Doxy-PEP
Reduce Risk of STIs like Chlamydia and Syphilis.
Learn all the facts about Doxy-PEP (the pros, the cons) to make the right decision for you.
What is Doxy-PEP?
Doxy-PEP is taking an antibiotic known as doxycycline within 72 hours after sexual activity (post-exposure prophylaxis).
This can reduce the risk of acquiring chlamydia, syphilis and possibly gonorrhea. Some studies have suggested it can reduce the risk of some STIs by approximately 60-90%.
But… there are some concerns on it’s use. These include antibiotic resistance, possible impact on our gut health, and whether it should have widespread use.
Studies on the use of Doxy-PEP have found it most beneficial in people who have a history of frequent and/or recent STIs.
However, Doxy-PEP is less effective against gonorrhea (see below), and it is still possible to get chlamydia and syphilis on it. So, we need to think about the risks versus benefits.
A significant concern is possible increased risk for antibiotic resistance.
This is where taking doxycycline more regularly could potentially lead to drug resistance. This would make it ineffective if ever needed for the treatment of STIs.
Responsible care providers know all of this and do not advocate automatic mass use of Doxy-PEP.
How is it typically taken?
A typical prescription for Doxy-PEP is taking two tablets (200mg) together within 72 hours after a possible risk exposure (and not to exceed 2 tablets in a 24 hour period).
For example, if a person had sexual activity on a Monday at 12pm they would need to take their dose before Thursday at 12pm.
Some providers are recommending to limit use to more higher risk encounters and to be mindful of the 72 hour window to maximize it’s use.
Some people may take their Doxy-PEP right after a sexual encounter. But if they anticipate there will be activity again within 72 hours it may be ideal to delay the Doxy-PEP dose to later in the window.
What are the Side Effects?
The medication is generally well tolerated, but like most antibiotics may cause stomach upset or possibly diarrhea.
There are concerns that with more frequent antibiotic use this can potentially impact the regular bacterial balance in our gastrointestinal tract. More long term data is needed on this.
The medication is taken with a lot of water, and you should not lie down for at least 30 minutes after taking it. This reduces the risk of throat irritation (or rarely ulceration).
Doxycycline may also make you more sensitive to sunlight (caution re: travel, tanning). It should also be spaced apart from multivitamins, minerals, and antacids. There are serious risks with some oral acne medication and should not be combined.
So about gonorrhea…
Some earlier studies suggested Doxy-PEP may provide some protection from acquiring gonorrhea.
However, some other investigations have found it may provide zero additional protection. A more recent 2025 report found an overall 12% reduction.
This is not surprising as many patients on Doxy-PEP with our clinic still are acquiring gonorrhea.
So, a person could be on Doxy-PEP to try to prevent an infection, and then still need additional antibiotics for treatment afterwards anyway.
How to get Doxy-PEP?
To get Doxy-PEP in Canada you’ll need a prescription.
If you are a current patient with us, Doxy-PEP services are offered through the clinic.
We offer online phone appointments across all of Ontario. If near our in-person clinics we also offer full-service care in Toronto, Brampton, and Ottawa.
For general questions about the medication our clinical pharmacists are also here to answer all your inquiries.
Patients must be either in ongoing PrEP care or HIV treatment care with our clinic to be prescribed Doxy-PEP.
Get Doxy-PEP with us
100% FREE
*for patients in ongoing PrEP or HIV care with the clinic
FAQs
Is Doxy-PEP available in Canada?
Doxycycline is commonly used in Canada for treatment of STIs and other infections. Doxy-PEP is considered an “off-label” use of doxycycline since it is not officially approved for use in this way in Canada.
Off-label is when a medication is prescribed by their care provider for a use that it was not officially approved for. This is not uncommon is prescribing practice and done with several other medications too.
Does Doxy-PEP prevent herpes?
No, Doxy-PEP is only known to be effective against chlamydia, syphilis, and with some protection against gonorrhea. It is not effective against herpes, HPV, hepatitis, or Mpox.
Is The PrEP Clinic offering Doxy-PEP to their patients?
Yes, we offer Doxy-PEP services. If you think it might be right for you we can book a consultation with a Nurse Practitioner to discuss and assess.
Is Doxy-PEP worth it?
As with any medication, you have to weigh the risks and benefits. Connect with our clinic team to determine if the medication would be appropriate for your needs.
Is Doxy-PEP used for HIV?
Doxy-PEP is not for HIV prevention. The term “PEP” is usually associated with post-exposure prophylaxis for HIV (HIV-PEP) but this is a different type of medication. Doxy-PEP and HIV-PEP are different.
Authors
- Nurse Practitioner Osahon
- Pharmacist Drew