What is PrEP?

PrEP (pre-exposure prophylaxis) is an HIV medicine that you take before sex. Taken correctly, it prevents HIV almost completely.

Most people take one pill every day. Some people use an on-demand schedule around sex, and in some countries PrEP is also available as an injection. PrEP is prescribed with regular check-ups for HIV, STIs and your kidneys.

What is doxyPEP?

DoxyPEP is one dose of 200 mg of the antibiotic doxycycline, taken after sex without a condom. It lowers the chance of syphilis and chlamydia strongly, and of gonorrhoea partly. Read more in what is doxyPEP.

Can you use doxyPEP and PrEP together?

Two different neutral tablets side by side, white and light blue

Yes. There is no known interaction between doxycycline and the usual PrEP medicines. In fact, most people in the doxyPEP studies were PrEP users: they were already protected against HIV and wanted protection against bacterial STIs as well.

Using both means your PrEP check-ups every three months already cover the STI tests that are also advised with doxyPEP. Tell the doctor who prescribes your PrEP that you use doxyPEP.

PrEP

Before sex, against HIV.

DoxyPEP

After sex, against syphilis and chlamydia.

Testing

Every 3 months, for both.

Condoms

Still the widest protection.

What is doxy PrEP?

You may also come across "doxy PrEP": taking doxycycline every day, before sex, like PrEP. That approach has only been studied on a small scale and uses far more antibiotic, which raises the risk of resistance. It is not recommended at the moment. DoxyPEP, one dose after sex, is the approach with the strongest evidence.

And HIV PEP?

HIV PEP is something else again. It is a 28-day course of HIV medicines after a possible HIV exposure, for people who do not use PrEP. It has to start within 72 hours, ideally within hours, at a clinic or emergency department. DoxyPEP does not replace it.

Frequently asked questions

What is the difference between doxyPEP and PrEP?
PrEP is an HIV medicine that you take before sex to prevent HIV. DoxyPEP is an antibiotic that you take after sex to prevent bacterial STIs such as syphilis and chlamydia. They protect against different infections.
Can I take doxyPEP and PrEP together?
Yes. There is no known interaction between doxycycline and the usual PrEP medicines. Most people in the doxyPEP studies were using PrEP.
Does PrEP protect against syphilis or chlamydia?
No. PrEP only protects against HIV. That is why some PrEP users add doxyPEP.
What is doxy PrEP?
Doxy PrEP means taking doxycycline daily before sex. It has only been studied on a small scale and is not recommended at the moment. DoxyPEP, one dose after sex, is the approach with the strongest evidence.