HIV 101: Understanding PrEP and PEP medicines.

What is PrEP?

PrEP, or pre-exposure prophylaxis, is a medicine for people at risk for HIV to prevent getting HIV from sex or injection drug use.

PrEP is highly effective at preventing HIV when taken as indicated. PrEP reduces the risk of getting HIV from sex by about 99% when taken as prescribed. PrEP is much less effective when it isn't taken consistently.

When should you take PrEP?

PrEP may benefit you if you test negative for HIV and:

• you are having frequent anal or vaginal sex in the past 6 months, and you:

• have a sexual partner with HIV (especially if the partner has an unknown or detectable viral load),

• have not been consistently using a condom, or

• have been diagnosed with an STD in the past 6 months.

Is PrEP Safe?

PrEP is safe. No significant health effects have been seen in people who are HIV-negative and have taken PrEP for up to 5 years.

Some people taking PrEP may have side effects, like nausea, diarrhea, headache, fatigue, and stomach pain. These side effects are usually not serious and go away over time. If you are taking PrEP, tell your health care provider if you have any side effect that bothers you or that does not go away.

And be aware: PrEP protects you against HIV but not against other sexually transmitted infections (STIs) or other types of infections. Combining PrEP with condoms will reduce your risk of getting other STIs.

What Is PEP?

PEP stands for Post-Exposure Prophylaxis. This medicine is given to those HIV negative people who may be at risk of infection. If a person has come in contact with the virus in any way, then this medicine works to protect him from infection.

The success rate is believed to be 98% if PEP medication is taken within 72 hours of exposure. The course of PEP medicine lasts only one month.

How Do You Know If You Need PEP?

PEP may be right for you if you are HIV-negative or don’t know your HIV status, and you think you may have been exposed to HIV in the last 72 hours:

• During sex (for example, you had a condom break with a partner of unknown HIV status or a partner with HIV who is not virally suppressed)

• Through shared needles, syringes, or other equipment used to inject drugs, or

• Through sexual assault

• The sooner you start PEP, the better. Every hour counts. If you’re prescribed PEP, you’ll need to take it daily for 28 days.

You will also need to return to your health care provider at certain times while taking PEP and after you finish taking it for HIV testing and other tests.

How Well Does PEP Work?

PEP is effective in preventing HIV infection when it’s taken correctly, but it’s not 100% effective. The sooner you start PEP after a possible HIV exposure, the better.

While taking PEP, it’s important to use other HIV prevention methods, such as using condoms the right way, every time you have sex.