Contact your primary care provider, or go to an emergency department or urgent care to start PEP if you think you’ve recently (within 72 hours) been exposed to HIV:

• during sex (for example, if the condom broke); or
• through sharing needles, syringes, or other equipment to inject drugs; or
• if you’ve been sexually assaulted.

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.

• PEP is given after a possible exposure to HIV.
• PEP is only one component of protecting yourself from HIV infection. In addition to PEP, other methods of protection are still recommended, including the use of condoms.
• PEP is not the right choice for people who may be exposed to HIV frequently.
• If you are at ongoing risk for HIV exposure, consider taking PrEP for HIV prevention. 

If taken within 72 hours after possible exposure, PEP is highly effective in preventing HIV. But to be safe, you should take other actions to protect your partners while you are taking PEP.  This includes always using condoms with sexual partners and not sharing needles, syringes, or other equipment to inject drugs.

PEP is very safe but may cause side effects like nausea for some people.