Truvada - A Pill That May Prevent HIV Infection

Truvada is a once-daily pill taken by people who don't have HIV to keep from getting it, a strategy called PrEP (pre-exposure prophylaxis). Taken consistently, it lowers the risk of getting HIV from sex by about 99% CDC. It prevents HIV, but it won't cure or treat an existing infection.

What Truvada is: prevention, not a cure

Truvada combines two antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (the label sometimes shortens this to FTC/TDF). When you take it daily, the medicine builds up in the cells lining your genital and rectal tissue, so if HIV gets into the body it can't establish a permanent infection. Think of it as a standing defense you keep stocked rather than something you reach for after the fact.

PrEP is one of the CDC's core prevention tools alongside condoms, treatment-as-prevention, and PEP. It does not cure HIV, and it isn't the emergency option. If you think you were exposed in the last few days, that calls for a different drug strategy started urgently. PrEP protects you going forward, taken before exposures happen.

How well does Truvada work?

Adherence is the whole story with PrEP. The landmark iPrEx trial showed a once-daily TDF-FTC tablet reduced HIV acquisition by about 42% overall among men who have sex with men and transgender women. Among participants who actually had detectable drug in their blood, protection was estimated above 90% iPrEx Trial (PMC). The pill works extraordinarily well; the misses came from missed doses.

Current guidance puts the real-world number for people who take it as prescribed at roughly 99% protection from sexual exposure, and at least about 74% for people who inject drugs. Truvada needs a few days of daily dosing to reach full protective levels in the body, so it isn't a same-day shield. Start it before you need it, and keep taking it.

Who Truvada PrEP is for

PrEP is for people who are HIV-negative and have an ongoing chance of exposure through sex or shared injection equipment. You might consider it if you have a partner living with HIV (especially if their virus isn't yet suppressed), if you have multiple partners or partners whose status you don't know, if condoms aren't used consistently, if you've had a recent STI, or if you share needles or other injection gear.

Truvada is approved across all the major exposure routes, anal sex, vaginal sex, and injection drug use, which is part of why it remains a workhorse option. For people weighing whether a daily pill fits their life, PrEP is one of several layers, and it's reasonable to ask preventing HIV without PrEP before deciding. If you're a transgender woman thinking through PrEP alongside gender-affirming care, the interaction with hormones is a common and answerable question, see our guide on transgender women & HIV.

Truvada vs Descovy vs the injectable (Apretude)

There's more than one way to do PrEP now, and the right choice depends on your anatomy, your exposure routes, and whether a daily pill or a periodic shot fits your life better. Two daily pills and a long-acting injection are FDA-approved options.

Descovy pairs emtricitabine with a newer form of tenofovir (tenofovir alafenamide), which is gentler on the kidneys and bone. Descovy was not studied in people exposed through receptive vaginal sex, so it isn't approved for that route or for people who inject drugs. Truvada is. Apretude is cabotegravir, given as a shot rather than a pill: two starter doses a month apart, then an injection every two months. In the HPTN 084 trial in cisgender women, the cabotegravir shot lowered HIV risk by 88% compared with daily TDF-FTC, with no doses to forget HPTN 084.

Newer long-acting options are arriving. In 2025 the CDC added injectable lenacapavir, given under the skin twice a year, as a PrEP option, updating the 2021 guideline on the strength of two randomized trials CDC, 2025. Truvada isn't obsolete. PrEP is now a menu, and a daily pill remains a proven, affordable, widely available choice.

Side effects and the monitoring it needs

Most people tolerate Truvada well. In the first weeks some notice mild nausea, headache, or stomach upset, a so-called start-up syndrome that usually settles on its own. The effects worth monitoring are subtler and show up over time: tenofovir disoproxil fumarate can put a small strain on kidney function and can slightly lower bone mineral density. PrEP isn't a fire-and-forget prescription.

Before you start, your clinician confirms you're HIV-negative and checks kidney function, hepatitis B status, and STIs. Starting PrEP with an undiagnosed HIV infection can breed drug resistance, the single most important reason for that first test. On oral PrEP you return roughly every three months to repeat the HIV test, refill, and recheck labs as needed; the injectable runs on a two-month visit cadence. Those visits are also a built-in chance to screen for other STIs that PrEP doesn't touch.

Cost and how to get it

PrEP is covered without cost-sharing by most insurance plans because it carries a top USPSTF recommendation, and the clinic visits and lab work tied to it are generally covered too. If you're uninsured or underinsured, the medication manufacturers run patient-assistance programs, and federal and state programs help with both the drug and the required monitoring, many people pay little or nothing once enrolled. Generic versions of Truvada have also brought the pill cost down sharply.

Ask your primary care provider, a sexual-health clinic, or a Planned Parenthood about starting PrEP and which assistance program fits you. Worldwide more than 2.5 million people were on PrEP in 2022, yet it's still reached far fewer people than could benefit. Cost is rarely the real barrier once someone walks through the door PubMed PrEP for HIV.

What Truvada does NOT protect against

Truvada blocks HIV and nothing else. It offers no protection against other sexually transmitted infections, gonorrhea, chlamydia, syphilis, herpes, or HPV, so condoms and regular screening still matter while you're on PrEP. People on PrEP often have STIs picked up precisely because they're getting tested every few months.

It also doesn't prevent pregnancy, and it won't help if you already have HIV. It's a prevention drug, not a treatment. Keep your routine STI checks on the calendar; you can get tested alongside your PrEP visits, and if you want to weigh your options you can compare testing providers.

When to see a clinician

See a provider to start PrEP before you anticipate ongoing exposure, not after a single scary night. If you think you were exposed in the past few days, that's a different and urgent conversation: post-exposure prophylaxis (PEP) must begin within 72 hours and is an urgent-care or ER situation, not a wait-and-see one CDC. PrEP picks up from there to protect you going forward.

Book a visit promptly if you develop flu-like symptoms, fever, rash, sore throat, swollen glands, within a few weeks of a possible exposure, since that's exactly when an acute HIV infection is most contagious and worth ruling out fast. Timing your test to the exposure matters; here's when to test after exposure.

Keep exploring on EasySTD: what STD testing costs, your risk of an STD and HIV/AIDS testing.