If you have certain types of eczema, asthma, or sinusitis, your doctor might suggest Dupixent (dupilumab) as a treatment option for you. Along with other questions you may have about the drug, you could be wondering about its side effects.

Dupixent is a prescription medication that’s used to treat the following conditions in adults and certain children:

  • moderate to severe eczema that’s not responding well to or can’t be treated with prescription medications applied to the skin
  • moderate to severe asthma that’s eosinophilic (involves high levels of white blood cells called eosinophils) or needs regular treatment with corticosteroids taken by mouth

Dupixent is also used in adults to treat:

Dupixent is a biologic medication, which means it’s made using living cells. It treats the conditions listed above by helping to reduce inflammation.

You’ll receive Dupixent by an injection under your skin. Your doctor can teach you how to give yourself the injections at home. If Dupixent works for you without causing troublesome side effects, you’ll likely use it long term.

For more information about Dupixent, including details about its uses, see this in-depth article.

Like other drugs, Dupixent can cause mild or serious side effects. Knowing more about these can help you decide if this treatment may be a good option for you. Keep reading to learn more about Dupixent’s side effects.

Some people may experience mild or serious side effects during their Dupixent treatment. Examples of Dupixent’s more commonly reported side effects include:

* To learn more about this side effect, see “Side effects explained” below.
† To learn more about this side effect, see “Eye-related side effects” under “Side effects explained” below.

Examples of mild side effects that have been reported with Dupixent include:

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

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And do not stop using Dupixent unless your doctor recommends it.

The list above doesn’t include all side effects of Dupixent. For more information on the drug’s side effects, see the Dupixent patient information.

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

Serious side effects that have been reported with Dupixent include:

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

If you develop serious side effects during Dupixent treatment, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Here are the answers to some frequently asked questions about Dupixent’s side effects.

Is weight gain a side effect of Dupixent?

No, weight gain isn’t a known side effect of Dupixent. It wasn’t reported in studies of the drug.

However, weight gain is a common side effect of steroid medications taken by mouth. These are often used to treat severe eczema, asthma, and rhinosinusitis, which Dupixent also treats.

If you’re concerned about weight gain with the medications you take, talk with your doctor. They can suggest ways to maintain a healthy weight.

Can Dupixent cause hair loss?

No, Dupixent isn’t known to cause hair loss. This side effect wasn’t reported in studies of this medication. In fact, Dupixent is under study to see if it can help with hair growth in people who have alopecia areata.

Alopecia areata is a condition that causes hair to fall out in round patches. It can lead to total hair loss on the scalp or other parts of the body.

This condition occurs when a person’s immune system attacks their hair follicles by mistake. Dupixent works on an immune system protein that may be involved in alopecia areata.

How long do Dupixent’s side effects last? Are any long term?

Most mild side effects of Dupixent should get better on their own within a few days or a couple of weeks. But some may need treatment to help them clear up. If you have side effects that last longer than a couple of weeks despite treatment, talk with your doctor.

Some serious side effects of Dupixent, such as keratitis (inflammation of the cornea), may last a long time, even with treatment. Exactly how long side effects last will depend on how they respond to any treatments you may use for them.

If you have questions or concerns about how long Dupixent’s side effects may last, talk with your doctor.

Will using Dupixent give you headaches or make you feel fatigued?

Headaches and fatigue weren’t reported in studies of Dupixent. But that’s not to say these side effects won’t happen with this drug. These are common side effects that can be caused by many medications. And they’re also a common problem in people with long-term conditions.

If you have troublesome headaches or fatigue during Dupixent treatment, talk with your doctor. They can look for the cause and recommend ways to manage the problem.

Can using Dupixent increase your risk for cancer?

No, that’s not likely. Studies haven’t found any increased risk of cancer in people who receive Dupixent.

There is an increased risk of cancer with certain immunosuppressant medications used to treat severe eczema or asthma. Immunosuppressants weaken your immune system, which is your body’s defense against disease. These medications can reduce your body’s ability to find and kill cancerous cells.

But Dupixent doesn’t weaken your entire immune system. It only affects a couple of immune system proteins. So it’s unlikely to affect your body’s ability to find and destroy cancerous cells.

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

Joint pain

Some people may have joint pain while receiving Dupixent. But in studies, this side effect was reported only in people who took Dupixent for rhinosinusitis with nasal polyps.* And it wasn’t particularly common.

* Rhinosinusitis is swelling in the nasal passages and sinuses. Nasal polyps are noncancerous growths in the nose.

What might help

If you have joint pain while receiving Dupixent, talk with your doctor or pharmacist about ways to manage this. For example, some of the following remedies may help:

  • applying hot or cold packs to affected joints
  • getting gentle exercise, such as swimming
  • practicing relaxation techniques, such as meditation or breathing exercises

If you have troublesome joint pain, ask your pharmacist to recommend an over-the-counter pain reliever. Examples include Tylenol (acetaminophen) and anti-inflammatory gels, such as Voltaren (diclofenac). However, if you have asthma, avoid taking oral anti-inflammatories such as Advil (ibuprofen). (“Oral” means taken by mouth.)

Eye-related side effects

Dupixent commonly causes ocular (eye-related) side effects. These side effects can be mild or serious.

Mild eye-related side effects that have been reported with Dupixent include:

Serious eye-related side effects that have been reported with Dupixent include:

If keratitis isn’t treated, it can damage your eyesight or cause other problems, such as corneal ulcers.

