Could a single antibiotic dose after sex stop STIs?

NCT ID NCT07397403

First seen Jun 26, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tests whether taking a single 200 mg dose of doxycycline within 24–72 hours after unprotected sex can prevent gonorrhea, chlamydia, and syphilis in men who have sex with men. Researchers in Bangkok will enroll 400 participants and follow them for 12 weeks. If effective, this could offer a new prevention tool for high-risk individuals.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

doxycycline

What this could lead to

If it works, this could provide a simple, on-demand pill to reduce the risk of common sexually transmitted infections in high-risk groups.

What could go wrong

This is a single-site trial in Thailand, so results may not apply elsewhere. Doxycycline may not prevent all STIs, and overuse could lead to antibiotic resistance.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

chlamydia infectious disease chlamydia trachomatis infectious disease prevention target gonorrhea prevention target syphilis prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Study contacts

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

Locations

  • Bangrak STIs Center

    RECRUITING

    Sathorn, Bangkok, 10120, Thailand

    Contact Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact