Who It a Good Fit for, and How to Take It

This information is developing, so we encourage you to check it again periodically for updates.

Is DoxyPEP Right for Me?

 Almost all of the research done on the effectiveness of DoxyPEP has focused on cis gay, bi, and other men who have sex with men, and transwomen, who are also, in general, disproportionately impacted by the bacterial STIs that DoxyPEP is effective at preventing. Those same bacterial STIs are easily transmitted by many kinds of sex without a condom, including anal, oral, and vaginal or fronthole sex, whether giving or receiving. We recommend speaking with your trusted healthcare professional or a nurse at a HIM Sexual Health Centre about whether DoxyPEP is a safer-sex tool that is best for you, especially if you’ve had a case of chlamydia, syphilis, or gonorrhea in the previous year.  

How Do I Take DoxyPEP?

 The trusted medical professional who prescribes you DoxyPEP is the best person to speak to about how to take DoxyPEP and whose guidance you should follow. Clinical guidelines have still not been published in Canada, but in the supporting research and according to guidelines that have been released elsewhere, DoxyPEP is taken as two 100mg pills of doxycycline (200mg total) no later than 72 (and ideally within 24) hours after oral, anal, or vaginal/front hole sex without a condom. It can be taken as often as once a day, taking no more than 200mg within 24 hours.  

 DoxyPEP should be taken with a full glass of water and you should remain upright (don’t lay down) for 30 minutes afterward. Taking it with food may help to reduce indigestion, a more common possible side effect. It’s important not to take antacids or supplements that contain calcium, iron, or magnesium within two hours before or after taking DoxyPEP. People who are pregnant should not take doxycycline.  

What are Potential Side Effects of DoxyPEP?

 Doxycycline is a common antibiotic that has been widely used for decades, rarely resulting in any serious side effects. The most common are an upset stomach or indigestion and nausea, sensitivity to the sun, and irritation or inflammation of the throat. Taking DoxyPEP with a full glass of water and possibly something to eat, staying upright for 30 minutes afterward, and wearing sunscreen if you’ll be going outside all help to reduce these most common side effects if you find yourself facing them.  

There are no known, clinically relevant interactions between doxycycline and gender-affirming hormone therapy.  

Will DoxyPEP work for me, as a trans person?

Most of the studies on doxy did include trans women in their target populations. In this community, DoxyPEP did seem to be effective similar to the gbMSM population; however, the number of trans women enrolled in the studies were often small which limits the generalizability of the results to all trans women and trans feminine folks.

Unfortunately, the studies did not include (at least not explicitly) trans men who have sex with men, therefore, it is unclear from the evidence if DoxyPEP would be effective for trans men and transmasculine folks. It is theoretically possibly to conceive that trans masculine folks/men who have sex with men could have relatively similar effects, but this is an extrapolation to an unstudied population, therefore, it is less certain.

Will DoxyPEP work for me, as someone living with HIV?

Research shows that DoxyPEP remains highly effective regardless of someone’s HIV status. However, that same research also suggested a slightly lower efficacy for people living with HIV, compared to HIV-negative folks. People living with HIV should consult their doctor or other trusted healthcare professional to make sure it’s a good and safe option for them.