Xeljanz (tofacitinib) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to treat the following conditions in adults:

Xeljanz can be used if you’ve tried other drugs for your condition that either didn’t work well enough or caused bothersome side effects.

Xeljanz is also approved to treat polyarticular course juvenile idiopathic arthritis in children ages 2 years and older.

Here are some fast facts on Xeljanz:

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

These are just a few of the more common side effects reported by people who took Xeljanz in clinical studies. These side effects can vary depending on which condition the drug is being used to treat.

More common side effects in people taking Xeljanz for rheumatoid arthritis, psoriatic arthritis, and polyarticular course juvenile idiopathic arthritis include:

More common side effects in people taking Xeljanz for ulcerative colitis include:

* For more information about this side effect, see “Side effect Specifics” below.

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

Mild side effects that have been reported with Xeljanz 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 and reviews side effects of the medication. If you develop a side effect while taking Xeljanz and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect Specifics” below.

Xeljanz 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 the Xeljanz medication guide.

If you develop serious side effects while taking Xeljanz, 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* that have been reported include:

* For more information about each of these side effects, see “Side effect specifics” below.
Xeljanz has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.

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

Are hair growth and hair loss possible Xeljanz side effects?

No, Xeljanz isn’t known to cause hair loss or hair growth. Neither were reported in clinical trials of the drug.

According to a review of some small clinical trials, Xeljanz’s active drug (tofacitinib) might be an effective treatment for hair loss that’s caused by alopecia areata (an autoimmune disease). But more studies are needed to confirm this. At this time Xeljanz is not approved to treat hair loss.

If you have questions or concerns about hair loss or growth while taking Xeljanz, talk with your doctor.

Is depression a side effect of Xeljanz?

No, depression isn’t a side effect of Xeljanz. It wasn’t reported by people taking Xeljanz in clinical trials.

Keep in mind that it’s not uncommon for depression to occur in people who have the conditions that Xeljanz is approved to treat, such as psoriatic arthritis (PsA). In fact, some studies suggest that treating PsA may also improve depression in people who have both of these conditions.

If you have questions about depression or how taking Xeljanz might affect your mood, talk with your doctor.

Should I expect weight gain during my Xeljanz treatment?

No, weight gain isn’t an expected side effect of Xeljanz.

In fact, some of the possible serious side effects of Xeljanz (such as serious infections or diarrhea) can lead to unexplained weight loss.

If you have questions or concerns about your weight while taking Xeljanz, talk with your doctor. They can recommend ways for you to maintain a weight that’s healthy for you.

Can using Xeljanz affect my eyes?

No, using Xeljanz shouldn’t affect your eyes. People taking Xeljanz in clinical trials didn’t report side effects related to their eyes.

It’s important to note that if you have hepatitis B or hepatitis C, Xeljanz can cause the virus to become active again. This can cause symptoms of a hepatitis infection, such as jaundice. Jaundice can cause yellowing of your skin and/or the whites of your eyes.

For this reason, your doctor may test you for hepatitis B or C before or during your Xeljanz treatment. And if you develop symptoms of a hepatitis B or C infection, including eye side effects such as jaundice, let your doctor know as soon as possible.

Will I experience any side effects if I stop using Xeljanz?

There aren’t any specific side effects that are caused by stopping this drug. However, stopping treatment with Xeljanz could cause symptoms of your condition to return.

You should not stop taking Xeljanz without speaking with your doctor first about the risks and benefits of stopping treatment. If you and your doctor determine that stopping Xeljanz treatment is best for you, your doctor will likely recommend other treatments for your condition. This may help prevent your symptoms from returning after you stop Xeljanz.

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

Tears in the digestive tract

Although rare, Xeljanz may cause tears in your digestive tract. The digestive tract refers to your stomach and your small and large intestines.

Symptoms of this side effect can include stomach pain and fever. Changes in your bowel movements, such as diarrhea or constipation, can also be a symptom.

If you take any of the following medications together with Xeljanz, you may be at higher risk for tears in your digestive tract:

And if you currently have or have had either of the following conditions, you may also be at higher risk:

What you can do

Although digestive tract tears are rare, they can be serious. Be sure to contact your doctor right away if you have a fever, stomach pain that doesn’t go away, or any changes in your bowel habits.

Blood disorders

Taking Xeljanz can cause certain blood disorders. These include anemia (low levels of red blood cells) and leukopenia (low levels of white blood cells).

Anemia may cause symptoms such as tiredness or weakness. Leukopenia can make it harder for your body to respond to an infection. Leukopenia may not cause any symptoms, but if it does, symptoms may include:

  • fever or chills
  • trouble breathing
  • abdominal (belly) pain
  • rectal pain

What you can do

Before you begin taking Xeljanz, your doctor will likely order blood tests. This will include tests to check your levels of red and white blood cells. You’ll also have blood tests while you take Xeljanz, to monitor for these side effects.

Upper respiratory infections

Upper respiratory infections are one of the most common side effects of Xeljanz. These infections can include the common cold and sinusitis (pain and swelling in your sinuses).

Symptoms of an upper respiratory infection may include:

  • runny or stuffy nose
  • coughing and sneezing
  • fever
  • headache
  • muscle aches

What you can do

Upper respiratory infections typically go away on their own within a few days. Your doctor or pharmacist may recommend over-the-counter treatments for certain symptoms such as muscle aches or headache. One example of these treatments is acetaminophen (Tylenol).

If you have symptoms that don’t go away on their own, talk with your doctor or pharmacist.

