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

For each of these conditions, Enbrel is typically used as a long-term treatment. Since Enbrel works by weakening certain parts of the immune system, infections are its most common side effect.

Here are some fast facts on Enbrel:

Read on to learn about potential common, mild, and serious side effects. For a general overview of Enbrel, including details about its uses, see this article.

Enbrel can cause certain side effects, some of which are more common than others. 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.

These are just a few of the more common side effects reported by people who took Enbrel in clinical trials:

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

Mild side effects that have been reported with Enbrel can 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 Enbrel and want to tell the FDA about it, visit MedWatch.

Enbrel may cause serious side effects. The list below may not include all possible serious side effects or complications of the drug. For more information, you can refer to Enbrel’s medication guide.

If you develop serious side effects while taking Enbrel, 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 and their symptoms can include:

* For information on this side effect, see “Side effect specifics” below.
Enbrel 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.

Long-term side effects

Enbrel is typically used long term. Its long-term side effects are similar to the effects that can occur with short-term use. If you’re concerned about long-term side effects from taking Enbrel, talk with your doctor.

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

Are there any side effects that can occur when stopping Enbrel treatment?

No, stopping Enbrel won’t cause side effects. However, symptoms of your condition may return or worsen when you stop taking the drug. For this reason, do not stop taking Enbrel without talking with your doctor first.

If you’re concerned about side effects when stopping Enbrel, make sure to discuss this with your doctor.

Is hair loss a side effect of Enbrel?

No, hair loss wasn’t reported as a side effect by people taking Enbrel in clinical studies. However, it’s possible for hair loss to happen with certain serious side effects of Enbrel, such as cancer or an infection.

Talk with your doctor if you’re concerned about hair loss while taking Enbrel.

What does Enbrel do to the body?

Enbrel is a type of drug called a tumor necrosis factor (TNF) blocker. TNF is a protein produced by the body that can cause inflammation (damage and swelling). Enbrel works to block (stop the action of) TNF, which lowers the amount of inflammation in your body. This can help relieve symptoms of the conditions Enbrel is approved to treat.

If you have other questions about how Enbrel works, talk with your doctor or pharmacist.

How do Enbrel’s side effects compare with those of Humira?

Enbrel and Humira are used to treat many of the same conditions. Both drugs are classified as tumor necrosis factor (TNF) blockers,* so they can cause some very similar side effects. But they can also cause some different ones, as shown in the chart below.

* TNF blockers are a type of drug that works to reduce inflammation (damage and swelling).

Mild side effectsSerious side effects
Can occur with Enbrel• fever
• itchiness
no unique serious side effects
Can occur with Humira• abdominal (belly) pain
• headache
• nausea
no unique serious side effects
Can occur with both Enbrel and Humira (when used separately)diarrhea
• injection site reactions
• respiratory infections
• rash
allergic reaction
blood disorders, including pancytopenia
• certain cancers, such as lymphoma and skin cancer
congestive heart failure
lupus-like syndrome
• new or worsening nerve conditions, such as optic neuritis
• serious infections, including reactivation of tuberculosis

For more information on how these drugs compare, see this article.

Enbrel and Humira both have 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.

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

Neurological reactions

Although rare, tumor necrosis factor (TNF) blockers* such as Enbrel can cause neurological reactions or problems. This refers to problems that affect the nervous system (brain and spinal cord), such as multiple sclerosis or seizures. Very rarely, these reactions may cause permanent disability.

Symptoms of neurological reactions can include:

  • dizziness
  • numbness or tingling in your body
  • weakness in your arms and legs

* TNF blockers are a type of drug that works to reduce inflammation (damage and swelling).

Eye-related side effects

Taking Enbrel may also cause inflammation (damage and swelling) in the nerves of your eyes. This is a possible type of neurological reaction to the drug. Inflammation that occurs in your optic nerve (the nerve that connects the eye and the brain) is called optic neuritis.

