As with other drugs, Descovy (emtricitabine/tenofovir alafenamide) can cause side effects, such as liver or kidney problems. If you are not able to tolerate side effects of Descovy, talk with your doctor or pharmacist.

Descovy is a brand-name oral tablet prescribed for HIV and to decrease the risk of contracting HIV.

Descovy has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see “Side effect specifics.”

For additional information about Descovy, including details about its uses, see this Descovy overview article.

Descovy 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. 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 Descovy in clinical trials:

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

Mild side effects that have been reported with Descovy include:

  • abdominal pain
  • fatigue
  • diarrhea
  • headache
  • nausea (see “Side effect specifics”)

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. Sharing your experience helps make medications 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 Descovy and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Descovy may cause serious or long-term side effects. The following list may not include all possible serious side effects of the drug. For more information, you can refer to Descovy’s prescribing information.

If you develop serious side effects while taking Descovy, 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.

Serious side effects and their symptoms can include:

  • Liver damage, which may include symptoms such as:
  • Kidney problems, which may include symptoms such as:
    • fatigue
    • nausea and vomiting
    • urinating less often than is typical
  • Lactic acidosis
  • Immune reconstitution syndrome
  • Worsening of hepatitis B
  • Resistance to Descovy treatment

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

Allergic reaction

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

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Descovy, your doctor may recommend taking a different medication instead.

This drug has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Worsening of hepatitis B

This side effect is possible if you have hepatitis B and you stop taking Descovy. Hepatitis B that gets worse can cause severe symptoms, such as liver failure.

Worsening of hepatitis B has been reported in people who stop taking drugs that contain emtricitabine, tenofovir disoproxil fumarate, or both. Descovy contains the active drug emtricitabine and a form of tenofovir called tenofovir alafenamide.

What you can do

Before you start treatment with Descovy, your doctor will order a test to determine whether you have hepatitis B. If you have hepatitis B, your doctor may treat it before having you start Descovy.

It’s important to avoid running out of Descovy tablets. You also should not stop taking Descovy unless your doctor tells you to do so. Stopping Descovy could cause serious side effects in people with hepatitis B.

If you have hepatitis and your doctor decides to have you stop taking Descovy, they’ll monitor you for several months. This will include ordering liver function tests to help make sure your hepatitis B doesn’t get worse. If your hepatitis B does get worse, your doctor may have you take medications to treat it.

If you don’t have hepatitis B, your doctor may recommend getting the hepatitis B vaccine before you start taking Descovy.

If you have questions about hepatitis B and Descovy, talk with your doctor.

Resistance to Descovy treatment

Descovy has a boxed warning about resistance to the drug when used as preexposure prophylaxis (PrEP) for HIV.

Resistance means that Descovy will be less effective at treating HIV, or it may no longer be effective at all. PrEP treatment refers to taking an HIV medication to decrease the risk of contracting the virus.

For this reason, only people who don’t have HIV should take Descovy for PrEP. If you take Descovy for PrEP and you already have HIV, the virus may become resistant to the drug.

What you can do

Before you start taking Descovy for HIV PrEP, your doctor will order a blood test to check for HIV. While you’re taking Descovy, you’ll need to have this test at least every 3 months. If you have or develop HIV, your doctor will recommend a treatment other than Descovy for you.

If you have questions about Descovy for PrEP, talk with your doctor.

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

What are the side effects of using Descovy for PrEP?

PrEP for HIV refers to taking an HIV medication to lower the risk of contracting the virus. Descovy is approved for use as PrEP and HIV treatment.

Descovy for PrEP has the same side effects as Descovy for HIV with the exception of immune reconstitution syndrome, which is only seen in people with HIV.

If you have additional questions about Descovy’s side effects, talk with your doctor or pharmacist. You may also view the prescribing information for more information.

Is weight loss or loss of body fat a side effect of Descovy?

No. Neither weight loss nor loss of body fat were reported as a side effect in clinical trials of Descovy.

Weight loss, however, has been associated with HIV, which Descovy is used to treat. If you experience weight loss, talk with your doctor. They can work with you to help you manage your body weight.

Can Descovy cause vomiting?

Possibly. In clinical trials, people who took Descovy didn’t report vomiting as a side effect. However, vomiting can be a symptom of serious side effects of Descovy, including:

  • new or worsening kidney damage
  • liver damage
  • lactic acidosis (lactic acid buildup in the body)

If you’re taking Descovy for PrEP, vomiting may also be a symptom of recently contracted HIV.

Call your doctor right away if you develop vomiting while taking Descovy. Your doctor can work to determine the cause and recommend the best treatment for you. This may include using an HIV medication other than Descovy.

Is depression a side effect of Descovy?

No. Depression wasn’t reported as a side effect of Descovy in clinical trials.

That said, mental health conditions have been associated with HIV. And depression is one of the most common mental health conditions that people with HIV experience.

Other drugs used to treat HIV, such as emtricitabine/tenofovir disoproxil fumarate (Truvada), can cause depression as a side effect. (For more information about the differences between Descovy and Truvada, read the Descovy vs. Truvada article.)

If you have questions or concerns about your mental health, talk with your doctor. They can help connect you with mental health resources, such as counseling.

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

Nausea

Nausea was one of the most common side effects reported in clinical trials of Descovy.

Usually, nausea caused by Descovy isn’t severe. However, nausea can be a symptom of more serious side effects of Descovy. These side effects include liver damage and lactic acidosis.

What you can do

Call your doctor if you experience nausea while taking Descovy. Your doctor may examine you to determine whether your nausea is a sign of a more serious side effect.

Immune reconstitution syndrome

Immune reconstitution syndrome is a possible side effect of Descovy when the drug is taken to treat HIV. This condition may also be called immune reconstitution inflammatory syndrome (IRIS).

HIV weakens the immune system over time. With IRIS, your immune system gets stronger after starting HIV treatment. This can reduce HIV symptoms. It can also lead to:

  • Symptoms caused by your immune system reacting to infections that may already be present in your body. These symptoms may develop unexpectedly due to a previously undiagnosed infection. Or they may be from a previously treated infection.
  • Certain autoimmune diseases, such as Graves’ disease. With autoimmune diseases, your body’s immune system mistakenly attacks your own cells and organs.

IRIS wasn’t reported in clinical trials of Descovy. However, it has been reported in people with HIV who took medications that contain emtricitabine. Emtricitabine is one of the active drugs in Descovy. (Tenofovir alafenamide is the other active drug.)

Keep in mind that Descovy may cause IRIS only when used to treat HIV. People taking Descovy for HIV for PrEP aren’t likely to develop IRIS, because they don’t have a weakened immune system caused by HIV. PrEP treatment refers to taking an HIV medication to decrease the risk of contracting the virus.

What you can do

While taking Descovy to treat HIV, watch for symptoms of IRIS. This side effect is most likely to occur when you first start treatment with Descovy. Symptoms vary depending on the condition that develops, such as:

Call your doctor right away if you notice any new symptoms when you start taking Descovy.

Lactic acidosis

Lactic acidosis is a very rare but serious side effect of Descovy. With this condition, there’s a buildup of lactic acid in your body. This is a medical emergency that could lead to hospitalization or, if untreated, death.

Lactic acidosis may develop very quickly, within minutes or hours. Or it may develop gradually over a few days. Symptoms may include:

  • atypical or fast heart rate
  • trouble breathing
  • abdominal pain or discomfort
  • muscle pain
  • nausea and vomiting

Certain HIV medications, such as emtricitabine, can make it harder for your body to get rid of lactic acid. This increases your risk of lactic acidosis. Emtricitabine is one of the active drugs in Descovy. (Tenofovir alafenamide is the other active drug.)

What you can do

If you notice symptoms of lactic acidosis, stop taking Descovy right away. If your symptoms are mild, talk with your doctor as soon as possible. If your symptoms develop rapidly or are severe, call 911 or your local emergency number immediately. Or go to your nearest emergency room.

If you develop lactic acidosis while taking Descovy, your doctor will have you stop taking the drug until they can determine what exactly caused this side effect. They may have you switch to a medication other than Descovy, even after your lactic acidosis is treated.

Take note of the following important information to consider before taking Descovy.

This drug has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Boxed warnings for Descovy” section.

Other precautions

  • liver problems
  • kidney problems
  • previous allergic reaction to this or a similar drug
  • pregnancy
  • breastfeeding
  • alcohol consumption

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.