If you have rheumatoid arthritis (RA), alopecia areata, or severe COVID-19, your doctor might suggest Olumiant. It’s a prescription medication used in adults to treat:

  • moderate to severe RA, when certain other medications haven’t worked well enough
  • severe alopecia areata
  • severe COVID-19, as part of hospital treatment that also includes breathing assistance

Olumiant comes as a tablet you swallow. It contains the active ingredient baricitinib. Olumiant isn’t currently available as a generic.

If you and your doctor agree Olumiant is working well for you, you’ll likely take it long term for RA or alopecia areata. For COVID-19, you’ll take Olumiant for 14 days or until you leave the hospital, whichever comes first. For more information about Olumiant, including details about its uses, see this in-depth article.

Like other drugs, Olumiant can cause mild to serious side effects (also referred to as adverse effects). Keep reading to learn more.

Some people may experience mild to serious side effects during their Olumiant treatment. Examples of commonly reported side effects of this drug include:

These are just a few of the side effects Olumiant may cause, but side effects won’t happen to everyone. Read on to learn more about mild to serious side effects of Olumiant.

Like most drugs, Olumiant can cause mild side effects. But only a few were reported by people taking Olumiant in the drug’s studies.

Examples of mild side effects reported with Olumiant 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 that bother you, talk with your doctor or pharmacist. And don’t stop using Olumiant unless your doctor recommends it.

Olumiant may cause mild side effects other than the ones listed above. See the Olumiant prescribing information for details.

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

Treatment with Olumiant can cause serious side effects, but they aren’t common. Serious side effects reported with Olumiant include:

If you develop serious side effects while taking Olumiant, call your doctor right away. But you should immediately call 911 or your local emergency number if:

  • the side effects seem life threatening
  • you think you’re having a medical emergency

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

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

Can Olumiant cause long-term side effects?

While rare, treatment with Olumiant can cause long-term side effects. These side effects may start during treatment but continue for a long time, possibly after treatment has stopped.

Long-term side effects reported by people taking Olumiant in studies include:

Olumiant has boxed warnings about the risk of these side effects. This is the most serious warning from the Food and Drug Administration (FDA).For more information about these side effects, see “Side effects explained” below.

You can also talk with your doctor or pharmacist to learn more about potential long-term side effects from Olumiant therapy.

Is it possible to have weight gain from taking Olumiant?

No, weight gain wasn’t reported as a side effect by people taking Olumiant in studies. But certain other medications used to treat rheumatoid arthritis (RA), including corticosteroids such as prednisone (Rayos), can cause weight gain.

RA, which Olumiant is used to treat, can cause symptoms such as joint pain. This can make it hard to be physically active, which can lead to weight gain in people with RA. Olumiant helps make RA symptoms less severe, which can make it easier to exercise.

If you’re concerned about weight gain and your treatment plan, talk with your doctor. They can suggest ways to maintain a weight that’s healthy for you.

Will Olumiant cause hair loss?

No, it’s not expected to. In fact, Olumiant is approved to treat hair loss due to alopecia areata. This condition causes hair loss that can affect your entire body.

Hair loss isn’t a side effect reported in studies of Olumiant. But RA, which Olumiant is used to treat, may cause hair loss. Other medications that treat RA can also cause hair loss as a side effect, including:

Talk with your doctor if you’re concerned about hair loss with Olumiant treatment.

Can Olumiant cause tiredness?

No, tiredness isn’t a known side effect of Olumiant. People taking this drug in studies didn’t report tiredness as a side effect.

Keep in mind that Olumiant may cause a low level of red blood cells. And fatigue (low energy) is often a symptom of this condition. If you have fatigue while taking Olumiant, your doctor may check your red blood cell level to see if this could be the cause.

It’s common for people with rheumatoid arthritis (RA) or severe COVID-19 to have fatigue and tiredness. Some people report this as the worst symptom of RA. Olumiant may help reduce tiredness.

Some other medications used to treat RA can cause fatigue as a side effect, including Trexall (methotrexate).

Talk with your doctor if you have tiredness that bothers you. They can review your treatment plan.

