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Guides / PrEP and PEP

What is doxyPEP and who should take it?

By Bud

Not medical advice. This guide is written from CDC and public health guidance and hasn’t been reviewed by a clinician yet. Sources checked . For advice about your own health, talk to a doctor or clinic. How we write guides · Health disclaimer

Pills in the palm of a hand, next to a pill box and a glass of water.
Photo by Towfiqu barbhuiya on Unsplash.

The short answer: doxyPEP means taking 200 mg of the antibiotic doxycycline within 72 hours after sex without a condom. The CDC recommends it for gay and bi men and trans women who’ve had syphilis, chlamydia or gonorrhea in the last year. It cuts syphilis and chlamydia by more than 70% and gonorrhea by about half.

Think of it as the morning-after pill for the bacterial STIs. You fuck, you take two pills the next day, and the bacteria that would have set up shop in your ass or throat get wiped out before they can.

How to take doxyPEP

The rules are short, and they matter.

  1. Take 200 mg of doxycycline (usually two 100 mg pills) as soon as you can after oral, anal or vaginal sex without a condom. Within 24 hours is best. Don’t go past 72 hours.
  2. Never take more than 200 mg in 24 hours. Had sex again the next day? Take your next dose 24 hours after the last one, not sooner.
  3. One dose covers everything in the last 24 hours. A Saturday with three guys is still one dose.
  4. Swallow it with a full glass of water and some food, and don’t lie down for 30 minutes. Doxycycline can burn your throat if it sits there.

It can also make you sunburn faster, so wear sunscreen in the days after a dose.

Who should take doxyPEP

The CDC’s doxyPEP recommendation
YouDoxyPEP?
Are a gay or bi man or a trans woman and had syphilis, chlamydia or gonorrhea in the last 12 monthsRecommended
Are a gay or bi man or a trans woman with no recent STI, but have lots of partners or go rawWorth asking about
Rarely have sex without condomsProbably not needed
Based on the CDC’s 2024 clinical guidelines on doxycycline postexposure prophylaxis. Clinicians can also offer it to others on a case-by-case basis.

Who the research was done on

The doxyPEP trials enrolled gay, bi and other men who have sex with men, and trans women. That’s why the CDC recommendation names those groups.

For everyone else, including cis women, straight cis men, trans men and nonbinary people assigned female at birth, the CDC says the evidence is limited, and your provider should decide with you. The only trial in cis women, run in Kenya, found no significant drop in STIs. Hair tests found doxycycline in only 29% of the women who were supposed to be taking it, so many probably weren’t taking it. Researchers haven’t ruled out biological differences either.

What doxyPEP doesn’t cover

DoxyPEP only works on bacteria. It does nothing against HIV, mpox, herpes, HPV or hepatitis. For HIV, you want PrEP or, after a scare, PEP.

It also doesn’t replace testing. The CDC says to test for STIs and HIV every 3 to 6 months while you’re on doxyPEP, because it lowers your risk without taking it to zero.

The catch: antibiotic resistance

Taking antibiotics often gives bacteria more chances to learn how to survive them. Gonorrhea is already good at this, which is partly why doxyPEP works less well against it. Researchers and the CDC are watching resistance closely. For now the advice is simple: take it only after sex, stick to the dose and keep testing.

How to get doxyPEP

Doxycycline is a cheap generic antibiotic, and any prescriber can write it. Ask for it at your PrEP visit, a sexual health clinic or your doctor. The CDC runs a doxyPEP finder with clinics that offer it. Ask for enough pills to keep a few doses at home, so you’re not hunting for a pharmacy the morning after.

Frequently asked questions

How soon after sex do I take doxyPEP?
As soon as you can, ideally within 24 hours and no later than 72 hours.

Can I take doxyPEP before sex?
No. It’s studied and recommended as a dose after sex. Taking it daily as PrEP isn’t recommended.

Is doxyPEP the same as PEP?
No. PEP is a 28-day course of HIV medicines after a possible HIV exposure. DoxyPEP is a single antibiotic dose for bacterial STIs.

Does insurance cover doxyPEP?
Doxycycline is a low-cost generic, and most insurance covers it. Without insurance, a pharmacy discount card usually keeps it cheap.

Sources: CDC doxyPEP guidelines (2024), CDC: Preventing STIs with doxyPEP.

This guide is general information, not medical advice. Talk to a doctor or clinic about your own situation. Health disclaimer

Not sure when to test? The STI test window calculator works out when each test can pick up an infection after sex.