FAQ About Emtricitabine and Tenofovir Disoproxil Fumarate (Truvada)

Written by Kendall K. Morgan
Medically Reviewed by Jonathan E. Kaplan, MD on April 25, 2025
5 min read

Has your doctor suggested you take emtricitabine/tenofovir disoproxil fumarate (Truvada)? Or are you curious about whether it might be a good idea for you or a loved one to take it? Get answers to some common questions you may have about this medication.

Emtricitabine and tenofovir disoproxil fumarate (Truvada) is a prescription medicine used to treat or prevent HIV. This drug’s name is so long because it combines two antiviral drugs into one tablet.

One of them is emtricitabine, an antiviral drug used to treat HIV infection in people of all ages. While it can’t cure HIV, it can slow down the virus’s progress.

Tenofovir disoproxil fumarate, or tenofovir DF, is the other drug in the combination. It’s also an antiviral, used to treat HIV infection in adults and kids as young as 2. (On its own, it’s also prescribed to treat hepatitis B, but the combination drug isn’t meant for that condition.)

When it’s used to treat an HIV infection, doctors always prescribe emtricitabine/tenofovir disoproxil fumarate along with other HIV medicines. But when they prescribe it to reduce your risk of infection (for PrEP, or preexposure prophylaxis), you take it by itself.

If you already have HIV, you can take this medication along with other antiviral drugs to control the infection. It reduces the amount of the virus in your system. This helps keep you from developing AIDS (acquired immunodeficiency syndrome) and complications related to it, like cancer and serious infections. Also, when you have lower levels of HIV in your blood, you’re less likely to pass it to someone else.

Doctors can also prescribe this drug to help keep you from getting an HIV infection in the first place. It can stop the virus from establishing itself in your body.

People who have an HIV infection can take this medication along with other drugs to stop the virus from getting worse and causing health problems. It’s approved to treat HIV in adults and children weighing at least 37 pounds.

You can also take it for PrEP if a doctor has confirmed you’re HIV-negative, but you know you’re at high risk for infection. For instance, you might take it if you don’t always practice safe sex, if your sexual partner has HIV, or if you or your partner has injected drugs in the past 6 months. It doesn’t guarantee you won’t get the virus, so you should still take other steps to prevent HIV and other sexually transmitted diseases, such as using condoms. 

You can use emtricitabine/tenofovir to help prevent HIV if you're an adult or a child weighing over 77 pounds.

This drug isn’t right for everyone. Don’t take it if you’re allergic to emtricitabine, tenofovir disoproxil fumarate, or any of their ingredients. (Your pharmacist can give you an ingredient list.) And never use it by itself for PrEP if you’re not sure about your HIV status. 

In some other cases, your doctor will need to weigh the risks and benefits of taking this drug. Tell your doctor if you:

  • Have a condition that affects your liver, such as hepatitis B
  • Have kidney problems or kidney disease
  • Have bone problems, like a broken bone or bone density issues 
  • Are pregnant, or breastfeeding, or plan to be 

Emtricitabine/tenofovir disoproxil fumarate is generally thought to be safe while you’re pregnant or nursing. Your doctor may advise against breastfeeding if you have HIV.

If your doctor has suggested you take this medicine but you’re not sure if you should, tell them your concerns.

HIV is a virus that attacks your immune cells. Both of the medicines in emtricitabine/tenofovir disoproxil fumarate block pathways that the virus uses to multiply.

When HIV infects a cell, it tries to make copies of itself. To do that, it uses an enzyme called reverse transcriptase. This medication blocks the enzyme, which keeps the virus from multiplying.

The two medicines in this combination medication belong to the same drug class. They’re called nucleoside reverse transcriptase inhibitors (NRTIs) because they block the reverse transcriptase enzyme.

The two medicines in this drug keep HIV from multiplying. If you take it before you have an infection, it can make it a lot harder for HIV to stay in your body. So it can keep you from getting infected even when you’re exposed to the virus. 

Keep in mind that it doesn’t always work. That’s why you should still take other steps to protect yourself from HIV as well as other sexually transmitted diseases.

Always take this medication exactly as your doctor prescribes. You usually take one tablet daily. Try to take it about the same time every day. You can take it with food or without. 

If you have questions or concerns about the medicine, ask your doctor or pharmacist for help. Don’t skip doses or stop taking it without talking to your doctor first. If you accidentally miss a dose, you can take it later the same day. But don’t take more than one dose a day.

For people who take the drug to treat HIV, the most common side effects are:

  • Diarrhea
  • Nausea
  • Tiredness
  • Headaches
  • Dizziness
  • Depression
  • Trouble sleeping
  • Strange dreams
  • A rash

For those who take it to reduce the chances of getting HIV, the most common side effects include:

  • Headaches
  • Stomach or belly pain
  • Weight loss

Often, these side effects will go away within a few weeks as your body gets used to the drug.

More serious side effects may include:

  • Kidney problems or kidney failure
  • Immune system symptoms, like a fever or swollen lymph nodes 
  • Bone problems, such as pain, softening, thinning, or fractures
  • Weakness, pain, or shortness of breath (from high levels of lactic acid, a chemical your body makes)
  • Yellow skin or eyes, dark urine, appetite loss, or other symptoms related to serious liver problems
  • You should not stop this medicine if you have hepatitis B, unless carefully supervised by your doctor

Call your doctor right away if you notice any new or worrying symptoms.

The retail (before-insurance) price for a 30-day supply of the brand-name medication Truvada is nearly $2,000, according to drugs.com. But you might pay $30 or less for the generic version. Health insurance often covers the drug, whether you take it to treat HIV or to reduce your chances of infection. 

If you don’t have coverage through a government or private health insurance plan, look for discounts, coupons, or patient assistance programs to help you cover the cost.

The company that makes Truvada offers financial and insurance support programs. If you’re worried about paying for your HIV medicines, you can also ask your health care team where to get help.

There is a generic version of this drug, and it costs a lot less than the brand-name medication.

The generic has some differences. For example, the tenofovir part of the combination is formulated differently. The box and tablets also may look different. But the generic works the same way as the branded drug. You use it the same way, too.

If you take Truvada and want to switch, ask your doctor or pharmacist if the generic version might be right for you. 

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