In studies, eye-related side effects were more common in people who took Dupixent for eczema than for other uses. Conjunctivitis was reported more often than other eye-related side effects.

Symptoms of eye-related side effects may include:

What might help

If you wear contact lenses or have any current eye problems, talk with your doctor before starting Dupixent treatment. They can advise you as to whether Dupixent is right for you. They can also suggest ways to help avoid eye-related side effects.

During Dupixent treatment, see your doctor right away if you have eye-related symptoms or any new or worsening eye problems. Your doctor will check your eyes and recommend a suitable treatment, depending on the symptoms you have.

Eosinophilic conditions

Dupixent can sometimes increase the number of eosinophils in your blood. Eosinophils are a type of white blood cell.

If you have too many eosinophils (a condition called eosinophilia), this can sometimes cause inflammatory conditions. Examples of these include pneumonia (a lung condition) and vasculitis (inflammation of blood vessels).

Although rare, in early studies of Dupixent, these conditions were reported in people who took the drug to treat asthma. The conditions may have been related to people taking a lower dosage of oral steroid medications as Dupixent eased their asthma symptoms. (“Oral” means taken by mouth.) But it’s not known for sure if these conditions were caused by Dupixent.

Symptoms of these eosinophilic conditions may include:

  • skin rash
  • worsening shortness of breath
  • chest pain
  • fever
  • sensations of tingling, prickling or numbness in the arms or legs

What might help

If you have symptoms of eosinophilic conditions, see your doctor right away. Your doctor will look into the cause of your symptoms and may prescribe treatment if needed.

If you’re taking an oral steroid medication, do not reduce your dose or stop taking it unless your doctor recommends it.

Injection site reactions

You may have injection site reactions during Dupixent treatment. In studies, this was the most common side effect reported in people who received Dupixent for any condition. It occurred most often with the initial dose of the drug.

Injection site reactions may cause the following symptoms in the area where you have a Dupixent injection:

  • redness or change in skin color
  • pain
  • bruising
  • swelling
  • itching

Injection site reactions are usually mild and get better within a few days.

What might help

To help avoid injection site reactions, inject into a different area each time you give yourself a dose of Dupixent. This is called rotating injection sites. Make a note of the date and the site you use each time as a reminder.

Avoid injecting into areas of skin that are tender, bruised, damaged, or scarred. And don’t rub the injection site after the injection.

If you have an injection site reaction that’s causing discomfort, it may help to apply a cold pack to the area. Contact your doctor if you have a reaction that’s severe or doesn’t get better.

Allergic reaction

Like most drugs, Dupixent can cause an allergic reaction in some people.

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. To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine). Or they may recommend a product you apply to your skin, such as hydrocortisone cream.

If your doctor confirms you had a mild allergic reaction to Dupixent, they’ll decide if you should continue using 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 Dupixent, they may have you switch to a different treatment.

Keeping track of side effects

During your Dupixent 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 from the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help your doctor learn more about how a drug affects you. And your doctor can use this information to adjust your treatment plan if needed.

Dupixent 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 you start Dupixent treatment. The list below includes factors to consider.

Allergic reaction. If you’ve had an allergic reaction to Dupixent or any of its ingredients, you should not receive Dupixent. Ask your doctor what other medications are better options for you.

Parasitic infections. If you have a parasitic infection, such as a tapeworm infection, it should be treated before you start Dupixent. If you develop a parasitic infection during Dupixent treatment, contact your doctor. It’s possible to treat the infection while you’re still receiving Dupixent. But if the infection doesn’t go away, you may need to stop Dupixent until the infection clears up.

Vaccines. Dupixent can weaken part of your immune system. As a result, you should not get live vaccines while you’re receiving Dupixent because they could cause infections. (A live vaccine contains a weakened form of the germ the vaccine is designed to protect against.)

Examples of live vaccines include measles, mumps, and rubella (MMR), typhoid, yellow fever, chickenpox, rotavirus, and the nasal spray flu vaccine. (The injected flu vaccine is not a live vaccine.)

Before you start Dupixent treatment, it’s best to catch up on your vaccinations. Talk with your doctor about any vaccinations you may need before starting treatment.

Asthma attacks. Do not use Dupixent to treat an asthma attack or breathing problems. This medication helps to reduce the number and severity of asthma attacks you may have. But it won’t work to relieve an asthma attack.

Alcohol use and Dupixent

Alcohol isn’t known to interact with Dupixent or affect your risk for side effects. If you’re concerned about drinking alcohol while you’re receiving Dupixent, talk with your doctor.

Pregnancy and breastfeeding while receiving Dupixent

It’s not known if Dupixent is safe to use during pregnancy. It’s also not known if Dupixent passes into breast milk or if it can cause side effects in a breastfed child.

If you’re pregnant or planning to become pregnant, talk with your doctor about the possible risks and benefits of receiving Dupixent. And let them know if you’re breastfeeding or planning to breastfeed.

Dupixent has some common side effects, but these are usually mild and easily managed. There aren’t many serious side effects associated with this medication.

If you’d like to know more about the possible side effects of Dupixent, talk with your doctor. They can help you decide if this medication is a good option for you.

Examples of questions you might like to ask include:

  • Can stopping Dupixent treatment lead to side effects?
  • How can I prevent eye-related side effects with Dupixent?
  • Can Dupixent make asthma worse?
  • Do I need to get any vaccines before starting Dupixent?

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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.