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Pronunciation: ZEL’ JANS’
Generic name: tofacitinib
Dosage form: oral tablet, extended-release tablet, oral solution
Drug class: Antirheumatics

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 22, 2023.

What is Xeljanz?

Xeljanz (tofacitinib) is an oral Janus kinase (JAK) inhibitor that may be used alone or with other medications to reduce inflammation associated with inflammatory and autoimmune conditions such as rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis.

Xeljanz works by decreasing the activity of the immune system. It does this by blocking the activity of JAK enzymes (JAK1, JAK2, JAK3, TYK2) inside the cell – these enzymes are responsible for sending inflammatory signals in the body which are associated with cytokine release. By blocking these enzymes Xeljanz helps to decrease the immune reaction which causes rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis.

Xeljanz may be used to treat the following conditions in adults who are unable to take or did not respond to one or more tumor necrosis factor (TNF) inhibitor medication(s)

Xeljanz is also approved to treat polyarticular juvenile idiopathic arthritis in patients 2 years of age and older who have had an inadequate response or intolerance to one or more TNF blockers.

Xeljanz was FDA approved on November 6, 2012.


Taking Xeljanz may increase your risk of life-threatening medical problems including serious infections, a hole or tear in your digestive tract, a heart attack or stroke, blood clots, or cancer.

Tell your doctor if you have a weak immune system, diabetes, chronic lung disease, or an infection such as hepatitis, tuberculosis, shingles, or HIV. Also tell your doctor if you've ever had diverticulitis, an ulcer in your stomach or intestines, cancer, a kidney transplant, heart problems, or a history of smoking, heart attack, stroke, or blood clots.

Call your doctor right away if you have a fever, night sweats, constant tiredness, weight loss, stomach pain, diarrhea or changes in bowel habits, trouble breathing, wheezing, a severe cough, or lumps in your neck, armpits, or groin.

Seek emergency medical help if you have sudden shortness of breath, chest pain spreading to your neck or arms, nausea, severe dizziness, a cold sweat, weakness on one side of your body, slurred speech, or pain, redness, or swelling in an arm or leg.

The use of Xeljanz in combination with biologic DMARDs or potent immunosuppressants such as azathioprine and cyclosporine is not recommended.

Xeljanz XR (extended-release tablets) are not interchangeable or substitutable with Xeljanz Oral Solution.

Xeljanz should not be started in patients with an absolute lymphocyte count less than 500 cells/mm3, absolute neutrophil counts (ANC) <1000 cells/mm3, or hemoglobin <9 g/dL.

Do not use in patients with severe hepatic impairment. Avoid use during an active serious infection, including localized infections.

Regular laboratory monitoring is recommended due to potential changes in lymphocytes, neutrophils, hemoglobin, liver enzymes, and lipids.

Before taking this medicine

Tell your doctor if you've had:

Tell your doctor if you've been sick with signs of infection, such as fever, chills, muscle aches, cough, trouble breathing, skin sores, diarrhea, or painful urination.

Tell your doctor if you've had or been exposed to tuberculosis, or if you recently traveled. Some infections are more common in certain parts of the world, and you may have been exposed during travel.

Also to make sure Xeljanz is safe for you, tell your doctor if you have ever had:

Using Xeljanz may increase your risk of developing certain cancers, such as lymphoma or lung cancer. Ask your doctor about this risk.

Tell your doctor if you are pregnant or plan to become pregnant. Having rheumatoid arthritis or ulcerative colitis during pregnancy may increase the risk of premature birth or low birth weight. The benefit of treating these conditions with Xeljanz may outweigh any risks to the baby. If you become pregnant while taking Xeljanz, your name may be recorded on a pregnancy registry to track the effects of Xeljanz on the baby.

If you are a woman, Xeljanz may affect your fertility and your ability to have children during treatment and in the future.

Do not breastfeed while you are using this medicine, and for at least 18 hours after your last dose (36 hours if you take extended-release tablets). If you use a breast pump during this time, do not feed the milk to your baby.

Do not give this medicine to a child without medical advice. The extended-release tablets are not approved for use by anyone younger than 18 years old.

How do I take Xeljanz?

Take Xeljanz exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

You may take Xeljanz with or without food.

Swallow the extended-release tablet whole and do not crush, chew, or break it.

Measure liquid medicine with the supplied measuring device (not a kitchen spoon).

Doses are based on weight in children and teenagers. Your child's dose may change if the child gains or loses weight.

Dosing information

Adults with Rheumatoid Arthritis, Psoriatic Arthritis, or Ankylosing Spondylitis

Reduce dosage to 5mg once daily in those with moderate to severe renal impairment or moderate hepatic impairment.

