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PrEP vs PEP?

Dr. Demetre: We got a great question. PrEP and PEP, are they the same thing?
Dr. David: Got questions about PrEP? #AskTheHIVDoc has all the answers.
Dr. Demetre: PrEP and PEP are different. PrEP is pre-exposure prophylaxis. PEP is post-exposure prophylaxis. PrEP is a medicine that you take everyday to prevent HIV. If you’re at risk for HIV, that means if sometimes you don’t use condoms, you can take PrEP, and there’s over 90% reduction in HIV risk. That’s better than the odds of a flu shot in preventing the flu. Post-exposure prophylaxis, that’s a medicine that you take in an emergency. So, let’s say something happens, you have a condom break or you didn’t use condoms with one of your partners. You go to a doctor, a nurse or other healthcare provider, an emergency room, urgent care, whatever works for where you are and you say, this happened. I had condom-less sex. My condom broke. And they start you on medicines that you take for 28 days and it prevents infection. You have to do it pretty quickly. CDC says that you have to do it within 72 hours, get it as fast as you can get it, and it prevents HIV acquisition. So, remember, PEP is something you rely on in an emergency. So if you’ve done PEP, you should totally think about talking to your doctor about PrEP. It may be right for you. Because PrEP takes the emergency out of the equation, it just says, I don’t want to get HIV so I’m going to do something every day to prevent it.

PrEP and PEP – what’s the difference? In this video, Dr. Demetre explains the distinction between PrEP and PEP and how their uses are quite different. 

PrEP, which stands for PRE-exposure prophylaxis, is the daily pill that must be taken BEFORE a possible exposure to HIV. Remember it must also be taken for a certain number of days before it reaches maximum effectiveness. (Click here to learn more about timing and effectiveness).

PEP, short for POST-exposure prophylaxis, is an emergency option to reduce the risk of contracting HIV AFTER a possible exposure. PEP involves starting a triple-drug combination of HIV drugs within 48 to 72 hours of the possible exposure and staying on the daily regimen for a month.

Any healthcare provider can prescribe PrEP and PEP, but not all may be familiar with them. If yours is not, click here to find a PrEP-friendly provider near you.


#AskTheHIVDoc is a video series from Greater Than HIV featuring top HIV doctors providing answers to commonly-asked questions about HIV prevention, testing and treatment.

This information is shared for educational purposes only and should not be used as a substitute for professional medical advice. The views expressed are those of the featured medical professional and reflect information available to that professional at time of filming. Always consult a health care provider for any personal health decision.

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