Boxed warnings

Boxed warnings are serious warnings from the Food and Drug Administration (FDA). Xeljanz has several boxed warnings, which are described below.

Cancer and immune system disorders

Cancers, including lymphoma (a type of blood cancer), have been reported in people taking Xeljanz. Xeljanz may also make an existing cancer or malignancy (tumor) worse. This may be due to how Xeljanz treats certain conditions by reducing the activity of the immune system.

If you take the highest dosage of Xeljanz (10 milligrams twice daily), you also have an increased risk for certain skin cancers.

In addition, taking Xeljanz with certain medications that help prevent rejection of a kidney transplant may cause rare but serious problems with your white blood cell levels. This can affect immune system function.

Symptoms of cancer or immune system disorders can vary, but may include:

  • changes to any moles on your skin, such as a mole growing in size or changing color
  • fatigue (lack of energy)
  • frequent infections
  • unintentional or unexplained weight loss

What you can do

Talk with your doctor if you have any of the symptoms listed above. Your doctor will also monitor you for new cancers or immune system problems during your Xeljanz treatment.

And if you’ve had or currently have cancer or a malignancy, be sure to tell your doctor. They’ll help determine the risks and benefits of taking Xeljanz to treat your condition.

Serious infections

Taking Xeljanz increases your risk for serious infections. This is because the drug works by reducing the activity of your immune system.

Symptoms of an infection can vary depending on the type of infection, but in general, symptoms can include:

  • fever or chills
  • fatigue (lack of energy)
  • cough
  • rash

Note: Xeljanz can also cause certain existing infections to become active again. This means you could start to experience symptoms of an active infection. These include herpes zoster (shingles), latent (inactive) tuberculosis (TB), and latent hepatitis B or hepatitis C.

What you can do

If you develop symptoms of a serious infection while taking Xeljanz, contact your doctor to determine what treatment you may need.

Before you start taking Xeljanz, your doctor will test you for TB. If you have TB or another infection before starting Xeljanz, your doctor may recommend treating your infection before you start taking this drug.

Increased risk of blood clots and death

Xeljanz can increase your risk for blood clots and death if:

People who take 10 milligrams (mg) of Xeljanz twice a day are at increased risk for blood clots and death, compared with people taking lower dosages.

Symptoms of a blood clot can include:

  • chest pain
  • trouble breathing or shortness of breath
  • pain or tenderness in your leg
  • swelling, redness, or discoloration in your arm or leg

In serious cases, a blood clot can be fatal.

What you can do

If you have RA, your recommended dosage of Xeljanz will be low, specifically 5 mg twice daily.

If you have symptoms of a blood clot while you’re taking Xeljanz, talk with your doctor right away. Call 911 or get emergency medical help if your symptoms feel life threatening. If you experience a blood clot while taking Xeljanz, your doctor will likely have you stop taking the drug.

Allergic reaction

As with most drugs, Xeljanz can cause an allergic reaction in some people.

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 Xeljanz. But if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Below is important information about precautions to keep in mind before you take Xeljanz.

Boxed warnings

This drug has boxed warnings about increased risk for:

A boxed warning is a serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section above.

Other precautions

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

Digestive tract problems. Taking Xeljanz may cause tears in your digestive tract. People who already have digestive tract problems may be at higher risk for this side effect. Be sure your doctor is aware if you have or have had digestive tract problems, including diverticulitis.

Also make sure your doctor is aware of all the medications you take. Taking nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) can increase your risk for digestive tract problems with Xeljanz.

Blood disorders. Taking Xeljanz may cause blood disorders, including low levels of white blood cells or red blood cells. If you have had or currently have a blood disorder, you may be at higher risk for this side effect. Before you begin taking Xeljanz, your doctor will likely order blood tests that include tests to check your levels of red and white blood cells.

Liver or kidney problems. Xeljanz may not be safe for people with kidney problems (such as severe kidney disease) or liver problems (such as hepatitis C). Talk with your doctor if you have kidney or liver problems before you take this drug. They may prescribe a low dosage of Xeljanz for you. Or your doctor may recommend a different medication to treat your condition.

Allergic reaction. You should not take Xeljanz if you’ve ever had an allergic reaction to the drug or any of its ingredients. Talk with your doctor about which other treatments are better choices for you.

Alcohol use with Xeljanz

There aren’t any known interactions between alcohol and Xeljanz. However, some conditions Xeljanz is used to treat may be made worse by alcohol.

Talk with your doctor to see if it’s safe for you to drink alcohol while taking Xeljanz.

Pregnancy and breastfeeding while taking Xeljanz

It’s not known if it’s safe to take Xeljanz while pregnant. Your doctor can recommend a safe treatment for your condition during your pregnancy, and help weigh the risks and benefits of using Xeljanz while pregnant.

The manufacturer of Xeljanz recommends against breastfeeding while taking the medication. If you’re breastfeeding or planning to breastfeed, talk with your doctor about safe ways to feed your baby while taking this drug. You can also ask about other medications that may be safe to use while breastfeeding.

Side effects from Xeljanz can occur, including mild and serious side effects. Many people who take the drug don’t have side effects. And most mild side effects of the drug go away in time, without medical attention.

You should contact your doctor if you experience symptoms of serious side effects, which are described above in the “Serious side effects of Rexulti” section. If you become pregnant while you’re taking Xeljanz, you should also tell your doctor right away.

If you’d like to learn more about Xeljanz, 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 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.