The best time to block HIV blocking drugs is 1-2 hours after high-risk behavior occurs, and the success rate of blocking is close to 100%, but blocking is usually effective within 24 hours.
HIV blockers work by cutting off the HIV replication process, preventing the virus from spreading from infected cells and infecting more cells. The earlier the HIV blocker is taken, the sooner the drug reaches the infection site to ensure an effective concentration of the drug before the virus spreads, and before the virus enters the bloodstream. the best blocking time for HIV blockers is within 2 hours, with a failure rate of less than 5%, after which the success rate decreases, but still has a high success rate within 72 hours.
It should be noted that if high-risk behavior occurs for more than 72 hours, the success rate of blockade by taking HIV blocking drugs at this time is usually small, and the virus may have already entered the bloodstream, and taking the drugs will only play an antiviral role. Therefore, it is important to take HIV blocking drugs as soon as possible after exposure occurs.