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PrEP vs. PEP for HIV Prevention

PrEP vs. PEP for HIV Prevention Image

HIV prevention medications like PrEP and PEP have the potential to make a huge impact on the prevalence of the disease. When taken correctly, they can greatly reduce the risk of becoming infected with the virus. Learn more about these HIV prevention methods to find out whether one of them is a good fit for you.

What is PrEP?

PrEP stands for pre-exposure prophylaxis. It’s a medication (in the form of a daily pill) that you take in order to reduce your risk of infection with HIV.

PrEP works by blocking an enzyme called HIV reverse transcriptase, which in turn prevents HIV from making copies of itself in the body. When the virus can’t make enough copies in your system, you remain HIV-negative. PrEP only works when taken daily before exposure to HIV.

Who is PrEP For?

PrEP is for people who are HIV-negative and have a high risk of contracting HIV. This includes people who:

  • Are in an ongoing sexual relationship with an HIV-positive partner.
  • Do not regularly use condoms during sex with partners of unknown HIV status.
  • Have had anal sex without using a condom.
  • Have shared needles for injecting drugs.

PrEP may also help to protect you and your baby if you have a high risk for HIV and you’re pregnant, trying to get pregnant, or breastfeeding.

How to Take PrEP

When you start taking PrEP, it takes some time for it to become fully effective. It will protect you during receptive anal sex after about seven days. For insertive anal sex, vaginal sex, and injection drug use, you’ll be protected after about 20 days of taking PrEP.

You should take PrEP every day for as long as you’re at risk for getting HIV. Some people take it only during a specific relationship while others stay on it indefinitely. You can start and stop this medication at any time without any long-term side effects, but you should continue to take it for 30 days after your last possible exposure to the virus to maintain adequate protection.

PrEP is sometimes compared to taking a daily birth control pill like Lutera or Aviane to prevent pregnancy. When taken correctly, it’s very effective. In fact, studies show that PrEP is up to 99% effective in reducing the risk of getting HIV from sex. PrEP can also reduce the risk of HIV transmission from injecting drugs by more than 70% when used consistently.

What is PEP?

PEP stands for post-exposure prophylaxis. It’s a medication that you take after possible exposure to HIV in order to reduce your risk of infection.

PEP works by using antiretroviral therapy (ART) medications to stop HIV from spreading through the body.

Who Takes PEP?

PEP was originally used for health care workers exposed to HIV on the job. However, PEP is now also recommended for use after an HIV-negative person has unprotected sex, shares needles, or is sexually assaulted.

How to Take PEP

PEP needs to be taken within 72 hours after a possible exposure. The sooner you start, the better it works. You must take PEP every day for 28 days for it to be fully effective. You’ll need to visit a health care provider four to six weeks after the exposure to get a follow-up HIV test, along with another test about three months later.

While PrEP may be compared to birth control pills, you can think of PEP as being similar to emergency contraception. The major difference, of course, is that PEP involves a 28-day regimen rather than a single dose like Plan B One-Step or Ella.

How to Get PrEP and PEP

There are two PrEP medication approved by the FDA and available to those in the U.S.: Truvada and Descovy. You can get it with a prescription from a health care provider. To receive a prescription for PrEP online, check out the Nurx™ app. They’ll connect you with a licensed medical expert who can determine if this medication is a good fit for you, provide a prescription, and have the meds shipped directly to your home in a discreet package.

PEP can be obtained at an emergency room, doctor’s office, or health care clinic. It’s important to start taking it as soon as possible after a possible HIV exposure.

Because you must be HIV-negative to take PrEP and PEP, you must take an HIV test before receiving a prescription. If you want to keep taking PrEP, you’ll need to take repeat HIV tests every three months to make sure you’re still HIV-negative. If you use Nurx to get a PrEP prescription, you can get a self-test to screen for HIV without having to visit a doctor’s office.


This blog pro­vides infor­ma­tion about telemed­i­cine, health and related sub­jects. The blog content and any linked materials herein are not intended to be, and should not be con­strued as a substitute for, med­ical or healthcare advice, diagnosis or treatment. Any reader or per­son with a med­ical con­cern should con­sult with an appropriately-licensed physi­cian or other healthcare provider. This blog is provided purely for informational purposes. The views expressed herein are not sponsored by and do not represent the opinions of Nurx™.

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