Velsipity (etrasimod) is a prescription oral tablet used to treat moderate to severe ulcerative colitis in adults. Velsipity can cause side effects that range from mild to serious. Examples include headache and dizziness.

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

Mild side effects have been reported with Velsipity. 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 Velsipity unless your doctor recommends it.

Velsipity 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.
† An allergic reaction is possible after taking Velsipity, but this side effect wasn’t reported in studies.

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

  • temporarily slowed heart rate after starting treatment
  • serious infection*
  • increased risk of skin cancer*
  • high blood pressure
  • high cholesterol
  • liver problems
  • decreased lung function
  • macular edema (swelling in the back of the eye)
  • posterior reversible encephalopathy syndrome (PRES), a rare but life threatening condition caused by sudden swelling in the blood vessels of the brain
  • severe allergic reaction*†

If you develop serious side effects while taking Velsipity, 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.
† An allergic reaction is possible after taking Velsipity, but this side effect wasn’t reported in studies.

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 Velsipity, visit MedWatch.

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


Velsipity lowers your white blood cell count, so it can raise your risk of getting an infection. (White blood cells help your body fight infections.) Infections were a common side effect reported in studies of Velsipity.

The most common infections reported with Velsipity were urinary tract infections (UTIs) and herpes virus infections, such as cold sores, genital herpes, chickenpox, and shingles. These infections are usually mild.

Symptoms of infection can include:

  • fever
  • flu-like symptoms
  • pain or burning sensation when urinating
  • skin rash or sores
  • burning or tingling sensation in the affected area

Symptoms of brain infections can include:

  • headache with fever
  • neck stiffness
  • sensitivity to light
  • worsening weakness or numbness
  • clumsiness or difficulty with balance
  • confusion
  • changes in vision

Factors that can increase the risk of infection during your Velsipity treatment include having a weak immune system and not being up to date with recommended vaccines.

You may have a weak immune system if you take medications that affect your immune system. These include certain cancer drugs, as well as immunosuppressant and immunomodulator medications.

You may also have an increased risk of infection for 4–5 weeks after stopping Velsipity treatment. It can take this long for your white blood cells to return to normal levels.

What might help

Before starting Velsipity, tell your doctor about any medications you currently take. Also tell them if you have any current infections or infections that keep coming back. You should also talk with your doctor about your vaccination history.

Before prescribing Velsipity, your doctor will likely check your white blood cell count to make sure Velsipity is safe for you. They may also prescribe medication to treat any infections you have to avoid these getting worse. If needed, they may recommend getting certain vaccines before starting treatment.

If you have symptoms of infections while taking Velsipity or in the 5 weeks after stopping Velsipity, see your doctor right away. You may need medication to treat the infection. If you have a serious infection, your doctor will usually have you stop taking Velsipity until the infection goes away.

If you have questions or concerns about your risk of infection with Velsipity, talk with your doctor.

Increased risk of skin cancer

Velsipity may increase your risk of skin cancer. Skin cancer wasn’t reported in studies of Velsipity. But this side effect has been reported with other medications from the same group of drugs as Velsipity.

Symptoms of skin cancer can include:

  • change in the size or color of a mole
  • new mole, wart, or skin growth
  • rough or scaly patch with raised edges
  • skin sore that bleeds or crusts and doesn’t heal
  • shiny, smooth bump that’s red or dark

Factors that can raise the risk of skin cancer when taking this drug include exposure to sunlight or UV light. Other factors include taking medication that weakens your immune system, such as immunosuppressant medication or certain cancer drugs.

What might help

While taking Velsipity, you should limit the amount of time you spend in the sun. When outside, protect your skin with a high SPF sunscreen or clothing, including a hat. And avoid using sunlamps or tanning beds.

You should frequently check your skin for any changes while taking Velsipity. If you notice any changes, see your doctor as soon as possible.

If you have questions or concerns about your risk of skin cancer with Velsipity, talk with your doctor.

Allergic reaction

Like most drugs, Velsipity can cause an allergic reaction in some people. This side effect wasn’t reported in studies, but it could still occur.

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 Velsipity, 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 Velsipity, they may have you switch to a different treatment.

Keeping track of side effects

During your Velsipity 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 Velsipity affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Velsipity.


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

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

Alcohol and Velsipity

There are no known interactions between alcohol and Velsipity. But alcohol and Velsipity can cause some similar side effects, including headache and dizziness. So you may be more likely to have these side effects if you drink alcohol during your Velsipity treatment.

Velsipity can also cause increased liver enzymes, which could be worsened by excessive alcohol use.

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

Pregnancy and breastfeeding with Velsipity

Velsipity is usually prescribed for someone who’s pregnant or breastfeeding only if the benefits of treatment outweigh the potential risks to the fetus or child.


It’s not known whether it’s safe to take Velsipity during pregnancy. But this drug may cause harm to a fetus. If you’re pregnant or planning to become pregnant, talk with your doctor about your treatment options.

If you’re able to become pregnant, your doctor may recommend using a form of birth control during your Velsipity treatment and for 1 week after your last dose.

If you become pregnant during your Velsipity treatment, consider signing up for the pregnancy registry for this drug by calling 800-616-3791. A pregnancy registry collects information about the safety of certain drugs when used during pregnancy.


It isn’t known whether Velsipity is safe to take while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before starting Velsipity treatment.

Like most drugs, Velsipity can cause a number of side effects that range from mild to serious. However, most are temporary and go away after a few days to weeks. If you have questions about side effects that Velsipity can cause, talk with your doctor.

Examples of questions to help get you started include:

  • How often do serious side effects occur with Velsipity?
  • Do my other health conditions or medications raise my risk of side effects from Velsipity?
  • Do other medications that could treat my condition have similar side effects to Velsipity?

To learn more about Velsipity, see this article.

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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.