Key takeaways

  • Mild side effects of Biktarvy include nausea, skin rash, and fatigue.
  • Biktarvy can also cause serious side effects, such as liver damage or depression.
  • The drug carries a boxed warning about the risk of worsening hepatitis B. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) is used for treating HIV in certain situations. The drug may be prescribed for adults and some children who weigh at least 14 kilograms (about 30.8 pounds).

Keep reading to learn about the common, mild, and serious side effects Biktarvy can cause.

Biktarvy has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see “Side effects explained.”

Some people may experience mild to serious side effects during treatment with Biktarvy. Listed here are some examples of the drug’s commonly reported side effects. But these are not all the possible side effects of Biktarvy.

Some common side effects include:

  • nausea
  • diarrhea
  • headache
  • fatigue (low energy)

These are just a few of the more common side effects studies of Biktarvy have reported.

Biktarvy may cause some mild side effects.

Examples that have been reported with this drug 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 bother you, talk with your doctor or pharmacist. And do not stop taking Biktarvy unless your doctor recommends it.

Biktarvy may cause mild side effects other than those listed here. See the drug’s prescribing information for details.

Biktarvy may cause serious side effects, but they’re usually less common than mild ones.

Serious side effects that have been reported with Biktarvy include:

If you develop serious side effects while taking Biktarvy, 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.

For more information about some of these side effects, see “Side effects explained.”

Note: After the FDA approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Biktarvy and want to tell the FDA about it, visit MedWatch or call 800-332-1088.

Allergic reaction

For some people, Biktarvy can cause an allergic reaction. But this side effect wasn’t reported in the drug’s studies.

Symptoms of an allergic reaction 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 a treatment to manage your symptoms and can determine whether you should keep taking Biktarvy.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty 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’ve had a serious allergic reaction to Biktarvy, they may have you switch to a different treatment.

Biktarvy may cause long-term side effects, but they’re not common.

Long-term side effects include:

Note that Biktarvy has a boxed warning for worsening of hepatitis B. For more information about some of these side effects, including details about Biktarvy’s boxed warning, see “Side effects explained.”

Long-term side effects may begin during treatment with Biktarvy. And in some cases, they may continue after treatment ends.

If you have ongoing side effects while taking Biktarvy, talk with your doctor. They’ll determine whether you need to stop taking it and switch to a different HIV medication.

Do not stop taking Biktarvy without first talking with your doctor. Suddenly stopping this drug can cause serious side effects if you have certain conditions. (See “Side effects explained” for more information.)

Your doctor will monitor you for worsening of certain conditions if you stop taking Biktarvy.

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

Does Biktarvy cause weight gain?

It’s possible. Weight gain wasn’t reported in studies of Biktarvy, but it has been reported since Biktarvy and similar drugs were approved for use.

Biktarvy contains the active ingredients bictegravir (BIC), emtricitabine (FTC), and tenofovir alafenamide (TAF). BIC belongs to a group of drugs called integrase strand transfer inhibitors (INSTIs). FTC and TAF belong to a group of drugs called nucleoside reverse transcriptase inhibitors (NRTIs). It’s possible for INSTIs and NRTIs to cause weight gain.

If you experience weight gain during treatment with Biktarvy, talk with your doctor. They’ll try to determine whether Biktarvy is the cause. They can also suggest ways to manage your weight while taking this drug.

Does Biktarvy cause neuropathy?

No, neuropathy (nerve damage) wasn’t reported in studies of the drug.

Some symptoms of neuropathy include:

  • tingling in your hands or feet
  • difficulty walking (balance or coordination problems)
  • muscle cramps
  • painful burning sensations in your hands or feet

If you experience symptoms of neuropathy, talk with your doctor. They’ll discuss possible causes with you and suggest ways to help manage your symptoms.

Will I have hair loss from Biktarvy?

No, this wasn’t a side effect reported in studies of the drug.

But Biktarvy contains the active ingredients emtricitabine and tenofovir alafenamide. These belong to a group of drugs called NRTIs. And there have been reports of hair loss with NRTIs.

