You may have been exposed — here's what helps

Maybe a partner told you they tested positive, a condom broke, or you had sex you're now worried about. There are real, effective options — and some of them are time-sensitive, so it's worth acting soon.

PEP — emergency medicine to prevent HIV (within 72 hours)

PEP (post-exposure prophylaxis) is medicine that can prevent HIV after a possible exposure. It works best the sooner you start:

• Start within 72 hours (3 days) of the exposure — the earlier the better.
• You take it every day for 28 days.
• If it may have been in the last 3 days, treat this as urgent — come in or go to urgent care / emergency to ask about PEP right away.

PrEP — medicine to prevent HIV before exposure

If exposures are likely to happen again, PrEP (pre-exposure prophylaxis) is a medicine you take before exposure to stop HIV from taking hold. It can be taken daily, or "on-demand" around specific events. Ask the clinic whether PrEP is a good fit for you.

Doxy-PEP — reducing bacterial STIs after sex

Doxy-PEP is a single dose of the antibiotic doxycycline (200 mg) taken within 72 hours after condomless sex to lower the chance of getting chlamydia and syphilis (and, less reliably, gonorrhea).

It is a conditional recommendation (based on moderate-certainty evidence) from Canada's national STBBI committee, made in June 2025 and published in November 2025, for gay, bisexual and other men who have sex with men (GBMSM) and transgender women. It is not currently recommended for cisgender women, where the evidence hasn't shown the same benefit. Talk to a clinician about whether it fits your situation.

U = U — if a partner is living with HIV

Undetectable = Untransmittable. When someone with HIV is on treatment and the virus is undetectable, they cannot pass HIV to sexual partners. If your partner is on effective treatment and undetectable, your risk of HIV from them is effectively zero.

Then: get tested at the right time

After starting any of the above, plan to get tested — but remember the window period means very early tests can miss an infection (see "I want to get tested" for timing). You may test now and again later.

If you might have been exposed to HIV, PEP must start within 72 hours — the fastest route is our after-hours clinic; otherwise book an appointment as soon as possible. How to arrange this at AHC: you can book an appointment with your Ajax Harwood Clinic provider, or come to our after-hours clinic. AHC is a family practice with after-hours care — we are not a walk-in clinic for people who are not AHC patients, and we do not take outside referrals for STI care.