PrEP vs PEP: What’s the Difference?

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Learn how the two prevention methods can work for you. 

While you may not think HIV is something that could ever affect you, it can if you’re sexually active. While HIV can’t be spread through saliva, it can spread through bodily fluids such as blood, semen, rectal or vaginal fluid.

This means HIV can be passed between partners if you have unprotected sex, or sex without a condom. Unprotected sex includes oral sex if a condom, internal condom or dental dam isn’t used between you and your partner. 

HIV can also be spread through shared needles. If you’re sexually active or share needles with others, Pre-Exposure Prophylaxis (PrEP) and Post-Exposure Prophylaxis (PEP) are pills that can be taken to prevent HIV infection.  

If you or someone you know is in need of HIV testing or is living with HIV, take control of your health at 

Who can use PrEP and PEP?


PrEP is a long-term pill for people who don’t currently have HIV but have a higher chance of contracting HIV.  

 PrEP can be taken if you: 
– Don’t use condoms 
– Have a sexual partner who has
– Have a sexual partner that has a
higher chance of getting HIV 
– Have unprotected anal or
vaginal sex with many partners 
– Recently had another STI
(chlamydia, gonorrhea, or
– Do sex work that includes
vaginal or anal sex 
– Share needles  


PEP is a short-term pill for people who don’t currently have HIV but may have been exposed to HIV in a 3-day period.  

 PEP can be taken if you: 
– Had sex with someone who may
have HIV  
– Didn’t use a condom during sex or
experienced a broken condom
during sex 
– Shared needles  
PEP is for emergencies and won’t prevent a future HIV infection.  

PrEP isn’t an emergency pill and can’t protect against an HIV infection that may have already happened. If you feel like that you have been exposed to HIV, talk to a healthcare provider or go to the emergency room to get PEP.

When should PrEP and PEP be taken?


PrEP should be taken daily to fight against possible HIV exposure. It takes about 7 days to reach high levels of protection.  

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PEP should be taken within 72 hours (or 3 days), 1-2 times a day for at least 28 days (4 weeks) after possible exposure to help stop HIV from spreading throughout your body.  While on PEP, continue to protect yourself and others by using condoms and not sharing needles.  
It shouldn’t be taken in place of HIV prevention – such as condom use, PrEP or not sharing needles. 

Before starting PrEP or PEP, visit a healthcare provider to get tested for HIV and Hepatitis B. If you were exposed to HIV through sex, you’ll get tested for other STIs, such as chlamydia, gonorrhea and syphilis. 

How effective is PrEP and PEP?


PrEP can lower your chances of getting HIV from sex by more than 90% and from sharing needles by more than 70%.  
It’s extremely important to take it daily or it won’t work as effective.


PEP isn’t 100% effective but the sooner you can start, the better it works.  
It’s important take every pill as directed and to not skip any doses.   

What are the side effects?

Both PrEP and PEP are very safe but may cause nausea, loss of appetite, and/or headaches. These side effects are not dangerous and usually get better with time. Most people don’t experience any side effects at all.  

If you have side effects that bother you and don’t go away, talk to a healthcare provider.  

Where can I get PrEP and PEP?


You can get PrEP from a local healthcare provider.


You may be able to get PEP from local health clinics but be sure to call first. If you’re not able to get it at a clinic, don’t wait. Go to the emergency room.  

What happens next?


Once on PrEP, you’ll follow-up with a healthcare provider at least every 3 months to get tested for HIV.  


Once you finish PEP, you will follow-up with a healthcare provider 4-6 weeks and 3 months after exposure to make sure PEP worked.  

Are you wondering if PrEP or PEP are right for you? Talk privately with a healthcare provider who can make a recommendation for you. Get started at