Pre-exposure prophylaXis, better known as PrEP, refers to antiretroviral pills or injections taken regularly to prevent HIV. Although PrEP is highly effective, it has yet to reach its full potential: Less than a third of people who could benefit from PrEP are using it.

There are currently three approved PrEP options:

  • Truvada (tenofovir disoproxil fumarate/emtricitabine, or TDF/FTC) was approved for PrEP in 2012. It is indicated for all populations at risk for HIV. It is usually taken once daily, but using it “on demand” before and after sex (PrEP 2-1-1) also works well. Studies of cisgender gay men and transgender women showed that daily Truvada is around 99% effective if used consistently. Truvada PrEP is also effective for cisgender women, but they may need to maintain better adherence. Truvada is generally well tolerated, but it can cause minor side effects, such as nausea, that usually resolve over time. TDF can cause kidney problems and bone loss in susceptible individuals.
  • Descovy (tenofovir alafenamide/emtricitabine, or TAF/FTC) was approved for PrEP in 2019. It is indicated for cisgender men and transgender women, but due to a lack of evidence, it is not yet approved for people exposed to HIV via vaginal sex. Descovy is taken once daily. The DISCOVER trial showed that daily Descovy PrEP is as effective as daily Truvada for cisgender gay men and trans women; studies of cisgender women are underway. Descovy is also generally well tolerated. TAF is easier on the kidneys and bones than TDF, but it has been linked to elevated blood fat levels and weight gain.
  • Apretude (long-acting cabotegravir) was approved for HIV prevention in 2021. It is indicated for all populations at risk for HIV. It is an injection administered by a health care provider every other month. The HPTN 083 trial showed that Apretude was even more effective than daily PrEP pills for cisgender gay men and transgender women, while HPTN 084 found that it was substantially more effective for cisgender women in Africa. Apretude is generally well tolerated. The most common side effect is temporary pain, redness or swelling at the injection site.

Accessing PrEP

PrEP is for HIV-negative people at increased risk for acquiring the virus, including those who have sex partners who are HIV positive or of unknown status, do not consistently use condoms or have recently been diagnosed with a sexually transmitted infection. PrEP is also indicated for people who inject drugs, but there has been little research on its effectiveness for this group.

An estimated 1.2 million Americans could benefit from PrEP, but only about 30% had a prescription in 2021, according to the CDC. While urban white gay men have eagerly adopted PrEP, uptake has been slower for other groups, including Black and Latino gay men, women, adolescents and young adults, and people in rural areas.

In an effort to improve uptake, the CDC now advises that providers should inform all sexually active adults and adolescents about PrEP and prescribe it to anyone who asks for it, as this may “help patients overcome embarrassment or stigma that could prevent them from telling their health care provider about their HIV risk factors.”

Truvada, Descovy and Apretude are expensive, but most people can get PrEP for free or at reduced cost. Generic TDF/FTC is now widely available. Private insurers will soon be required to cover all types of PrEP. Other coverage options include Medicaid, Medicare, city and state PrEP programs and financial assistance from Gilead Sciences or ViiV Healthcare. Many AIDS service organizations have navigators who can help you find a way to access PrEP.