Symptoms of optic neuritis can include:

  • pain in your eye
  • seeing flashing lights in one or both eyes
  • vision loss, typically in one eye

What you can do

Before taking Enbrel, you and your doctor will discuss the pros and cons of treatment. This includes your risk for neurological reactions. Be sure your doctor is aware of all your medical conditions, especially any conditions you may have related to your nervous system.

If you have symptoms of a neurological reaction, including eye-related side effects, call your doctor right away. They may recommend a treatment other than Enbrel.

Rash

It’s possible to experience a rash from taking Enbrel. This side effect wasn’t very common in clinical trials of the drug. And in most cases the rash was mild. Symptoms of a rash can include skin redness, discoloration, irritation, itchiness, or raised bumps.

However, a rash can also be a symptom of more serious side effects of Enbrel. These may include an allergic reaction or lupus-like syndrome (a condition that causes some symptoms similar to lupus). Also, depending on the condition you’re taking Enbrel to treat, a rash from Enbrel may be hard to tell apart from symptoms of your condition.

What you can do

If you think you might have a rash, call your doctor. Do not rely on pictures online to try to determine whether you have a rash. Your doctor will likely want to examine you to see what could be causing your rash and how to treat it.

Treatment for a rash may include an over-the-counter cream, if you have itching. Your doctor may also suggest stopping Enbrel and trying a different treatment.

Congestive heart failure

Rarely, Enbrel can cause congestive heart failure. The drug may also worsen congestive heart failure if you already have this condition.

With congestive heart failure, your heart is weakened and no longer efficiently pumps blood around your body. Symptoms can include:

  • dry, hacking cough
  • shortness of breath
  • fluid retention (excess fluid in the body), which may cause swelling in your hands or feet
  • fatigue (lack of energy)
  • dizziness
  • irregular heart rate

What you can do

Call your doctor right away if you notice new or worsening symptoms of congestive heart failure. They may have you try a treatment other than Enbrel.

If you already have congestive heart failure and you’re prescribed Enbrel, make sure your doctor knows about your condition. You’ll be monitored more closely than usual during your treatment.

Serious infections

Enbrel has a boxed warning about increased risk of serious infections. A boxed warning is a serious warning from the Food and Drug Administration (FDA). It alerts patients and doctors about potentially dangerous drug effects.

Enbrel works by weakening certain parts of your immune system. This can make it harder for your body to fight infections. Taking Enbrel can increase your risk for bacterial, fungal, and viral infections, including serious infections such as tuberculosis (TB). Although very rare, these infections can be deadly in certain cases.

If you’ve had TB or the hepatitis B virus (HBV) in the past, Enbrel can also increase your risk for reactivation of these conditions.

In clinical studies, most people who got a serious infection while taking Enbrel were taking other medications that weaken the immune system. These included corticosteroids (such as dexamethasone) or methotrexate (Trexall).

What you can do

Before you start taking Enbrel, your doctor will test you for TB. If this test is positive, you may need TB treatment before you can safely start taking Enbrel. While being treated with Enbrel, you and your doctor should continue to watch for any symptoms of an infection, including TB.

If you develop a serious infection, your doctor may have you temporarily stop taking Enbrel until the infection is treated.

Cancers

Enbrel has a boxed warning about increased risk of certain cancers. A boxed warning is a serious warning from the Food and Drug Administration (FDA). It alerts patients and doctors about potentially dangerous drug effects.

There have been a few reports of new cancers in people taking tumor necrosis factor (TNF) blockers* such as Enbrel. These types of cancers include lymphomas (a type of cancer that affects the lymphatic system) and skin cancer. In rare cases, these have been fatal, including in children and adolescents.

In general, your risk for getting cancer as a side effect from using Enbrel is very low. People who have active rheumatoid arthritis may be at higher risk for developing lymphoma while taking Enbrel, although this rarely occurs.

* TNF blockers are a type of drug that works to reduce inflammation (damage and swelling).

What you can do

Before taking Enbrel, you and your doctor will discuss the pros and cons of using the drug to treat your condition. This will include talking about your risks for certain cancers that may result from Enbrel therapy.

While taking Enbrel, your doctor will monitor you closely for any new cancers. If you have questions about your cancer risk, talk with your doctor.