Is there a 4-mg dose of Olumiant? If so, are there any side effects specific to it?

Yes, Olumiant comes in a strength of 4 milligrams (mg). Olumiant can be prescribed in a 4-mg dose for some conditions. Side effects of a 4-mg dose are expected to be the same as those caused by a 2-mg dose.

An Olumiant dosage of 4 mg taken once per day is recommended for severe COVID-19. A 4-mg dose can be prescribed for severe alopecia areata as well. A 4-mg dose isn’t usually prescribed for RA, however.

You can see this article for details about Olumiant’s recommended dosages. Be sure to follow the dosage your doctor prescribes for you.

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

Serious infections

Olumiant increases your risk of infection. The drug has a boxed warning about this side effect. This is the most severe warning the Food and Drug Administration (FDA) can give a medication. It alerts doctors and patients about the most serious side effects a drug can cause.

In rare cases, this can include serious infection, such as pneumonia and shingles. And in extreme instances, people have developed life threatening infections while taking Olumiant.

Olumiant works by reducing the activity of your immune system, which is why it increases your risk of infection.

Symptoms of infection can vary depending on the type but can include:

Other medications you take, including other medications that treat rheumatoid arthritis (RA), can also increase your risk of infection. These include:

Certain people are at higher risk of infection if they take Olumiant. This includes people who have:

  • a long-term or recurrent infection
  • been exposed to tuberculosis (TB) or lived somewhere with widespread TB
  • lived or traveled to places with a higher risk of certain fungal infections
  • certain medical conditions that weaken the immune system

Taking Olumiant can reactivate certain viruses if you’ve been exposed to them before. (When a virus is reactivated, it causes symptoms of infection after not causing any for a long time.) Viruses that may be reactivated by taking Olumiant include:

What might help

Before prescribing Olumiant, your doctor will likely test you for tuberculosis. They may also check you for other infections. If these tests are active, your doctor will likely want to treat the infection before prescribing Olumiant.

Before starting Olumiant treatment, be sure to tell your doctor if you have:

  • any active infections
  • any of the risk factors for infections mentioned above

Your doctor will use this information to help decide if Olumiant is safe for you to take.

While taking Olumiant, your doctor will closely watch you for any signs of infection. If you develop symptoms of an infection, contact your doctor right away. They’ll want to see you and order tests to confirm. If the tests are positive, they’ll prescribe treatment, such as an antibiotic or antifungal.

If you develop an infection during Olumiant treatment, your doctor may have you stop taking the drug temporarily. Your doctor will then wait until the infection clears before having you resume treatment with Olumiant.

Cancer

Although extremely rare, several people developed certain cancers while taking medications similar to Olumiant in studies. Because Olumiant is similar to these medications, the drug has a boxed warning about this side effect.

Specifically, you may be at increased risk of developing lymphoma, a type of blood cancer. People who smoke or previously smoked have an increased risk of cancer, including lung cancer, if they take Olumiant or similar drugs.

Also, people taking Olumiant in studies had a higher risk of developing nonmelanoma skin cancers compared to those who took a placebo. (A placebo is a treatment with no active drug.)

Because Olumiant works by reducing the activity of your immune system, it increases the risk of developing certain cancers.

What might help

Before starting Olumiant, be sure to discuss with your doctor any medical conditions you have and medications you take. Your doctor will use this information to help determine your risk of developing cancer and whether Olumiant is safe for you.

Blood clots

While very rare, some people developed blood clots while taking Olumiant in studies. This drug has a boxed warning about this side effect.

Clots reported by people taking Olumiant include:

Symptoms of a blood clot can include:

What might help

Call your doctor right away or seek emergency care if you notice symptoms of a blood clot while taking Olumiant. These blood clots can be life threatening and require treatment in a hospital.

Serious cardiovascular problems

Although rare, several people developed certain cardiovascular (heart and blood vessel) problems while taking medications similar to Olumiant in studies. Because Olumiant works in a similar way to the drugs in the study, it has a boxed warning about this side effect.

Cardiovascular problems caused by Olumiant and drugs like it include heart attack and stroke.

