Mavyret (glecaprevir/pibrentasvir) is a prescription drug that’s used to treat hepatitis C. Mavyret can cause side effects that range from mild to serious. Examples include headache and fatigue (lack of energy).

Mavyret is used in adults and in children ages 3 years and older to treat:

  • chronic hepatitis C virus (HCV) genotypes 1 through 6 without cirrhosis (scarring of the liver), or with compensated (mild) cirrhosis
  • chronic HCV genotype 1 in those who’ve received treatment with a different type of drug but whose HCV was not cured

The active ingredients in Mavyret are glecaprevir and pibrentasvir. (Active ingredients are what make a drug work.) The drug comes oral tablets and pellets, both of which you swallow.

Keep reading to learn about the common, mild, and serious side effects that Mavyret can cause. For a general overview of the drug, including details about its uses, see this article.

Like all drugs, Mavyret may cause side effects in some people. Common side effects of Mavyret can include:

  • headache
  • fatigue (lack of energy)
  • nausea
  • diarrhea

Learn more about Mavyret’s side effects in the next sections.

Most people who’ve taken Mavyret have had mild side effects. In most cases, these mild side effects are manageable and may go away with time.

Mild side effects of Mavyret can include:

Mavyret may cause other mild side effects, too. See the drug’s prescribing information for more details.

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 Mavyret, visit MedWatch.

* This mild side effect may be a symptom of chronic hepatitis C virus itself. Or it may be a symptom of a serious side effect of Mavyret, such as reactivation of the hepatitis B virus. (See “Side effects explained” below to learn more.)

Mavyret may cause serious side effects in some people. In general, serious side effects from this drug are rare.

Serious side effects can include:

For details on these serious side effects, see the “Side effects explained” section below.

Talk with your doctor about your risk for severe side effects. Call them right away if you experience any new or worsening symptoms. If your symptoms feel life threatening, call 911 or your local emergency phone number, or get emergency medical care.

* Mavyret has a boxed warning for this side effect. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). For more information, see “Side effects explained” below.

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

Are there any interactions between Mavyret and other drugs?

Yes. Mavyret may interact with certain drugs, including:

Other drugs may interact with Mavyret. In addition, Mavyret shouldn’t be taken with the herb St. John’s wort. For more details on Mavyret interactions, see “What should be considered before taking Mavyret?” in this in-depth article.

Before starting Mavyret, talk with your doctor or pharmacist about any vitamins, herbs, and prescription or over-the-counter products you use. They can help determine whether there’s a risk of interaction with Mavyret.

Will I have side effects after stopping Mavyret?

It’s possible. If you’ve had the hepatitis B virus (HBV) in the past, the virus could reactivate (flare up and cause symptoms) during your Mavyret treatment. This could happen even after you’ve stopped taking Mavyret.

If HBV flares up, it can cause serious liver problems, including severe or fatal liver failure.

If you’ve had HBV in the past, tell your doctor before starting Mavyret. They’ll monitor you closely while you’re taking Mavyret. Or they may decide that a different treatment is a better fit for you.

Will taking Mavyret make me feel sick?

It could. Common side effects of Mavyret include nausea, headache, fatigue (lack of energy), and diarrhea. These side effects could make you feel unwell.

While taking Mavyret, talk with your doctor if you feel sick or have side effects that become severe or don’t go away. Certain side effects, including diarrhea and fatigue, could be symptoms of rare but serious side effects, such as reactivated hepatitis B virus. (To learn more, see the “Side effects explained” section below.)

How long do side effects from Mavyret last?

In most cases, mild side effects from Mavyret should only last while you’re taking the drug. Mavyret treatment typically lasts for 8 to 16 weeks, depending on your condition and past treatments. Any mild side effects you experience should go away when you end your Mavyret treatment.

However, Mavyret can cause HBV to reactivate (flare up and cause symptoms) if you’ve had the virus in the past. HBV can cause severe or fatal liver failure, and this side effect can happen during or after your Mavyret treatment. (To learn more about HBV reactivation, see the “Side effects explained” section below.)

If you’re concerned about long-term side effects from Mavyret, talk with your doctor.

Does Mavyret cause hair loss?

No, Mavyret shouldn’t cause hair loss. Hair loss wasn’t seen in studies of Mavyret.

Other medications called interferons may cause hair loss. Interferons used to be the main treatment prescribed for hepatitis C, but newer drugs such as Mavyret are more commonly prescribed now.

