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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. HIV.gov. https://www.hiv.gov/hiv-basics/hiv-prevention/using-hiv-medication-to-reduce-risk/pre-exposure-prophylaxi. 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. https://www.nejm.org/doi/full/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. https://pubmed.ncbi.nlm.nih.gov/22784037/.
  4. What is DESCOVY® for PrEP? Descovy®. https://www.descovy.com/clinical-trial-efficacy-results. Accessed May 18, 2023.
  5. FDA approves first injectable treatment for HIV pre-exposure prevention. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-approves-first-injectable-treatment-hiv-pre-exposure-prevention. 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. https://www.cdc.gov/hiv/pdf/risk/prep/cdc-hiv-prep-guidelines-2017.pdf. 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. https://www.cdc.gov/hiv/pdf/risk/prep/cdc-hiv-prep-guidelines-2021.pdf. 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. https://pubmed.ncbi.nlm.nih.gov/26571482/.
  9. Truvada® Medication Information Sheet for Patients. https://www.cdc.gov/hiv/pdf/prep_gl_patient_factsheet_truvada_english.pdf. 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. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021752s062lbl.pdf. Revised March 2018. Accessed May 18, 2023.
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