What is PrEP and how does it work?

Short Answer

PrEP is a medication that prevents HIV infection when taken consistently — a daily pill or bimonthly injection that reduces the risk of getting HIV from sex by about 99%.

How It Works

PrEP (Pre-Exposure Prophylaxis) puts anti-HIV medication in your body before exposure, so the virus can't establish an infection. It's like a contraceptive pill for HIV.

• Daily pill: Truvada or Descovy (generics available)
• Injectable: Apretude, taken every 2 months (increasingly popular)
• On-demand ("2-1-1"): Some regimens work for men who have sex with men — 2 pills before sex, 1 daily while exposed, 2 after.

Who Should Consider It

• Men who have sex with men
• Trans women (particularly with HIV-positive partners)
• Anyone with a partner living with HIV
• Anyone who finds condoms inconsistent
• People who inject drugs

If you've had condomless sex with someone whose status you don't know, PrEP is worth asking your provider about.

How to Get It

1. Ask any doctor or clinic — PrEP is a standard prescription.
2. Many LGBTQ+ clinics and Planned Parenthood offer it on informed consent.
3. US telehealth: Folx Health, Plume, Q Care Plus. UK: free via NHS sexual health clinics (Dean Street etc.).
4. Many countries and US states provide PrEP free or heavily subsidized.

What It Doesn't Do

• Doesn't prevent other STIs (get regular STI testing)
• Doesn't prevent pregnancy
• Requires consistent use — skipping doses lowers protection
• Requires HIV testing every 3 months while on it

Side Effects

Most people tolerate PrEP well. Mild side effects (nausea, headache) usually pass in the first weeks. Kidney monitoring via blood tests is standard.