Should You Take PrEP to Prevent HIV? We've Got the Facts

The drug is more than 90% effective at preventing the spread of HIV through sex. So why aren’t more docs prescribing it?

by Lara DeSanto Health Writer

There are almost 40,000 new HIV infections every year in the United States, despite the fact that we now have a drug that can cut the risk of getting the infection from sex almost completely: pre-exposure prophylaxis (PrEP). And med school curriculums could be the reason why more high-risk people aren’t taking this medication.

PrEP is a daily pill that helps prevent the transmission of HIV, the sexually transmitted infection (STI) that, when untreated, can develop into AIDS. But more than half of internal medicine residents have only poor or fair knowledge of PrEP, according to a new study published in the Journal of General Internal Medicine.

"We know now that if we train people [about prescribing PrEP], they'll do it," said lead study author Christopher Terndrup, M.D.,assistant professor of medicine in the Oregon Health and Science University School of Medicine in Portland, Oregon. "We just need to make sure that's happening."

The study asked 229 residents at five academic medical centers about their knowledge of PrEP, and while 96% said they’d at least heard of the medication, most knew little about its effectiveness, side effects, and more.

"Residents who rated their knowledge more highly reported a greater likelihood of prescribing PrEP in the future," the authors said in the study.

What Is PrEP and How Does It Work?

PrEP is a drug (sold under the brand name Truvada) that can prevent HIV infection in people who are at high risk, such as those who have an HIV-positive partner, according to the Centers for Disease Control and Prevention (CDC). If you take PrEP correctly (every day), the drug is highly effective at blocking the HIV virus, according to studies.

And just how effective is “highly effective?” Well, according to the CDC, PrEP can reduce your risk of getting HIV from unprotected sex by more than 90% and from injection drug use by more than 70%. Condoms are still recommended to increase your protection and to help prevent other STIs.

The U.S. Preventive Services Task Force recently released a draft statement that officially joins the CDC in recommending that that doctors should offer PrEP, along with effective antiretroviral therapy, to people at high risk of HIV.

"Given the significant need for PrEP, [internal medicine] residents should be trained to achieve adequate knowledge and comfort levels to prescribe it," the study authors wrote.

Who Should Consider Taking PrEP?

According to the CDC, candidates for PrEP include:

  • People without HIV who are in an ongoing sexual relationship with an HIV-positive partner.

  • Someone who is not in a mutually monogamous relationship (which is a relationship in which you only have sex with each other) with a partner who recently tested negative for HIV and is a:

    • gay or bisexual man who has had anal sex without a condom or been diagnosed with an STD in the past 6 months, or

    • heterosexual man or woman who doesn’t regularly use condoms with partners of unknown HIV status who are at substantial risk (like people who inject drugs or women who have bisexual male partners).

  • People who have injected drugs in the past 6 months, have shared needles, or worked or been in drug treatment in the past 6 months.

You should also think about taking PrEP if you have a sex partner who has HIV and you’re considering getting pregnant. The drug can help protect you and your baby while you try to conceive, throughout pregnancy, and during breastfeeding.

Want to start taking PrEP? Talk to your doc—many insurance plans cover the drug. If you don’t have insurance or need help paying for PrEP, the company that sells the drug, Gilead, offers a cost assistance program that may be helpful. And know that you’re not locked into taking PrEP forever once you start—if you want to stop using it, you can, but you should at least continue taking it for one month following your last possible exposure to HIV.

Want to learn more about PrEP? Check out these helpful articles from HealthCentral’s sister site TheBody, an HIV/AIDS resource.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at