Psoriatic arthritis: use in combination with nonbiologic DMARDs.

Adults with Ulcerative Colitis

Immediate-Release Tablets:

Extended-Release Tablets:

If needed, induction dosages may be continued for up to 16 weeks; if adequate therapeutic response is not achieved after 16 weeks, the induction dosage should be discontinued.

For patients with loss of response during maintenance therapy, consider 10 mg orally twice a day (immediate-release tablets) or 22 mg orally once a day (extended-release tablets) for a short duration. Use the lowest effective dose needed to maintain a response.

Juvenile Idiopathic Arthritis in Children 2 Years and Older

Oral solution:

Immediate-release tablets:

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Xeljanz?

Avoid receiving a "live" vaccine. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

Xeljanz side effects

Get emergency medical help if you have signs of an allergic reaction to Xeljanz, such as hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Some people taking Xeljanz have developed heart attacks, strokes, or serious blood clots. Stop taking this medicine and seek emergency medical attention if you have:

Xeljanz may cause serious side effects. Call your doctor at once if you have:

Common Xeljanz side effects may include:

Patients receiving Xeljanz XR may notice an inert tablet shell passing in the stool or via colostomy. The active medication has already been absorbed by the time the inert tablet shell is seen.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Xeljanz?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Tell your doctor about all your current medicines. Many drugs can interact with tofacitinib, especially:

This list is not complete and many other drugs may interact with tofacitinib. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.


Active ingredient: tofacitinib citrate

Inactive ingredients:


Store Xeljanz and Xeljanz XR at room temperature between 68°F to 77°F (20°C to 25°C).

Store Xeljanz Oral Solution at room temperature between 68°F to 77°F (20°C to 25°C). Use within 60 days of opening the bottle. Throw away (discard) the remaining solution after 60 days. Write the date when you first start to use the solution on the carton.

Keep it in the original bottle and carton to protect it from light.

Keep out of reach of children.


Pfizer Labs, Division of Pfizer Inc.

Popular FAQ

Janus kinase (JAK) inhibitors are a group of medicines that help block immune system signals in the body that can lead to swelling (inflammation) and pain in conditions like rheumatoid arthritis, ulcerative colitis, and psoriatic arthritis. They work by blocking enzymes that lead to overactivity of the immune system. Continue reading

Stopping treatment with Xeljanz may cause the symptoms of your condition to return. However, some patients are able to stop Xeljanz without their symptoms flaring up, according to the results of research conducted in patients with rheumatoid arthritis. You should not stop taking Xeljanz without consulting your doctor. Continue reading

List of JAK inhibitors approved in the United States include:

  • Cibinqo (abrocitinib)
  • Inrebic (fedratinib)
  • Jakafi (ruxolitinib)
  • Litfulo (ritlecitinib)
  • Ojjaara (momelotinib)
  • Olumiant (baricitinib)
  • Opzelura (ruxolitinib)
  • Rinvoq (upadacitinib)
  • Vonjo (pacritinib)
  • Xeljanz (tofacitinib)
Continue reading

Xeljanz can work in as little as three days for patients with ulcerative colitis. Some patients with rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis and ankylosing spondylitis will notice an improvement in their symptoms within two weeks, but others may have to wait up to three to four months for Xeljanz to work.

Xeljanz (tofacitinib citrate) is a Janus kinase (JAK) inhibitor and disease modifying anti-rheumatic drug (DMARD), which works by suppressing the immune system. Continue reading

Although the manufacturer of Xeljanz, Pfizer, does not warn of an interaction between alcohol and Xeljanz, you should not drink excessive amounts of alcohol while you are taking Xeljanz because both are metabolized by the liver and can cause liver damage. The risk may be higher if you take other immunosuppressants or medications that also affect the liver, such as methotrexate, or already have liver disease. There have already been numerous Xeljanz lawsuits filed by people who believe Pfizer should have warned them about the dangers of combining alcohol and Xeljanz. Continue reading

Hair loss is not a side effect of Xeljanz. In fact, Xeljanz is sometimes used off-label to treat hair loss in patients with alopecia areata. Treatment with Xeljanz leads to hair regrowth in some patients with alopecia areata, although hair shedding occurs once treatment is stopped. Continue reading

Xeljanz (tofacitinib) is a biologic medicine classified as Janus kinus (JAK) inhibitor and is used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis and ulcerative colitis in adults and for polyarticular juvenile idiopathic arthritis in patients 2 years and older. Continue reading

Xeljanz (tofacitinib citrate) can interact with other medications, including certain antibiotics and antifungal medications. In some cases the interaction means that it is not recommended to take Xeljanz and the other drug at the same time, while in other cases it simply means that the dose of Xeljanz you take will need to be reduced. Continue reading

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.