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.
Chlamydia is one of the most common STIs affecting gay and bisexual men and other men who have sex with men (MSM). It can infect the urethra, throat or rectum, depending on the type of sexual contact. Many cases have no symptoms, which is why regular comprehensive testing is important — including throat and rectal swabs, not just urine tests.
Here’s a practical guide.
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Where Chlamydia Can Affect MSM
| Site | Activity | Symptoms |
|---|---|---|
| Urethra | Receiving oral or being the insertive partner | Discharge, burning on urination — or none |
| Throat | Giving oral sex | Usually silent; mild sore throat possible |
| Rectum | Receptive anal sex | Often silent; rectal pain, bleeding or discharge possible |
Why Comprehensive Testing Matters
- Standard urine tests only catch urethral infection
- Throat and rectal infections are common and often silent
- Missing these sites means ongoing transmission and potential complications
- UK guidelines recommend throat and rectal swabs for MSM at risk
LGV: The Serious Form
Lymphogranuloma venereum (LGV) is a specific strain of chlamydia that causes more severe symptoms. It’s particularly prevalent in MSM networks in the UK. Features include:
- Rectal pain, bleeding and discharge
- Genital ulcers (sometimes)
- Swollen groin lymph nodes (buboes)
- Can mimic inflammatory bowel disease
- Needs longer antibiotic treatment than standard chlamydia
See our LGV guide for details.
Testing Recommendations for MSM
- Every 3-6 months if at higher risk
- Include HIV, syphilis, gonorrhoea and chlamydia
- Throat and rectal swabs if you have oral or anal sex
- Home testing kits available through NHS services
Treatment
- Uncomplicated chlamydia — doxycycline 100mg twice daily for 7 days
- LGV — doxycycline 100mg twice daily for 21 days
- Avoid sex (including oral) for 7 days after starting treatment
- Partners should be notified, tested and treated
Partner Notification
Sexual health clinics can help notify recent partners confidentially. This is important for breaking transmission chains. You can choose to do it yourself, or ask the clinic to contact partners without identifying you.
Prevention
- Condoms for anal sex (combined with PrEP for HIV protection)
- Regular STI testing
- DoxyPEP (where available) can reduce bacterial STI risk
- Partner communication about testing and status
Read more: What is chlamydia? | LGV guide | Chlamydia from oral sex
Frequently Asked Questions
How often should gay men test for chlamydia?
Every 3-6 months if at higher risk. Include throat and rectal swabs if you have oral or anal sex.
Is rectal chlamydia different from urethral chlamydia?
The same bacterium, but infection at different sites. Treatment is the same unless LGV is identified, which needs longer antibiotics.
Can I catch chlamydia if my partner is undetectable for HIV?
Yes. U=U protects against HIV only. Chlamydia and other STIs can still be transmitted.
Related reading
- Abnormal Genital Discharge and Chlamydia
- Can Mycoplasma Genitalium Be Cured?
- Can You Get Chlamydia From Kissing?
- Can You Have Chlamydia and Test Negative?
- Can You Get Chlamydia From Oral Sex?
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.
