What is the difference?
PEP means post-exposure prophylaxis: medicine you take after a risk to stop an infection before it settles. There are two very different kinds.
DoxyPEP is one dose of 200 mg doxycycline, an antibiotic. It lowers the risk of syphilis and chlamydia a lot, and gonorrhoea partly. HIV PEP is a course of HIV medicines that you take every day for 28 days, to prevent HIV. One cannot replace the other.
One dose versus 28 days
The biggest practical difference: doxyPEP is done in one moment, HIV PEP takes four weeks.
Side by side
| DoxyPEP | HIV PEP | |
|---|---|---|
| Protects against | Syphilis, chlamydia, partly gonorrhoea | HIV |
| Type of medicine | Antibiotic (doxycycline) | HIV medicines (antiretrovirals) |
| How you take it | 2 tablets of 100 mg, once | Daily for 28 days |
| When to start | Within 72 hours, ideally 24 | As soon as possible, within 72 hours |
| Where to get it | Online with a doctor's check, or a clinic | Sexual health clinic or emergency department |
| Keep at home? | Yes | No |
Which one do I need?
It depends on the risk you took. Worried about bacterial STIs after sex without a condom? DoxyPEP fits. Possible exposure to HIV, for example sex without a condom with a partner whose HIV status you do not know, and you do not use PrEP? Then you need HIV PEP, quickly.
Sometimes you need both. They work against different infections, so they can be taken together. If you use PrEP correctly, you are already protected against HIV and usually do not need HIV PEP.
Possible HIV exposure? Do not wait. HIV PEP works best when started within hours. Go to a sexual health clinic today, or to an emergency department outside opening hours.
And PrEP?
PrEP is taken before sex and protects against HIV only. Many people who use doxyPEP also use PrEP: together they cover HIV and the most common bacterial STIs. Read more in doxyPEP or PrEP.
