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.
Anal sex carries a higher risk of STI transmission than vaginal sex for most infections. The rectal lining is thinner and more fragile than the vaginal lining, making it more susceptible to micro-tears that allow bacteria and viruses to enter the body. Receptive anal sex (bottoming) carries more risk than insertive (topping), but both partners can acquire infections.
Get tested for rectal and genital STIs with a home kit
STI Risks from Anal Sex
| STI | Risk (Receptive) | Risk (Insertive) | Testing |
|---|---|---|---|
| HIV | High (1.4% per act) | Moderate (0.1%) | Blood test from 4 weeks |
| Gonorrhoea | High | Moderate | Rectal swab |
| Chlamydia | High | Moderate | Rectal swab |
| Herpes | Moderate-high | Moderate | Swab during outbreak |
| Syphilis | Moderate | Moderate | Blood test from 4 weeks |
| HPV | Moderate | Low | No routine test |
| Hepatitis A/B/C | Varies | Low | Blood test |
Why Anal Sex Carries Higher Risk
- The rectal lining is a single cell layer thick (vaginal lining is multiple layers)
- Micro-tears are common during anal penetration, creating direct entry points for pathogens
- The rectum has a rich blood supply close to the surface
- Natural lubrication is absent, increasing friction
How to Reduce Risk
- Condoms: Highly effective against HIV, chlamydia, gonorrhoea. Use water-based or silicone-based lubricant to reduce breakage
- Lubricant: Reduces micro-tears. Use plenty. Never use oil-based lubricant with latex condoms
- PrEP: Daily medication that prevents HIV. Available free on the NHS
- Regular testing: Include rectal swabs for chlamydia and gonorrhoea. Standard urine tests don’t detect rectal infections
- Hepatitis A + B vaccination: Recommended for anyone having anal sex
Important: Request Rectal Testing
Standard STI tests (urine sample) only detect genital infections. If you have receptive anal sex, you need a rectal swab to check for chlamydia and gonorrhoea in the rectum. Many infections are rectal-only with no genital symptoms. Always tell your clinic about anal sex so they test the right sites.
Read more: Anal herpes | What is HIV? | What is PrEP?
Frequently Asked Questions
Can you get an STI from anal sex with a condom?
Condoms significantly reduce risk but don’t eliminate it for herpes, HPV, and syphilis, which can spread through skin contact around the anus. Regular testing is still recommended.
Is anal sex safe if both partners are tested?
If both partners have recent negative STI tests and are mutually monogamous, the risk is very low. Testing should include rectal swabs, not just urine tests.
Related reading
- A to Z of Sex: Sexual Health Terms Explained
- Alcohol and HIV: What You Need to Know
- Anxiety and HIV: Coping and Getting Support
- Are All STIs Curable?
- Blood Problems and HIV: Anaemia, Low Platelets and More
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.
