How effective is 3 days of PrEP? Three days of daily oral PrEP is not considered fully protective, especially for receptive vaginal sex. PrEP needs time to reach protective drug levels in different tissues. For anal sex, CDC estimates that Truvada reaches high protection after 7 days of daily use, with some data suggesting substantial levels after 4-7 days. For vaginal tissue and front-hole tissue, it takes about 20-21 days of daily use to reach maximum protective levels. Taking PrEP for only 3 days, then stopping, leaves gaps where drug levels are too low to block HIV. It is not a recommended schedule. There is a different evidence-based strategy called 2-1-1 or on-demand PrEP, which is only for cisgender men and transgender women who have anal sex and who do not have hepatitis B, using 2 pills 2-24 hours before sex, 1 pill 24 hours later, and 1 pill 48 hours later. Even that requires at least the double dose before exposure. For anyone looking at short-term protection, discuss timing and dosing with a clinician who can assess HIV risk, kidney function, and hepatitis B status.
1 votes
Marked as accepted