Pre-Exposure Prophylaxis (PrEP)

PrEP, short for pre-exposure prophylaxis, is medication that can prevent you from getting HIV if you take it before you’re exposed. It comes in pill form or as injections (shots).

You might consider taking PrEP if you don’t have HIV and you’re at a higher risk of exposure to it. You’re at a higher risk if you:

• Have sex with someone who has HIV or whose HIV status you don’t know
• Share needles or injection equipment with someone who has HIV or whose status you don’t know

You may also consider using PrEP if you’re at risk and you’re pregnant or you’re considering getting pregnant. It may protect the fetus from the virus during pregnancy. It may also protect the baby during breastfeeding.

PrEP isn’t for people who have HIV. If you don’t have HIV and have been exposed, see a healthcare provider right away about post-exposure prophylaxis (PEP). You don’t need PEP if you’re taking PrEP.

The term “pre-exposure prophylaxis” can also refer to any treatment you get before being exposed to an illness. It reduces your likelihood of getting sick.

How does PrEP work?

PrEP uses medications that fight HIV (antiretrovirals). If the virus gets into your body, the medicine fights off the infection before it can make you sick.

Types

Pre-exposure prophylaxis is available as a daily pill and long-lasting injections (shots). Some countries also have an “on-demand” pill option. Not every type is approved for everyone or every kind of exposure. Your healthcare provider can help you decide which is right for your specific situation.

Continuous pills

You take these pills every day. They’re a good option for people who can remember to take a daily pill and have frequent or unpredictable exposure to HIV. Options include:

• Truvada® (emtricitabine/tenofovir disoproxil fumarate): Truvada is approved for anyone at risk of HIV through sex or injected drug use.
• Descovy® (emtricitabine/tenofovir alafenamide): Descovy is approved for some people at risk of HIV through sex. It’s not approved for those at risk from receptive vaginal sex.

Injections

Injections give you longer-lasting protection than pills, so you need them less frequently. They’re for people who are at risk of HIV exposure through sex. You must weigh over 77 pounds to be eligible for injections. You have to go to a doctor’s office to get them.

Options include:

• Apretude® (cabotegravir): After the first two shots, you get injections every eight weeks. You’ll take a lead-in dose of oral cabotegravir before starting injections. You get the injections in the muscles of your butt.
• Yeztugo® (lenacapavir): This is two shots every six months. The first two days, you’ll also take two pills. You get the injections under your skin, usually in your belly.

On-demand pills

You may hear about “on-demand” PrEP, where pills are taken around the time of sex instead of daily. This approach is not FDA-approved in the U.S. and isn’t recommended by the Centers for Disease Control and Prevention (CDC). If you’ve heard about it and have questions, talk with your healthcare provider about approved options.

What do I have to do before getting PrEP?

Before starting PrEP, you’ll meet with a healthcare provider. They’ll talk to you about risk factors for HIV and medication options. Be sure to tell your provider about any health conditions you have and any other medications you’re taking, including vitamins and supplements.

Your provider will also take a sample of your blood to test for HIV and other infections. You’ll get follow-up HIV tests every two to three months while you’re on PrEP.

How effective is PrEP?

PrEP is about 99% effective at preventing HIV infections from sex when taken as prescribed. It’s at least 74% effective at preventing HIV infections from injected drug use.

What are the risks?

PrEP is very effective at preventing HIV if taken as prescribed. But there’s still a risk you could develop HIV while taking it, especially if you miss a dose.

PrEP doesn’t protect against other sexually transmitted infections or infections you can get from injecting drugs. That’s why getting PrEP will involve testing for other infections that you could be at risk of.

Other serious risks include:

• Allergic reactions
• Bone loss
• Kidney or liver damage
• Lactic acidosis, a buildup of lactic acid in your blood
• Mood changes, including depression or thoughts of suicide or self-harm

You also might have mild side effects. These could include:

• Diarrhea
• Dizziness
• Fatigue
• Headache
• Injection site pain, redness or irritation
• Injection site lumps or nodules
• Nausea
• Trouble sleeping