Symptoms of a heart attack can include:

Symptoms of a stroke can include sudden:

  • numbness or weakness in your arm, face, or leg, especially on one side of your body
  • speech problems, such as trouble speaking
  • trouble walking or coordination problems
  • vision problems, such as trouble seeing out of one eye

If you smoke, or have smoked in the past, you’re at higher risk of serious cardiovascular problems if you take Olumiant. You’re also at higher risk if you already have risk factors for cardiovascular problems, such as:

What might help

If you notice symptoms of a serious cardiovascular problem, including heart attack or stroke, while taking Olumiant:

  • call your doctor right away
  • seek emergency medical care

These problems can be life threatening and usually require treatment in a hospital.

Before you begin Olumiant, your doctor will discuss with you the risks and benefits of this medication. This should include a discussion about your risk of serious cardiovascular problems.

If your doctor prescribes Olumiant to you, they’ll monitor your cardiovascular health. And they’ll have you stop taking Olumiant if you have a serious cardiovascular problem during treatment.

Increased risk of death

Olumiant has a boxed warning about increased risk of death in certain people. This is because certain people taking a drug similar to Olumiant in a study had a higher risk of death compared with other medications used to treat rheumatoid arthritis. Because the drugs work in a similar way, Olumiant has a boxed warning about this side effect.

Specifically, people over the age of 50 years who had at least one risk factor for cardiovascular problems were at increased risk of death in this study. (See the “Serious cardiovascular problems” section above.)

What might help

Your doctor will discuss with you the risks and benefits of taking Olumiant. If they prescribe this medication for you, they may monitor your health closely during treatment. Your doctor will talk with you about your health and any risks you may have from Olumiant treatment.

Allergic reaction

Like most drugs, Olumiant can cause an allergic reaction in some people. It isn’t known how often allergic reaction occurred during the drug’s studies.

Symptoms can be mild or serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically 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 the following to help you manage your symptoms:

If your doctor confirms you had a mild allergic reaction to Olumiant, they’ll decide if 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 had a serious allergic reaction to Olumiant, they may have you switch to a different treatment.

Keeping track of side effects

During your Olumiant treatment, consider keeping notes on any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful to do when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of drug you were taking when you had the side effect
  • how soon after starting that dose you had the side effect
  • what your symptoms were
  • how it 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 your doctor learn more about how Olumiant affects you. And your doctor can use this information to adjust your treatment plan if needed.

When considering treatment with Olumiant, it’s important to discuss your overall health with your doctor. Treatment with Olumiant may not be right for you if you have certain medical conditions. Below is more information on certain possible risks of taking Olumiant.

Boxed warnings

Olumiant has the following boxed warnings. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

  • Serious infections. Treatment with Olumiant increases your risk of infection, including serious infections such as pneumonia, shingles, and tuberculosis (TB). In extreme cases, these infections can be life threatening.
  • Cancer. Taking Olumiant may increase your risk of developing certain cancers, including lymphomas and nonmelanoma skin cancers.
  • Blood clots. Although very rare, serious blood clots have been reported in people taking Olumiant. In rare cases, these blood clots can be life threatening.
  • Serious cardiovascular problems. While rare, some people taking medications similar to Olumiant in studies had serious cardiovascular (heart and blood vessel) problems. These included heart attack and stroke. The way Olumiant works is similar to these medications, so it’s thought that it could also increase your risk of serious cardiovascular problems.
  • Increased risk of death in certain people. Certain people taking medications similar to Olumiant had an increased risk of death in a study. Because it works similarly to these medications, it’s thought Olumiant could also increase this risk in certain people.

To learn more, see the “Side effects explained” section above.

Other warnings

Olumiant may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before starting Olumiant. The list below includes factors to consider.

Active infection. If you have an infection that’s active (causing symptoms), your doctor will likely wait for it to clear before prescribing Olumiant for you.

Diverticulitis, or ulcers in your intestines or stomach. While rare, taking Olumiant can cause holes in your intestines or stomach as a side effect. If you have diverticulitis or ulcers in your intestines or stomach, you may be at higher risk of this side effect. In this case, your doctor can help determine whether it’s safe for you to take Olumiant.

