Truvada and Descovy are both daily PrEP pills that prevent HIV. They differ in who they're approved for. Truvada covers anyone at risk through sex or injection drug use; Descovy is approved for sex-based risk only and is not approved for people at risk through receptive vaginal sex. Descovy carries a gentler kidney and bone profile.
risk reduction, taken as prescribed
daily Truvada/Descovy or the Apretude injection
not other STIs or pregnancy
| Item | Value |
|---|---|
| From sex | ~99% — risk reduction, taken as prescribed |
| From injection use | ≥74% |
| Forms | pill or shot — daily Truvada/Descovy or the Apretude injection |
| Protects against | HIV only — not other STIs or pregnancy |
What each one is
PrEP — pre-exposure prophylaxis — is medicine that HIV-negative people take before a possible exposure to keep HIV from taking hold. You take it on an ongoing basis rather than once CDC, Talk PrEP Together. Both Truvada and Descovy are once-daily oral pills, each combining two antiretroviral drugs that block HIV from copying itself if the virus enters your body.
Truvada is the older, broader option. It's approved for people at risk through sex or through injection drug use, which makes it the only one of the two pills cleared for someone who shares needles. Descovy is a newer formulation built on a different version of one of those two drugs, tweaked to ease the strain on the kidneys and bones. Its approval is narrower: Descovy is for people at risk through sex only, and it has not been studied or approved for people assigned female at birth who are at risk through receptive vaginal sex.
Neither pill protects against other STIs like chlamydia, gonorrhea, or syphilis, and neither prevents pregnancy. PrEP guards against HIV only, so people on it still need regular STI screening — you can get tested alongside your PrEP check-ins.
The key differences
Who they're approved for
This difference decides most cases. Truvada is approved for HIV prevention in people at risk through sex and in people who inject drugs. Descovy is approved for people at risk through sex only, and explicitly excludes those at risk through receptive vaginal sex. If you have a vagina and your exposure risk is vaginal, your option is Truvada or injectable PrEP; Descovy isn't on the table.
Kidney and bone profile
The reformulated drug in Descovy delivers the same active medicine to immune cells while putting less of it into the bloodstream, so the kidneys and bones see less of it. That can matter for someone with reduced kidney function or osteoporosis risk, or anyone whose labs already sit near the edge of normal. Truvada is well-tolerated by most people, but its older formulation is the reason your clinician monitors kidney function while you're on it.
How well they work
Both pills are highly effective when taken as prescribed. PrEP reduces the risk of getting HIV from sex by about 99% when taken consistently, and it lowers the risk from injection drug use by at least 74%. Protection depends on taking the pill on schedule, so occasional use won't do it.
How long until you're protected
Protection doesn't switch on the moment you swallow the first pill. For receptive anal sex, the medicine reaches maximum protection in about 7 days. For receptive vaginal sex and for injection drug use, it takes about 21 days. Because of that timeline PrEP can't be used as morning-after coverage — see when to test after exposure if you're worried about a recent risk.
Truvada vs Descovy: side-by-side
| Truvada | Descovy | |
|---|---|---|
| Form | Daily oral pill | Daily oral pill |
| Approved for sexual exposure | Yes — all routes | Yes, except receptive vaginal sex |
| Approved for injection drug use | Yes | No |
| For people at risk through receptive vaginal sex | Yes | Not approved |
| Kidney/bone profile | Standard; monitored on labs | Gentler on kidneys and bones |
| Reduction in HIV risk from sex (as prescribed) | About 99% | About 99% |
Which one applies to you
Start with your risk route, because that narrows the field fast:
- If you inject drugs (or your risk includes both sex and injection), Truvada is the pill for you, since Descovy isn't approved for injection risk.
- If you're a woman or anyone at risk through receptive vaginal sex, Truvada is your oral option; Descovy is not approved for that exposure.
- If your risk is sexual and your kidney or bone health is a concern — reduced kidney function, osteoporosis, or borderline labs — Descovy's gentler profile may be the better fit.
- If you'd rather not take a daily pill at all, ask about Apretude (cabotegravir), an injectable PrEP for people at risk through sex who weigh at least 77 pounds (35 kg).
Not sure whether you're a candidate for PrEP in the first place? Our who should take prep? eligibility guide walks through who benefits most. And if you're HIV-positive rather than HIV-negative, PrEP isn't your path — effective treatment is, since earlier hiv treatment can help prevention by suppressing the virus so it can't be passed on.
The practical next step
Getting started is more straightforward than people expect. You'll need an HIV test first to confirm you're negative, because starting PrEP while already infected can cause drug resistance. After that, you'll have regular check-ins — typically every few months — to retest for HIV, screen for other STIs, and check the labs that watch your kidneys. Both pills can be prescribed by a primary care clinic or through telehealth services, and assistance programs exist to cover the cost for people who'd otherwise struggle to afford it.
The most common mistake I see is treating PrEP like a morning-after pill. It only works taken on an ongoing schedule, and it takes days to weeks to reach full protection, so it can't bail you out after last night. PEP is the emergency option taken after a single possible exposure, and the two aren't interchangeable CDC, Preventing HIV with PEP. PrEP also covers HIV and nothing else, so keep up your routine STI testing while you're on it.
When to talk to a clinician
Bring up PrEP if you have an HIV-positive partner, multiple partners, inconsistent condom use, a recent STI, or you share injection equipment. A clinician will weigh your specific risk route against your kidney and bone health to pick between Truvada, Descovy, or the injectable, and they'll set up the testing schedule that keeps PrEP working safely. If you think you've had a possible exposure in just the last few days, don't wait for a PrEP appointment; that's a PEP conversation, and it's time-sensitive.