands, feet, joints, or face can occur with Mayzent. This is called peripheral edema. But no one in the clinical trials of the drug reported serious swelling.

What you can do

If you notice swelling in your hands, feet, joints, or face while taking Mayzent, call your doctor.

This side effect typically goes away after a few days or weeks of taking the drug.

If you have swelling that’s bothersome or concerning, your doctor may suggest a treatment, such as a diuretic. This is a drug that gets rid of excess fluid in your body. If you have swelling that doesn’t go away, your doctor may suggest trying a different treatment for your MS.

High blood pressure

Hypertension (high blood pressure) was one of the more common side effects of Mayzent in clinical trials. Small increases in systolic blood pressure (the top number on a blood pressure reading) and diastolic blood pressure (the bottom number on a blood pressure reading) were both reported.

In clinical trials, these increases were first noticed about a month after people started Mayzent, and didn’t go away with time.

High blood pressure doesn’t cause symptoms in most people, especially the small increases that occurred in people taking Mayzent.

You’ll take your first dose of Mayzent in your doctor’s office or clinic. This allows your blood pressure and heart rate to be monitored for possible side effects, including high blood pressure. You’ll also have an electrocardiogram before your first dose of Mayzent, or soon after taking your first dose. This helps your doctor see how your heart will respond to Mayzent.

What you can do

Your doctor will likely have you monitor your blood pressure at home while you’re taking Mayzent. If your blood pressure increases while taking Mayzent, contact your doctor. They may prescribe medications to treat this side effect.

Allergic reaction

As with most drugs, Mayzent can cause an allergic reaction in some people. But this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • rash
  • itching
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Mayzent. But if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Mayzent. This drug may not be the right treatment for your condition if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Current infection. You shouldn’t take Mayzent if you have an infection that’s currently causing symptoms. This is because Mayzent works by weakening your immune system. This means your body may not be able to fight the infection as well as it usually would. Tell your doctor if you have an infection before you take Mayzent, so that your infection can be treated first.

Heart problems. If you have certain heart problems, your doctor will likely monitor you more closely than usual while taking Mayzent. These problems include heart block or a slow heart rate. Taking Mayzent can cause your heart rate to decrease. This could be dangerous if you already have heart problems.

Your doctor may consult with a cardiologist about whether Mayzent is safe for you to take if you have heart problems. A cardiologist may also recommend how your heart rate should be monitored during Mayzent treatment.

Liver problems. Mayzent can cause liver problems, including liver damage, as a side effect. If you already have a liver problem, such as hepatitis, it may get worse with Mayzent. Your doctor can help determine if Mayzent is safe for you to take if you have liver problems.

Lung problems. Mayzent can cause breathing problems, including a decrease in lung function. People who already have lung problems, such as asthma, may have even more trouble breathing if they take Mayzent. If you have lung problems, your doctor can help determine whether Mayzent is safe for you to take.

CYP2C9*3/*3 genotype. Before your doctor prescribes Mayzent, you’ll have genetic testing done. This is to make sure your body can get rid of Mayzent after you take a dose. Your body uses proteins called CYP enzymes to help metabolize (break down) drugs such as Mayzent. Specifically, the CYP2C9 enzyme helps to break down Mayzent.

If you have the CYP2C9*3/*3 genotype (a specific version of CYP2C9), your body won’t break down Mayzent as well as usual. This could cause too much of the drug to build up in your body, which increases your risk for side effects. Your doctor can recommend other treatments if you have the CYP2C9*3/*3 genotype.

Allergic reaction. You shouldn’t take Mayzent if you’ve ever had an allergic reaction to Mayzent or any of its ingredients. Talk with your doctor about which other treatments are better choices for you.

Alcohol use with Mayzent

There aren’t any known interactions between taking Mayzent and drinking alcohol. But both alcohol and Mayzent can cause liver problems. Combining the two may increase your risk for this type of side effect.

If you drink alcohol, ask your doctor how much, if any, alcohol is safe for you to have while you’re taking Mayzent.

Pregnancy and breastfeeding while taking Mayzent

It’s not known whether it’s safe to take Mayzent while pregnant or breastfeeding. In fact, you’ll need to use an effective form of birth control while taking Mayzent, and for at least 10 days after your last dose.

Talk with your doctor if you’re pregnant or breastfeeding (or planning to become pregnant or breastfeed) before you take Mayzent.

Like most drugs, Mayzent can cause some mild side effects, including some that are common. Most mild side effects of the drug go away as you continue to take the drug, without requiring medical attention.

There are also some possible serious side effects of Mayzent. You should talk with your doctor if you experience symptoms of serious side effects, including:

You should also talk with your doctor if you become pregnant while taking Mayzent. It’s not known if it’s safe to use the drug while pregnant.

If you’d like to learn more about Mayzent, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

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.