Prep

Prep is a shorthand with several distinct meanings. In everyday language, it refers to preparation or preparatory work. In medicine, Prep or PrEP stands for pre-exposure prophylaxis, a preventive treatment designed to reduce the risk of acquiring HIV in people who are HIV-negative and at substantial risk.

Pre-exposure prophylaxis uses antiretroviral medications taken before or during potential exposure to HIV. The standard regimens include daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC), sold as Truvada, and, in some regions, another formulation of tenofovir alafenamide/emtricitabine (TAF/FTC), sold as Descovy, which is not approved for receptive vaginal sex. An event-driven (2-1-1) dosing option exists in select populations under specific guidelines. Initiation requires HIV testing to confirm negative status and baseline safety labs.

Effectiveness depends on adherence. When used consistently, PrEP substantially reduces the risk of sexually acquired HIV, with studies showing high protection with daily use; lower protection is possible with inconsistent use. PrEP is also effective for people who inject drugs. It does not protect against other sexually transmitted infections, and it does not treat existing HIV infection. Regular medical follow-up is required, including HIV testing and monitoring kidney function and bone health.

Access varies by country and healthcare systems. Costs, stigma, and access to regular clinic visits affect uptake. In many places, PrEP is part of broader HIV prevention strategies and is offered alongside condoms, regular testing, and other prevention measures.

Aside from the medical term, prep denotes general preparation and is used in education and everyday language. In some professional settings, preparatory work refers to activities conducted in advance of a task or event.