How does Truvada work to prevent HIV?

Truvada is made up of two antiviral medications, emtricitabine and tenofovir disoproxil fumarate. It works to lower the risk of human immunodeficiency virus (HIV) infection by blocking pathways the virus uses to infect you and spread in your body. In order to be effective, the medication must be present in your body during an HIV exposure to stop the virus from working to infect your cells.

Truvada is one of a few different medications used for pre-exposure prophylaxis (PrEP). PrEP is medication that people who are at risk of getting HIV take to prevent getting HIV infection from injection drugs or sex. Since Truvada is not 100% effective by itself in preventing HIV infection, it is important to use other measures to protect yourself from HIV as well.

What is the mechanism of action of Truvada?

Both antiviral medications in Truvada (emtricitabine and tenofovir disoproxil fumarate) are nucleoside analog reverse transcriptase inhibitors (NRTIs). NRTIs block a protein called reverse transcriptase that the virus uses to convert its RNA to DNA, which is then usually inserted into the host cell’s DNA. This stops the virus from multiplying and infecting other cells in your body.

Related questions

• Descovy vs Truvada: How do they compare for HIV / PrEP?
• How long does it take for Truvada to work?
• What is the recreational use of ART, including Truvada?

What is the dose of Truvada for PrEP?

When taken for PrEP, one tablet of Truvada (containing 200 mg of emtricitabine and 300 mg of tenofovir) should be taken by mouth once every day. It’s available as an oral tablet that combines two antiviral medications for convenience. Truvada works best when it is taken consistently. Missing doses can cause it to be less effective for preventing an HIV infection.

This is not all the information you need to know about Truvada (tenofovir disoproxil fumarate and emtricitabine) for safe and effective use and does not take the place of your healthcare provider's directions. Review the full product information and discuss this information and any questions you have with your doctor or other healthcare provider.