If you experience unexplained hair loss while taking Mavyret, talk with your doctor.

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

Reactivation of hepatitis B virus

If you’ve had the hepatitis B virus (HBV) in the past, Mavyret can make HBV reactivate (flare up and cause symptoms). Using Mavyret raises the risk of HBV reactivation in people with both HBV and the hepatitis C virus. If HBV flares up, it could cause serious or fatal liver failure.

Mavyret has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA).

Before starting Mavyret, tell your doctor if you’ve had HBV in the past. They may test you for HBV before you start treatment. If the test is positive, the HBV will need treatment before you start Mavyret. Your doctor may monitor you more closely during and after your Mavyret treatment.

What might help

If you’ve had HBV in the past, tell your doctor. Before starting Mavyret, your doctor may test you for HBV. If the test is positive, the infection will be treated before you start Mavyret. In some cases, your doctor may monitor you closely during and after your Mavyret treatment.

Also, while taking Mavyret, tell your doctor right away if you have any symptoms of worsening hepatitis or liver problems. These symptoms may include:

  • confusion
  • dark urine or stools
  • diarrhea
  • fatigue (lack of energy), or drowsiness
  • reduced appetite
  • nausea or vomiting, especially vomiting blood
  • pain, or swelling, in your upper-right abdomen
  • unusual bleeding or bruising
  • jaundice (yellowing of the skin or the whites of your eyes)

Itching

While taking Mavyret, you may experience itching. In studies, itching was a common side effect in certain groups of people using Mavyret. This included people with severe liver or kidney problems and people who had received a kidney or liver transplant.

Itching can also be a symptom of both hepatitis C virus (HCV) and hepatitis B virus (HBV).

Itching during your Mavyret treatment may be a symptom of your HCV infection. It could be a symptom of reactivated HBV, if you’ve had the virus before. Reactivated HBV is a serious side effect of Mavyret. (See “Side effects explained” below to learn more.)

What might help

If you have itching that bothers you or becomes severe, talk with your doctor. They may prescribe treatment to help relieve your symptoms.

If your itching is mild, try these tips:

  • Apply cool compresses to itchy areas.
  • Take cool showers or baths.
  • Wear loose cotton clothing.
  • Try not to scratch.
  • Apply calamine lotion.

Fatigue

You may experience fatigue (lack of energy) while taking Mavyret. This is a common side effect of the drug.

Fatigue is also a common symptom of active chronic hepatitis C virus (HCV). When a virus is “active,” that means it’s currently causing symptoms.

Fatigue may occur with HCV because your body is fighting the virus. Some studies suggest fatigue happens because HCV damages your liver. It’s thought that liver damage causes issues with messages in your brain that tell your body about its energy levels.

In addition, fatigue may be a symptom of depression. People with HCV may have a higher risk for depression. If you think you may have untreated depression or another mental health condition, talk with your doctor right away.

What might help

If you have fatigue that affects your daily life, talk with your doctor. Keep in mind that if you’ve had hepatitis B virus (HBV), taking Mavyret can make the virus reactivate (flare up and cause symptoms).

Fatigue can be a side effect of HBV. Call your doctor right away if you have severe fatigue, or fatigue with other HBV symptoms. (See “Reactivation of hepatitis B virus” above to learn about HBV symptoms.)

Mavyret isn’t a long-term treatment. If your fatigue is mild, you may be able to manage it during your treatment without having to switch medications. Try these tips to help boost your energy:

  • Take short naps when possible.
  • Drink plenty of water each day.
  • Eat a well-balanced diet.
  • Stick to a regular sleep schedule.
  • Stretch, do yoga, or take short, brisk walks (if your doctor recommends this).
  • Reduce your caffeine intake.

Headache

You may experience headache while taking Mavyret. This is a common side effect of the drug.

What might help

While taking Mavyret, talk with your doctor if you have headaches that disrupt your daily life or your sleep.

Talk with your doctor before using any over-the-counter pain relievers to treat your headache. Some products contain acetaminophen, which can harm your liver. You should avoid acetaminophen while taking Mavyret. This is because Mavyret is used in people with chronic hepatitis C virus, which is a liver infection.

If your headaches are mild, try these natural ways to manage them:

  • Place a wrapped cold pack on your forehead for 15 minutes.
  • If heat feels better, take a warm bath.
  • Lie down in a dark, quiet place.
  • Try a meditation app, or breathing exercises.

Allergic reaction

Like most drugs, Mavyret can cause an allergic reaction in some people. Symptoms can be mild or serious, and can include:

  • rash
  • flushing (warmth, swelling, or redness in your skin)
  • 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 a treatment to manage your symptoms. Examples include:

  • an antihistamine you swallow, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you had a mild allergic reaction to Mavyret, 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 may be life threatening, and may require immediate medical care.

Keeping track of side effects

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

Your side effect notes can include things like:

  • 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 Mavyret affects you. Your doctor can use this information to adjust your treatment plan if needed.

Mavyret has several warnings that may affect your ability to safely use this drug. See below.

Boxed warning: Reactivation of hepatitis B virus

Mavyret has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA).

Reactivation of hepatitis B virus. If you’ve had the hepatitis B virus (HBV) in the past, using Mavyret can cause HBV to reactivate (flare up). In rare cases, this flare-up could cause serious or fatal liver failure. Before starting Mavyret, tell your doctor if you’ve had HBV in the past.

For more information on this warning, see the “Side effects explained” section above.

Other warnings

Mavyret 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 take Mavyret. Factors to consider include those in the list below.

Liver disease. If you have moderate to severe liver disease in addition to the hepatitis C virus, using Mavyret may worsen your liver disease. This includes raising your risk for fatal liver failure. Before starting Mavyret, tell your doctor if you currently have liver disease or have had it in the past.

Rifampin or atazanavir use. You shouldn’t take Mavyret if you use the HIV antiviral drug atazanavir (Reyataz). Using these drugs together may increase your level of a certain liver enzyme (protein). Mavyret also shouldn’t be used with the antibiotic rifampin (Rifadin). Using these drugs together may lower the level of Mavyret in your body, making it less effective.

Allergic reaction. If you’ve had an allergic reaction to Mavyret or any of its ingredients, you shouldn’t take Mavyret. Ask your doctor what other medications are better options for you.

Alcohol and Mavyret

Although Mavyret doesn’t interact with alcohol, it’s used in people with chronic HCV. If you have HCV, you shouldn’t drink alcohol. Alcohol can make HCV worse, which can lead to cirrhosis (severe scarring) in your liver.

If you drink alcohol and are concerned about how to stop drinking, talk with your doctor.

Pregnancy and breastfeeding while taking Mavyret

It’s unknown if Mavyret is safe to take during pregnancy or while breastfeeding.

To learn if Mavyret is right for you, talk with your doctor if you’re:

  • pregnant
  • planning to become pregnant
  • would like to breastfeed your child

Taking Mavyret may cure your chronic hepatitis C virus (HCV). It may also cause side effects. In general, most side effects of this drug are mild.

If you have questions about Mavyret’s side effects, talk with your doctor or pharmacist. They can provide answers to help you feel confident about your HCV treatment.

Ask about any of your concerns, such as:

  • Do I have a high risk for side effects with Mavyret?
  • How will I know if Mavyret will reactivate my hepatitis B?
  • Does having HIV raise my risk for side effects with Mavyret?
  • What could happen if I take a statin with Mavyret?
  • If I have mild diarrhea during treatment, how should I manage it?

To learn more about Mavyret, see these articles:

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Q:

I have mild itching with Mavyret. My doctor suggested an over-the-counter (OTC) anti-itch cream to soothe this side effect. Can you recommend a product?

Anonymous

A:

Before using any OTC anti-itch products, talk with your doctor or pharmacist. Specifically, you should ask them if it will interact with any medications or supplements you already take. You should also ask whether your medical history makes one or more of these products unsafe for you to take.

If you experience mild itching with Mavyret, your doctor may recommend an OTC anti-itch cream to treat this side effect. Examples include:

  • products containing benzocaine, such as Lanacane Maximum Strength anti-itch cream
  • products containing lidocaine, such as Gold Bond Multi-Symptom with 4% lidocaine
  • an antihistamine taken by mouth, such as diphenhydramine (Benadryl) or loratadine (Claritin)
  • calamine lotion
  • colloidal oatmeal

It’s important to note that although these are OTC products, that doesn’t make them safe for everyone to use. Discuss your treatment options with your doctor or pharmacist. They can help choose the safest option for you.

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

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 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.