Couple smiling and hugging after using Truvada® effectively in preventing HIV

How effective is Truvada® in preventing HIV?

Written on May 22, 2023 by Gillian (Gigi) Singer, MPH, Sexuality Educator & Certified Sexologist. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

Understanding Truvada®

Truvada® is a combination of two antiretroviral drugs (ARTs), tenofovir disoproxil fumarate (TDF) and emtricitabine, commonly used in the treatment of HIV and as a prophylactic. When taken as PrEP, it can be highly effective in preventing HIV acquisition. Pre-exposure prophylaxis (PrEP) is a class of medication that provides protection against the transmission of Human Immunodeficiency Virus (HIV) in instances of potential exposure to the virus.

Truvada® is an oral medication available in pill form, recommended for individuals at risk of HIV transmission through sexual activity or injection drug use. As part of the prescribed regimen, Truvada® is taken once daily to provide effective prevention against HIV infection.[1]

Truvada® works by hindering key enzymes’ ability to replicate so as to reduce the risk of infection. Read on to learn the answer to the question “How effective is Truvada® in preventing HIV?”

Clinical studies and effectiveness

Several clinical trials have evaluated the effectiveness of Truvada® as PrEP. One important study demonstrated a significant reduction in HIV transmission among high-risk individuals. The study reported an overall reduction of 44% in HIV acquisition among men who have sex with men, with a 92% reduction observed among those who adhered closely to the treatment plan that was prescribed to them.[2]

Moreover, the results of the Partners PrEP study, which involved heterosexual couples, revealed a 75% reduction in HIV transmission when the HIV-negative partner consistently took Truvada®.[3] These studies collectively emphasize the effectiveness of Truvada® when used consistently and correctly.

Comparing efficacy with other PrEP methods

A trial showed that 99.7% of people taking Descovy® for PrEP in the trial stayed HIV-negative and that it is just as effective as Truvada®.[4]

Another trial demonstrated that participants who took Apretude® had 90% less risk of getting infected with HIV when compared to participants who took Truvada®.[5]

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Real-world effectiveness

In addition to clinical trials, real-world evidence from actual users has supported the efficacy of Truvada® as PrEP. The Centers for Disease Control and Prevention (CDC) conducted a study of Truvada® use among men who have sex with men and reported that individuals who took Truvada® consistently had a 90% reduced risk of acquiring HIV compared to those who did not use PrEP.[6]

According to the Centers for Disease Control and Prevention (CDC), consistent daily use of Truvada® can significantly decrease the likelihood of acquiring HIV through sexual activity by over 99%. For individuals who engage in injection drug use, Truvada® has been shown to reduce the risk of HIV transmission by more than 74%.[7]

Adherence is key

Adherence support (i.e., education and counseling) plays a vital role in maximizing the effectiveness of Truvada® as PrEP. According to a study published in Clinical Infectious Diseases, regular use of Truvada® was associated with a high level of protection, with no new HIV infections reported among participants who took the medication as prescribed.[8]

Potential side effects

It is crucial for individuals considering Truvada® as PrEP to consult with a healthcare provider who can assess the risks and benefits based on their specific circumstances. While Truvada® is generally well-tolerated, it is essential to understand its potential side effects. Some individuals may experience mild gastrointestinal symptoms, such as nausea and diarrhea, which are usually temporary and subside over time.[9] Rare cases of renal toxicity and decreased bone mineral density have also been reported, but they are typically reversible upon discontinuation of the medication [10].


Truvada® has proven to be highly effective in preventing HIV transmission when taken consistently and correctly. Clinical trials, real-world evidence, and adherence studies all support its use as an effective pre-exposure prophylaxis. However, it is essential to acknowledge that Truvada® is not 100% foolproof, and practicing safer sex methods, such as using condoms, can provide additional protection against other sexually transmitted infections. As always, it is recommended to consult with a healthcare professional to discuss individual risk factors and determine the best approach to HIV prevention. You can easily schedule an appointment with a healthcare provider via Everlywell's STD telehealth option.

PrEP for HIV prevention: how it works and more

How does Truvada® work?

How long does it take for Descovy® to become effective?


  1. Pre-exposure prophylaxis: Prep medication. Accessed May 18, 2023. URL.
  2. Grant RM, Lama JR, Anderson PL, et al. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010;363(27):2587-2599. doi:10.1056/NEJMoa1011205.
  3. Baeten JM, Donnell D, Ndase P, et al. Antiretroviral prophylaxis for HIV prevention in heterosexual men and women. N Engl J Med. 2012;367(5):399-410. doi:10.1056/NEJMoa1108524.
  4. What is DESCOVY® for PrEP? Descovy®. Accessed May 18, 2023.
  5. FDA approves first injectable treatment for HIV pre-exposure prevention. U.S. Food and Drug Administration. Accessed May 18, 2023.
  6. Centers for Disease Control and Prevention (CDC). Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2017 Update: A Clinical Practice Guideline. CDC website. Updated March 27, 2018. Accessed May 18, 2023.
  7. US Public Health Service: Preexposure prophylaxis for the prevention of HIV infection in the United States. Centers for Disease Control and Prevention. 2021. Accessed May 18, 2023.
  8. Liu AY, Cohen SE, Vittinghoff E, et al. Preexposure prophylaxis for HIV infection integrated with municipal- and community-based sexual health services. JAMA Intern Med. 2016;176(1):75-84. doi:10.1001/jamainternmed.2015.4683.
  9. Truvada® Medication Information Sheet for Patients. Accessed May 18, 2023.
  10. U.S. Food and Drug Administration (FDA). Truvada® (emtricitabine and tenofovir disoproxil fumarate) Tablets, for Oral Use. Full Prescribing Information. Revised March 2018. Accessed May 18, 2023.
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