As with other drugs, Xeljanz and Xeljanz XR (tofacitinib) can cause side effects, such as upper respiratory infection and headache. If you’re not able to tolerate side effects of Xeljanz, talk with your doctor or pharmacist.

Xeljanz and Xeljanz XR are prescription brand-name medications approved by the Food and Drug Administration (FDA) to treat the following conditions in adults:

These medications 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:

  • Active ingredient: tofacitinib
  • Drug class: Janus kinase inhibitor
  • Drug forms:
    • Xeljanz immediate release: oral tablet and oral solution
    • Xeljanz XR extended release: oral tablet

For a general overview of these drugs, including details about their uses, see this Xeljanz overview article.

These drugs have boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Boxed warnings for Xeljanz and Xeljanz XR” section.

These are just a few of the more common side effects reported by people who took tofacitinib in clinical studies. (Tofacitinib is the active ingredient in Xeljanz and Xeljanz XR.) These side effects can vary depending on which condition either drug is being used to treat.

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

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

Mild side effects can occur with Xeljanz and Xeljanz XR. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to the prescribing information for these drugs.

Mild side effects of Xeljanz and Xeljanz XR may include:

These side effects may be temporary, lasting a few days or weeks. However, 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 or Xeljanz XR and want to tell the FDA about it, visit MedWatch.

Xeljanz and Xeljanz XR 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 the prescribing information for these drugs.

If you develop serious side effects while taking Xeljanz or Xeljanz XR, 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 of Xeljanz and Xeljanz XR may include:

These side effects are discussed in the “Side effect specifics” and “Boxed warnings for Xeljanz and Xeljanz XR” sections.

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 and Xeljanz XR aren’t known to cause hair loss or hair growth. These effects weren’t reported as side effects in clinical trials.

According to a review of some small clinical trialsTrusted Source, the active ingredient (tofacitinib) in Xeljanz and Xeljanz XR might be an effective treatment for hair loss that’s caused by alopecia areata (an autoimmune disease). However, more studies are needed to confirm this. At this time, these drugs are not approved to treat hair loss.

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

Is depression a side effect of Xeljanz?

No, Xeljanz and Xeljanz XR shouldn’t cause depression. It wasn’t reported as a side effect in clinical trials.

Keep in mind that it’s not uncommon for depression to occur in people who have the conditions that Xeljanz and Xeljanz XR treat, such as psoriatic arthritis (PsA). In fact, some studiesTrusted Source suggest that treating PsA may also help reduce depression in people who have both of these conditions.

If you have questions about depression or how taking Xeljanz or Xeljanz XR 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 either drug.

In fact, some of the possible serious side effects of Xeljanz and Xeljanz XR can lead to unexplained weight loss. This includes serious infections or diarrhea, for example. (These drugs have a boxed warning about the risk of serious infections. For details, see the “Boxed warnings for Xeljanz and Xeljanz XR” section.)

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, taking Xeljanz or Xeljanz XR shouldn’t affect your eyes. Eye-related side effects weren’t reported in clinical trials.

It’s important to note that if you have hepatitis B or hepatitis C, Xeljanz or Xeljanz XR can cause the virus to become active again. This can cause symptoms of a hepatitis infection, such as jaundice (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 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 Xeljanz or Xeljanz XR treatment. However, stopping treatment with either drug could cause symptoms of your condition to return.

You should not stop taking Xeljanz or Xeljanz XR without speaking with your doctor first about the risks and benefits of doing so. If you and your doctor determine that stopping the 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 or Xeljanz XR treatment.

If I take Xeljanz XR and notice an undigested tablet in my stool, is this normal?

It’s possible. Xeljanz XR is an extended-release tablet, and this type of tablet can sometimes pass into your stool. Even if the tablet appears to be intact, your body has absorbed the active ingredient.

This situation isn’t a cause for concern. In fact, it commonly occurs with other extended-release medications. (Extended-release drugs are released slowly over time in your body after they’re taken.)

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

Tears in the digestive tract

Although rare, Xeljanz and Xeljanz XR 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 abdominal 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 with Xeljanz or Xeljanz XR, 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 call your doctor right away if you have a fever, abdominal pain that doesn’t go away, or any changes in your bowel habits.

Blood disorders

Taking Xeljanz or Xeljanz XR 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 pain
  • sore throat
  • rash

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 during the treatment to monitor for these side effects.

Upper respiratory infections

Upper respiratory infections are one of the most common side effects of Xeljanz and Xeljanz XR. 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.

Allergic reaction

As with most drugs, Xeljanz and Xeljanz XR 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 or Xeljanz XR.

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

Boxed warnings are serious warnings from the Food and Drug Administration (FDA). Xeljanz and Xeljanz XR have boxed warnings about the following risks, which are described below:

Risk of cancer and immune system disorders

Cancers, including lymphoma (a type of blood cancer), have been reported in people taking Xeljanz.

Xeljanz and Xeljanz XR may also make an existing cancer or malignancy (tumor) worse. This may be due to how the medications treat certain conditions by reducing the activity of the immune system.

If you take the highest dosage of Xeljanz (10 milligrams [mg] twice daily), you also have an increased risk for certain skin cancers. This also applies if you take the highest dosage of Xeljanz XR (22 mg once daily).

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
  • frequent infections
  • unintentional or unexplained weight loss

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 treatment.

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 or Xeljanz XR to treat your condition.

Risk of serious infections

Taking Xeljanz or Xeljanz XR 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
  • cough
  • rash

Note: Xeljanz and Xeljanz XR 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.

If you develop symptoms of a serious infection while taking Xeljanz or Xeljanz XR, call your doctor to determine if treatment is needed.

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

Risk of blood clots

Xeljanz and Xeljanz XR may increase your risk for blood clots and death if:

The risk of blood clots may be further increased with higher dosages of Xeljanz or Xeljanz XR.

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.

If you have symptoms of a blood clot while you’re taking either drug, tell 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 or Xeljanz XR, your doctor will likely have you stop taking the drug.

Risk of death in certain people

Certain people taking Xeljanz may have an increased risk of death, including death related to a cardiovascular issue. This applies to people with rheumatoid arthritis (RA) who are ages 50 years or older and have at least one cardiovascular risk factor.

Your doctor can describe whether this drug is right for you based on your risk factors. They’ll recommend the dosage and treatment length of Xeljanz or Xeljanz XR that’s safest for you.

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

Boxed warnings

Xeljanz and Xeljanz XR have boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Boxed warnings for Xeljanz and Xeljanz XR” section.

Other precautions

Be sure to talk with your doctor about your health history before you take Xeljanz or Xeljanz XR. 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:

Alcohol use with Xeljanz

There aren’t any known interactions between alcohol and Xeljanz or Xeljanz XR. However, some conditions that the drugs are 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 or Xeljanz XR.

Pregnancy and breastfeeding while taking Xeljanz

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

The manufacturer of both drugs recommends that you don’t breastfeed while taking the medication. If you’re breastfeeding or planning to breastfeed, talk with your doctor about safe ways to feed your child while taking either drug. You can also ask about other medications that may be safe to use while breastfeeding.

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.