Allergic reaction

As with most drugs, Enbrel 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 decide whether you should keep taking Enbrel. But if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Below are some precautions to consider before taking Enbrel.

Boxed warnings

This drug has boxed warnings about serious infections and cancers. These are serious warnings 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 Enbrel. 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:

Congestive heart failure. If you have congestive heart failure, taking Enbrel can make symptoms of this condition worse. Talk with your doctor before starting Enbrel. If your doctor determines that Enbrel is safe for you to use, they’ll closely monitor you for any signs that your condition may be worsening.

Diabetes. Enbrel can cause hypoglycemia (low blood sugar) in people who have diabetes. For this reason, your doctor may lower the dosage of any diabetes medications you take when you begin taking Enbrel. This can lower your risk for hypoglycemia.

Neurological conditions, such as multiple sclerosis (MS). Although rare, Enbrel can cause neurological (nervous system) problems. If you already have a neurological condition, such as MS, Enbrel may make your symptoms worse. Make sure to talk with your doctor about the risks and benefits of taking Enbrel.

Moderate or severe alcoholic hepatitis. People with moderate or severe alcoholic hepatitis may have an increased risk of death from taking Enbrel. Be sure to talk with your doctor about the benefits and risks of taking Enbrel if you have this condition.

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

Reactivation of tuberculosis (TB) or hepatitis B virus (HBV). If you’ve had TB or HBV in the past, Enbrel can cause your condition to reactivate. In rare cases, this can be deadly. Your doctor will test you for TB before you begin taking Enbrel. They may also test you for HBV. Be sure to tell your doctor about all of your medical conditions before you take Enbrel.

If you experience reactivation of TB or HBV while you’re taking Enbrel, your doctor will likely recommend stopping Enbrel and treating the infection.

Infections. Enbrel can increase your risk for infections and make it harder for your body to fight them. You should not start taking Enbrel if you have an active infection. Your doctor will want to treat any infections you have before you start taking Enbrel.

Recent live vaccines. People taking Enbrel should not get live vaccines.* If you’ve recently gotten a live vaccine, be sure to tell your doctor. They may have you wait a few days for the vaccine to take effect, and then have you begin taking Enbrel.

* Live vaccines contain a small amount of weakened live virus or bacteria. The chickenpox vaccine and the measles, mumps, and rubella (MMR) vaccine are two examples of live vaccines.

Alcohol use with Enbrel

There aren’t any known interactions between alcohol and Enbrel. However, drinking excessive amounts of alcohol can lead to alcoholic hepatitis. This refers to liver damage and swelling caused by alcohol consumption. People with alcoholic hepatitis may have a higher risk of death from using Enbrel.

If you drink alcohol, talk with your doctor about how much is safe for you to drink while taking Enbrel.

Pregnancy and breastfeeding while taking Enbrel

It’s not known if Enbrel is safe to take while pregnant. Most clinical studies of Enbrel use during pregnancy didn’t show whether the drug was associated with birth defects. Talk with your doctor about the best treatment for your condition if you’re pregnant or planning to become pregnant.

There’s a pregnancy registry for people with certain conditions who use Enbrel while pregnant. This registry collects information about the drug’s use during pregnancy, to help others make decisions about their treatment. Your doctor can provide more information about this registry.

It’s not known if Enbrel is safe to use while breastfeeding. Very small amounts of Enbrel may pass into breast milk. It isn’t known whether this may affect a breastfed child. Talk with your doctor about the best treatment for your condition if you’re breastfeeding or planning to breastfeed.

Although side effects can occur with Enbrel use, most aren’t common. And when they do occur, they’re usually mild. Most mild side effects of the drug go away with time and don’t require medical attention.

You should call your doctor if you experience symptoms of serious side effects, such as:

These side effects could be serious and require medical attention. You should also call your doctor if you become pregnant while taking Enbrel.

If you’d like to learn more about Enbrel, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Note: For more information on arthritis, see our list of rheumatology articles. To learn more about plaque psoriasis, see our list of psoriasis articles.

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 other 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.