PEP for HIV: What It Is, How It Works, and When You Need It

When you’ve had a possible exposure to PEP for HIV, post-exposure prophylaxis is a short-term antiretroviral treatment used to prevent HIV infection after a high-risk event. Also known as post-exposure prophylaxis, it’s not a vaccine — it’s an emergency response you start within 72 hours of exposure. Think of it like a fire extinguisher for your immune system: it doesn’t stop the virus from ever existing, but it can stop it from taking hold if you act fast.

HIV exposure, any situation where bodily fluids from an HIV-positive person enter your body through broken skin, mucous membranes, or needles can include unprotected sex, needlestick injuries, or sexual assault. PEP isn’t for everyday use — it’s for when something went wrong and you need to act quickly. The sooner you start, the better the chance it works. After 72 hours, it’s no longer effective. That’s why timing matters more than anything else.

Antiretroviral therapy, the class of drugs used in PEP, works by blocking HIV from copying itself in your cells. You’ll take a combo of 2–3 pills daily for 28 days. It’s not fun — nausea, headaches, and fatigue are common. But it’s not meant to be comfortable. It’s meant to be effective. People who start PEP on time and stick to the full course have a very low risk of turning HIV positive. Studies show it reduces infection risk by over 80% when taken correctly.

You don’t need to be a healthcare worker to need PEP. It’s for anyone who had a risky encounter — whether you’re unsure about your partner’s status, used a shared needle, or were assaulted. It’s not a judgment call. It’s a medical option. Clinics and ERs in Canada can provide it, even if you don’t have a doctor. You don’t need to prove exposure — you just need to explain what happened.

What PEP doesn’t do is protect you from future exposures. It’s not a substitute for condoms, PrEP, or clean needles. It’s a backup plan. If you’re at ongoing risk, talk to your provider about PrEP — that’s the daily pill for people who need long-term protection. PEP is for emergencies. PrEP is for prevention. They’re not the same thing.

And yes, side effects happen. But most people get through them. The real risk isn’t the pills — it’s waiting. If you think you were exposed, don’t wait until morning. Don’t wait until you’re sure. Call a clinic now. Every hour counts.

Below, you’ll find real-world guides on HIV treatments, drug interactions, and how to manage side effects — all from people who’ve been there. Whether you’re considering PEP, are on it right now, or just want to understand your options, these posts give you the facts without the fluff.