If you have taken a drug to prevent an HIV infection (PrEP or PEP), you are asked to wait three months from last use of the drug to donate blood. PrEP, or pre-exposure prophylaxis, involves taking a specific combination of medicines as a prevention method for people who are HIV negative and may be at risk of HIV infection. PEP, or post-exposure prophylaxis, is a short-term treatment started as soon as possible after a high-risk exposure to HIV. The three-month waiting period is required due to these drugs interfering with viral replication and thus possibly altering the performance of diagnostic and screening tests for HIV, including extending the window period prior to detectable infection or a delay in producing antibodies.
If you have ever taken a drug to treat an HIV infection, known as antiretroviral therapy or ART, you are deferred from blood donation indefinitely since antiretroviral drugs do not fully eliminate the virus from the body, and donated blood can potentially still transmit HIV infection to a transfusion recipient. Although studies have documented that undetectable still equals untransmissible for sexual transmission, this does not apply to transfusion transmission.
Blood donation eligibility requirements are determined by the U.S. Food and Drug Administration (FDA). The Red Cross, like all blood collectors in the U.S., is required to follow the eligibility guidelines by the FDA. Potential donors with questions about donation eligibility can visit our website at RedCrossBlood.org or call the Red Cross Donor and Client Support Center at 1-866-236-3276.