The standard doxyPEP dose
The doxyPEP dose is 200 mg of doxycycline, taken once after sex without a condom. In a doxyPEP pack that means two tablets of 100 mg, swallowed together.
Take both tablets at the same time. Splitting them (one in the morning, one in the evening) gives a lower level of antibiotic at the moment it matters most, and that makes doxyPEP less effective.
This is the dose used in the large studies and in the guidelines of the US CDC, published in 2024: 200 mg within 72 hours after sex, and no more than 200 mg in 24 hours.
When to take it: 24 hours ideal, 72 hours latest
The sooner, the better. In the first hours after sex there are only a few bacteria, so the antibiotic has the best chance to stop them. After 72 hours doxyPEP is no longer recommended.
How often can you take doxyPEP?
As often as you need it, with one firm rule: never more than 200 mg in 24 hours. One dose covers all the sex you had in the 24 hours before it.
| Your situation | What to do |
|---|---|
| Sex on Friday night | One dose on Saturday morning |
| Two partners on the same night | Still one dose |
| Sex on Friday and on Saturday | Dose on Saturday morning, next dose on Sunday, at least 24 hours later |
| A whole festival weekend | One dose per day at most. Take the last dose within 72 hours after the last sex |
| Sex 4 days ago | Too late for doxyPEP. Get tested and talk to a doctor |
Doxycycline hyclate or monohydrate?
Both forms of doxycycline work for doxyPEP, at the same dose of 200 mg. The difference is in the salt the medicine is bound to. Some people find monohydrate a little easier on the stomach.
Missed the 72 hours?
Do not take a dose after 72 hours. Get tested for STIs about two weeks after the sex, or sooner if you notice symptoms. Worried about HIV? HIV PEP must be started within 72 hours at a clinic or emergency department.
How many doses are in one pack?
A doxyPEP pack contains 8 tablets of 100 mg: enough for 4 separate doses. Keep it at home so you can take your dose within the first 24 hours. See the doxyPEP price for what is included.
