Harvoni (ledipasvir/sofosbuvir) is a brand-name drug that’s prescribed for hepatitis C in adults and certain children. As with other drugs, Harvoni can cause side effects, such as irritability and headache.

Harvoni belongs to a drug class called direct-acting antivirals. The drug is available in a generic version, and it comes in the following forms:

  • tablets that you swallow
  • pellets that you swallow alone or after mixing with certain foods

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

Harvoni can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, 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 Harvoni in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

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

Mild side effects that have been reported with Harvoni include:

These side effects may be temporary, lasting a few days to weeks. However, 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 side effects of the medication. If you develop a side effect while taking Harvoni and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after taking Harvoni. However, this side effect wasn’t reported in clinical trials. To learn more, see the “Side effect specifics” section below.

Harvoni may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Harvoni’s prescribing information.

If you develop serious side effects while taking Harvoni, 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 include:

* Harvoni has a boxed warning for this side effect. This is a serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.
† An allergic reaction is possible after taking Harvoni. However, this side effect wasn’t reported in clinical trials. To learn more, see the “Side effect specifics” section below.

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

Does Harvoni cause long-term side effects?

It’s not likely. Long-term side effects weren’t reported in Harvoni’s clinical trials. Most of the drug’s side effects are expected to be temporary. They should last only a few days or weeks after you start or stop taking Harvoni.

If you have questions about how long Harvoni’s side effects could last, talk with your doctor or pharmacist.

Can Harvoni cause weight gain or weight loss?

No, it isn’t likely. Weight gain and weight loss weren’t reported in Harvoni’s clinical trials.

However, weight changes can result from other side effects of Harvoni. These include diarrhea, nausea, and depression. Weight loss can also be a symptom of hepatitis C, which Harvoni is prescribed to treat.

If you have questions about what to expect while taking Harvoni, talk with your doctor.

Learn more about some of the side effects that Harvoni may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Harvoni.

Risk of reactivated hepatitis B

Harvoni has a boxed warning for the risk of reactivated hepatitis B. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It lets doctors and patients know about a drug’s effects that may be dangerous.

With reactivation, the hepatitis B virus becomes active again and causes symptoms of a hepatitis B infection. Examples include loss of appetite, nausea and vomiting, dark urine, and jaundice. In extreme cases, this side effect can be life threatening.

This side effect may occur in people taking Harvoni for hepatitis C who have had a hepatitis B infection in the past. Hepatitis B reactivation is possible during or after stopping Harvoni treatment.

What you can do

Before starting Harvoni treatment, your doctor will run certain tests to see if you have HBV. If you do have HBV, your doctor may treat it before prescribing Harvoni. They’ll likely continue testing your liver function while you’re taking Harvoni and for several months after treatment stops.

If you have symptoms of hepatitis B infection while taking Harvoni or after stopping it, tell your doctor right away.

Dizziness

Dizziness was one of the more common side effects in Harvoni’s clinical trials. With dizziness, you may feel lightheaded or unsteady.

Keep in mind that dizziness can be a symptom of slow heart rate. This side effect may occur when you take Harvoni in combination with amiodarone (Nexterone, Pacerone), which is used to treat an irregular heart rhythm.

What you can do

If you have bothersome or long lasting dizziness during Harvoni treatment, talk with your doctor. They can help determine whether Harvoni or another factor may be the cause.

If you take amiodarone, be sure to talk with your doctor before starting Harvoni treatment. They can tell you whether it’s safe to take these medications together.

Irritability

Irritability was one of the more common side effects in clinical trials of Harvoni. With irritability, you may feel more agitated or annoyed than usual.

Keep in mind that irritability can be a symptom of depression. In clinical trials, depression was a rare but serious side effect of Harvoni.

What you can do

If you feel irritable while taking Harvoni, talk with your doctor. They can help determine whether the drug or another factor, such as depression, could be the cause.

Your doctor can also suggest ways to manage irritability. Examples include meditation, breathing techniques, and a regular sleep or exercise schedule.

Shortness of breath

Shortness of breath was one of the more common side effects in Harvoni’s clinical trials. With shortness of breath, you may have chest tightness or labored breathing.

It’s important to remember that shortness of breath can be a symptom of slow heart rate. This side effect may occur when Harvoni is taken in combination with a heart rhythm drug called amiodarone (Nexterone, Pacerone).

What you can do

If you have shortness of breath while taking Harvoni, talk with your doctor. They can help determine whether Harvoni or another factor may be causing it.

If you take amiodarone, be sure to talk with your doctor before starting Harvoni treatment. They can tell you whether it’s safe to take these medications together.

Allergic reaction

As with most drugs, Harvoni can cause an allergic reaction in some people. However, this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • 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 you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Harvoni. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

Keep reading to learn more about precautions for Harvoni.

Boxed warning: Risk of reactivated hepatitis B

This drug has a boxed warning for the risk of reactivated hepatitis B. This is a serious warning 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 Harvoni. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Kidney problems. Before starting Harvoni treatment, tell your doctor if you have a kidney problem. Especially tell them if you have kidney failure and receive dialysis. Hepatitis C, which Harvoni is used to treat, may cause a condition called decompensated cirrhosis. It isn’t known for certain whether the drug is safe if you have this condition and severe kidney problems. Your doctor can tell you whether Harvoni is a safe treatment option.

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

Alcohol with Harvoni

There are no known interactions between Harvoni and alcohol.

That said, drinking alcohol could worsen hepatitis C, which Harvoni is used to treat. Drinking alcohol could also worsen certain side effects of the drug, such as headache, nausea, and fatigue.

Due to these risks, your doctor may recommend limiting or avoiding alcohol during Harvoni treatment. If you have questions about this, talk with your doctor or pharmacist.

Pregnancy and breastfeeding while taking Harvoni

It’s not known whether Harvoni is safe to take during pregnancy or while breastfeeding. It isn’t known whether the drug may affect a fetus or a child who is breastfed.

However, Harvoni may be prescribed in combination with certain medications that aren’t safe to take during pregnancy. To learn more, see this article.

If you’re pregnant, breastfeeding, or planning for either, talk with your doctor before taking Harvoni.

As with other drugs, Harvoni can cause side effects. Most are mild and should ease over time.

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

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information about Harvoni. For details about other aspects of Harvoni, refer to this article.
  • Cost. If you’d like to learn about Harvoni and cost, see this article.
  • Drug comparison. To learn how Harvoni compares with Epclusa, read this article.
  • A look at your condition. For details about hepatitis C, see this article.

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 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.