- PrEP = pre-exposure prophylaxis — HIV-prevention taken before exposure.
- Four medications: Truvada, Descovy, Apretude and lenacapavir (plus generics & 2-1-1).
- About 99% effective from sex when taken as prescribed; ~74% from injecting.
- Prescription-only, with HIV testing and follow-up — and often free or low-cost.
01What is PrEP?
PrEP stands for pre-exposure prophylaxis — "prophylaxis" means prevention. It's a daily pill or a long-acting injection taken before possible exposure so that, if HIV enters the body, the medicine stops it from taking hold. PrEP is for people who are HIV-negative; it's different from PEP, which is emergency medicine started after a possible exposure.
02PrEP medication names & brands
There are four FDA-approved PrEP medicines (plus a way of using Truvada on demand). Here are the brand names, generic names, and who makes them:
| Brand | Generic name | Form | Maker | Guide |
|---|---|---|---|---|
| Truvada (+ generics) | emtricitabine / tenofovir DF (TDF/FTC) | Daily pill | Gilead + generics | Truvada → |
| Descovy | emtricitabine / tenofovir alafenamide (TAF/FTC) | Daily pill | Gilead | Descovy → |
| Apretude | cabotegravir (CAB) | Injection / 2 months | ViiV Healthcare | Apretude → |
| Yeztugo 2025 | lenacapavir | Injection / 6 months | Gilead | Injections → |
| "2-1-1" | on-demand Truvada (TDF/FTC) | Pills around sex | — | Options → |
03How does PrEP work, and how well?
PrEP builds a protective level of medicine in the cells HIV would try to infect, so the virus can't establish an infection. The key is taking it consistently:
- Injections (Apretude, lenacapavir) give very high protection when given on schedule — helpful if daily pills are hard.
- Protection drops sharply if doses are missed — see missed-dose guidance.
04PrEP dosage — how you take it
| Option | How to take it |
|---|---|
| Truvada / Descovy | One tablet, every day, around the same time. |
| Apretude | Two starter injections one month apart, then every 2 months at a clinic. |
| Lenacapavir (Yeztugo) | An initiation schedule, then an injection every 6 months. |
| 2-1-1 (on-demand) | 2 pills 2–24 h before sex → 1 at 24 h → 1 at 48 h. — anal sex, MSM only |
05PrEP side effects (overview)
Most PrEP side effects are mild and short-lived — nausea, headache, tiredness in the first weeks that usually settle within a month. The things worth monitoring differ by medicine:
Read the full PrEP side effects guide — by drug, by body area, and how long they last. Have a specific symptom? Our interactive body-map tells you what's expected on PrEP versus what needs attention — and builds a PDF report for your provider.
06Managing side effects & everyday questions
Short, practical, medically-reviewed guides for the day-to-day realities of taking PrEP:
07Who qualifies for PrEP?
US guidelines say PrEP should be offered to anyone who is HIV-negative and asks for it, and actively recommended if any of the following apply:
- A sexual partner who has HIV (especially if not virally suppressed).
- Condomless anal or vaginal sex with partners whose HIV status you don't know.
- A bacterial STI (syphilis, gonorrhoea or chlamydia) in the past 6–12 months.
- Sharing injection-drug equipment.
- You've used PEP and remain at ongoing risk.
Ready to start — or switch?
See how to get a prescription (including telehealth), what PrEP costs, and how to lower it.
08PrEP medication — frequently asked questions
QWhat are the most common brands of PrEP in the US?
Truvada (and its generics), Descovy, Apretude and — since 2025 — Yeztugo (lenacapavir). Truvada/generics and Descovy are daily pills; Apretude and Yeztugo are injections.
QWhat is the daily pill for HIV prevention called?
The daily PrEP pills are Truvada (or generic emtricitabine/tenofovir DF) and Descovy. One tablet a day.
QHow effective is PrEP?
About 99% effective at preventing HIV from sex when taken as prescribed, and at least 74% from injection drug use. Missing doses lowers protection.
QWhich companies make PrEP?
Gilead Sciences makes Truvada, Descovy and Yeztugo; ViiV Healthcare makes Apretude. Generic Truvada is made by several manufacturers.
QIs PrEP a prescription drug?
Yes — it's prescription-only and includes a negative HIV test before starting plus routine follow-up (usually every 2–3 months). See how to get PrEP.
QCan women take PrEP?
Yes. Truvada, Apretude and lenacapavir are all approved for vaginal exposure. Descovy and 2-1-1 on-demand dosing are not approved for vaginal sex.
QCan I buy PrEP online?
PrEP is available through licensed telehealth services that prescribe it and arrange local pickup or delivery, with the required lab tests. Only use licensed providers. See how to get PrEP.
QDoes PrEP protect against other STIs?
No — PrEP only prevents HIV. Use condoms and regular STI testing; ask your provider about Doxy-PEP to lower bacterial-STI risk.
Explore the full guide
🔬 Sources & review
- U.S. CDC — PrEP for the Prevention of HIV Infection: Clinical Practice Guideline (2021); "PrEP effectiveness".
- HIV.gov & MedlinePlus — PrEP basics; USPSTF PrEP Recommendation (2023).
- U.S. FDA — labelling for Truvada, Descovy, Apretude and Yeztugo (lenacapavir, 2025).
✔ Last medically reviewed: 7 July 2026 · Prepmedication.com Medical Review Team · Next review due: January 2027 · How we review →
Medical disclaimer. This guide is general information, not a diagnosis or prescription. Approvals, dosing and cost vary by country and change over time; always confirm your plan with a qualified clinician. If you may have been exposed to HIV in the last 72 hours, see PEP now.