Vumerity (diroximel fumarate) is a prescription drug that’s used to treat certain forms of multiple sclerosis. Vumerity can cause side effects that range from mild to serious. Examples include flushing and diarrhea.

Specifically, Vumerity is used in adults to treat the following relapsing forms of multiple sclerosis (MS):

Vumerity is also prescribed to treat clinically isolated syndrome (CIS) in adults. This is a condition that may develop into MS.

The active ingredient in Vumerity is diroximel fumarate. An active ingredient is what makes a drug work. Vumerity comes as a delayed-release capsule. This is a type of capsule that resists stomach acid so it can release the drug in your intestines instead.

Keep reading to learn about the common, mild, and serious side effects Vumerity can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Vumerity treatment. Examples of the drug’s commonly reported side effects include:

* To learn more about this side effect, see the “Side effects explained” section below.

Mild side effects have been reported with Vumerity. These include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Vumerity unless your doctor recommends it.

Vumerity may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.

Serious side effects have been reported with Vumerity. These include:

If you develop serious side effects while taking Vumerity, 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.

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Vumerity, visit MedWatch.

Get answers to some frequently asked questions about Vumerity’s side effects.

How do the side effects of Vumerity compare with those of Tecfidera or Ocrevus?

Vumerity, Tecfidera, and Ocrevus are prescribed to treat certain relapsing forms of multiple sclerosis (MS).

Vumerity and Tecfidera are expected to cause the same side effects. The active ingredient* in Vumerity is diroximel fumarate; the active ingredient in Tecfidera is dimethyl fumarate.

After you take a dose of Vumerity or Tecfidera, your body turns diroximel fumarate or dimethyl fumarate into monomethyl fumarate (MMF). So whether you take Vumerity or Tecfidera, your body ultimately changes either drug into MMF, which is what works to treat MS.

As for Ocrevus, it causes similar side effects as Vumerity and Tecfidera, but some different ones as well. For example, mild respiratory infections (such as the common cold) occurred frequently in studies of Ocrevus, but weren’t reported with Vumerity or Tecfidera.

Talk with your doctor or pharmacist to learn more about how drugs for treating MS compare to one another.

* An active ingredient is what makes a drug work.

Is weight gain a possible side effect of Vumerity?

No, it’s not thought so. Weight gain isn’t a side effect reported in studies of Vumerity.

Corticosteroids, such as prednisone, are commonly prescribed to treat MS. Corticosteroids are known to cause weight gain.

According to the National Multiple Sclerosis Society, it’s not unusual for people with MS to experience weight gain due to symptoms of the condition. For example, fatigue (low energy) and depression can make it harder to engage in physical activity.

Talk with your doctor if you have concerns about your weight, or would like to know whether medications you take could cause weight gain.

Does Vumerity cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. It also includes side effects that may not go away, even after you stop taking the drug.

Examples of long-term side effects reported in Vumerity’s studies include:

Talk with your doctor to learn more about possible side effects of Vumerity and how long they may last.

Learn more about some of the side effects Vumerity may cause.


Flushing was the most common side effect reported in studies of Vumerity. Flushing may cause temporary symptoms such as:

  • warmth
  • skin redness or discoloration
  • an itching or burning sensation (anywhere in the body)

According to the drug’s studies, flushing is most likely to occur when you first start taking Vumerity. It typically goes away on its own as you continue treatment.

What might help

If you have flushing during Vumerity treatment, consider the following options to help relieve your symptoms:

  • take your Vumerity doses with food
  • if your doctor says it’s safe for you to do so, take one dose of regular aspirin (up to 325 mg) about 30 minutes before your Vumerity doses

If you experience flushing that is bothersome or doesn’t go away, tell your doctor. They may recommend stopping treatment with Vumerity and exploring other MS treatments instead.

Liver damage

In studies of Vumerity, liver damage was rare. Symptoms include:

If you have an existing liver condition, taking Vumerity could worsen it. You may also have an increased risk of new liver problems.

What might help

Your doctor will likely order blood tests to check your liver enzyme levels before prescribing Vumerity for you. If these results show a high level, your doctor may decide to prescribe a different MS treatment for you.

During treatment, your doctor will continue to order these tests to check your liver health. You should let them know right away if you think you’re having symptoms of liver damage.

Allergic reaction

Like most drugs, Vumerity can cause an allergic reaction in some people, but these reactions were rare in studies. Symptoms can be mild to serious and can include:

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

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Vumerity, they’ll decide whether you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Vumerity, they may have you switch to a different treatment.

Keeping track of side effects

During your Vumerity treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Vumerity affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Vumerity.


Vumerity can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Vumerity is a good treatment option for you.

Talk with your doctor about your health history before starting Vumerity. Be sure to tell them if any of the following factors apply to you:

Alcohol and Vumerity

You should not drink alcohol at the same time that you take a dose of Vumerity.

In addition, alcohol may worsen certain side effects of Vumerity. These include flushing and diarrhea. And for some people, drinking alcohol can worsen symptoms of multiple sclerosis (MS). Vumerity is prescribed to treat certain forms of MS.

If you have questions about consuming alcohol during Vumerity treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Vumerity

There is limited information about the safety of Vumerity treatment during pregnancy or while breastfeeding.


It’s not known whether it’s safe to take Vumerity during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before starting this drug.


It’s not known whether Vumerity is safe to take while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Like most drugs, Vumerity can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects Vumerity can cause, talk with your doctor. Examples of questions to help get you started include:

  • Are side effects of Vumerity similar to other medications that could treat my form of multiple sclerosis (MS)?
  • If I take other MS medications along with Vumerity, can these drugs interact and increase my risk of side effects?
  • Are there certain foods to eat with my Vumerity dose to lower the risk of flushing?
  • Should I let you know if I make changes to my diet or other lifestyle changes while taking Vumerity?

To learn more about Vumerity, see these articles:

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Disclaimer: Healthline 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 another 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.