If you have hair loss while taking Biktarvy, talk with your doctor. They’ll suggest ways to help manage this side effect.

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

Boxed warning: Risk of worsening hepatitis B

Biktarvy has a boxed warning for the risk of worsening hepatitis B. A boxed warning is the most serious warning from the FDA.

Biktarvy may lead to a worsening of hepatitis B in some people. You have an increased risk of worsening hepatitis B if you also have HIV and stop taking Biktarvy.

If you have both conditions, your doctor will monitor your liver function for several months if you stop taking Biktarvy. This is to make sure the hepatitis B isn’t worsening. If it is, you may need treatment for it.

For more details on this serious side effect, see the prescribing information or talk with your doctor or pharmacist.

What might help

Your doctor will check whether you have hepatitis B before you begin treatment with Biktarvy. Do not suddenly stop taking Biktarvy if you have both HIV and hepatitis B. This could increase your risk of serious liver damage from worsening hepatitis B.

If you have both HIV and hepatitis B and need to stop taking Biktarvy, your doctor will monitor your liver function for several months after you stop treatment. This is to make sure hepatitis B isn’t worsening.

You may need treatment for hepatitis B if your condition worsens after you stop Biktarvy.

Skin rash

Biktarvy may cause a skin rash in some people, but this wasn’t very common in the drug’s studies.

What might help

If you develop a rash while taking Biktarvy, tell your doctor. If it’s a mild rash, they may recommend an antihistamine such as diphenhydramine (Benadryl). They may also recommend hydrocortisone cream, which you apply to the affected areas of your skin.

But if you have a severe rash, this may be a sign of an allergic reaction to Biktarvy. You should call 911 or go to an emergency medical center immediately if you have this or other symptoms of a severe allergic reaction. These include difficulty breathing and swelling under your skin or in your mouth or throat. (See “Allergic reaction” for more information.)

New or worsening kidney problems

Biktarvy can cause new or worsening kidney problems, including kidney failure in some people. Taking certain other drugs that also affect your kidneys may increase your risk of kidney problems from Biktarvy. Tell your doctor about all the medications you take and whether you have a history of kidney disease.

Symptoms of kidney problems include issues with urination, such as:

What might help

Your doctor will check your kidney function before you start Biktarvy and will monitor it throughout your treatment. If you develop signs of kidney problems, they’ll determine whether this drug is right for you based on the severity of your symptoms. In some cases, they’ll have you stop Biktarvy and will recommend an alternative that’s safer for you.

Lactic acidosis

Biktarvy may cause a serious reaction known as lactic acidosis. This is when your body has too much lactic acid and can’t get rid of it. This can be life threatening in certain cases.

Symptoms of lactic acidosis include:

What might help

Tell your doctor if you have liver or kidney problems. These organs remove Biktarvy from your body. If they’re not functioning properly, lactic acid can build up in your system. This can increase your risk of developing lactic acidosis.

Your doctor will monitor your liver and kidney function before you start Biktarvy and during your treatment. But if you experience symptoms of lactic acidosis, call 911 or your local emergency number immediately.

Keeping track of side effects

During your Biktarvy treatment, consider taking notes on any side effects you’re having. You can then 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 such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • 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 them learn more about how Biktarvy affects you. They can then use this information to adjust your treatment plan if needed.

Here are several warnings about Biktarvy. This drug may not be suitable for you in certain situations. Your doctor will determine whether it’s the right treatment option for you based on your health.

Boxed warning: Risk of worsening hepatitis B

Biktarvy has a boxed warning for the risk of worsening hepatitis B. A boxed warning is the most serious warning from the FDA.

To learn more, see “Side effects explained.”

Other warnings

Biktarvy can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Biktarvy is a good treatment option for you.

Talk with your doctor about your health history before you take Biktarvy. Be sure to tell them if any of the following factors apply to you:

  • liver problems
  • kidney problems
  • alcohol consumption
  • previous allergic reaction to Biktarvy
  • depression or certain mental health conditions
  • suicidal thoughts or behaviors
  • pregnancy
  • breastfeeding

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

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.