References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Pre-exposure prophylaxis (PrEP) is HIV medication taken by HIV-negative people to prevent infection. When taken as prescribed, PrEP reduces HIV risk by over 99%. It’s free on the NHS through sexual health clinics for people at higher risk. PrEP is one of the most effective HIV prevention tools available.
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How PrEP Works
| Feature | Detail |
|---|---|
| Drug | Truvada (emtricitabine/tenofovir) or generic |
| Effectiveness | Over 99% when taken correctly |
| Dosing | Daily or event-based (2-1-1 for MSM) |
| Cost | Free on NHS |
| Follow-up | Every 3 months (HIV test, STI screen, kidney check) |
Who Should Consider PrEP
- MSM at higher risk
- Trans people with sexual risk factors
- Partners of HIV-positive people not confirmed undetectable
- Anyone at substantial HIV risk
How to Access
- Visit an NHS sexual health clinic
- HIV test (must be negative)
- STI screening and kidney check
- Prescription provided free
- Follow-up every 3 months
PrEP Does NOT Protect Against
- Other STIs
- Pregnancy
Read more: PrEP benefits and risks | How to get PrEP | Truvada vs Descovy
Frequently Asked Questions
Is PrEP really free?
Yes — free on the NHS through sexual health clinics.
Do I need to take it every day?
Daily is most reliable. Event-based is an option for some MSM.
Does PrEP have side effects?
Mild nausea and headache in the first few weeks, usually settles.
Related reading
- Are HIV Tests Accurate If You're on PrEP, PEP or ART?
- Blood Test for Syphilis, Hepatitis B and Hepatitis C
- Can You Get an STI From Being Fingered?
- Can You Catch an STI From a Toilet Seat?
- Can You Clear HPV Once You Have It?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