Increased risk of infection. Treatment with Olumiant increases your risk of infection, including serious infections such as pneumonia and tuberculosis (TB). If you’re already at increased risk of infection, this risk may be even higher if you take Olumiant. Your doctor can help determine whether Olumiant is safe for you to take.

Kidney problems. Your kidneys help get rid of Olumiant after you take a dose. If you have kidney problems, including chronic kidney disease, your kidneys may not be able to clear Olumiant from your body. And this can increase your risk of side effects from the medication, including more damage to your kidneys. Depending on the severity of your kidney problems, your doctor may prescribe a lower Olumiant dose or suggest a different treatment option.

Liver problems, including hepatitis B or C. Elevated liver enzymes have been reported as a side effect with Olumiant. This can be a sign of liver damage. People who already have liver problems, such as hepatitis B or hepatitis C, may be at higher risk of this side effect. Taking Olumiant could also worsen your liver problems, or cause hepatitis to become active again. Your doctor can help determine whether Olumiant is safe for you to take.

Tuberculosis. Tell your doctor if you’ve previously had tuberculosis (TB). Taking Olumiant could cause TB to become active and the symptoms to return. Your doctor can help determine whether Olumiant is safe for you to take.

Allergic reaction. If you’ve had an allergic reaction to Olumiant or any of its ingredients, your doctor will likely not prescribe it for you. Ask your doctor what other medications might be better treatment options.

Alcohol use and Olumiant

There’s no known interaction between drinking alcohol and taking Olumiant. But drinking alcohol could increase your risk of nausea, a possible mild side effect caused by Olumiant.

If you’re taking Olumiant for rheumatoid arthritis (RA), keep in mind that other RA drugs can interact with alcohol.

If you drink alcohol, it’s recommended that you do so in moderation. Talk with your doctor about how much alcohol, if any, is safe to consume while taking Olumiant.

Pregnancy and breastfeeding while taking Olumiant

It’s not known whether Olumiant is safe to take while pregnant. Talk with your doctor if you’re pregnant or thinking of becoming pregnant before you take Olumiant.

It also isn’t known whether Olumiant passes into human breast milk. But due to the potential risk of side effects, your doctor will likely recommend you don’t breastfeed while taking Olumiant. They can recommend safe feeding options for your child.

Olumiant can be an effective treatment for people with rheumatoid arthritis (RA), alopecia areata, or severe COVID-19.

There weren’t many mild side effects reported in studies of Olumiant. And while Olumiant can cause some serious side effects, these are rare, with certain people being at higher risk. (See the “Warnings for Olumiant” section above for details.)

Olumiant also has several boxed warnings, the most serious warning a drug can be given by the Food and Drug Administration (FDA). See the “Side effects explained” section above for more information.

Talk with your doctor or pharmacist if you’re interested in learning more about taking Olumiant for RA. Some questions to consider asking are:

  • Are there ways I can reduce my risk of side effects from Olumiant?
  • If I develop side effects while taking Olumiant, can I take a lower dose?
  • Do other medications that I take increase my risk of side effects with Olumiant?

Be sure to contact your doctor if you develop symptoms of a serious side effect while taking Olumiant. See the “Side effects explained” section above for more information on the symptoms to watch for.

You can get more information on conditions such as RA and COVID-19 by signing up for one of our newsletters. You can also get advice and other resources from the Bezzy RA community.

Q:

Are there lab tests my doctor will order to check for side effects if I begin taking Olumiant?

Anonymous

A:

Yes, your doctor may give you lab tests to check for side effects with Olumiant.

Below are a few tests your doctor may order to check for side effects of the drug:

If you’ve had certain infections in the past, Olumiant may reactivate them. This means you may have symptoms of these conditions again after not having any for a long time. In this case, your doctor may give you tests to check for these infections before you start the drug. Examples include tuberculosis (TB) and hepatitis B or hepatitis C.

If you have questions about lab tests you’ll need with Olumiant, talk with your doctor.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
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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.