How long after starting PrEP do I need to wait before I will be protected HIV?

How Long Before Truvada Will Protect Me Against HIV Infection?

When you start taking PrEP, it takes a little while for the concentrations of the drug to get higher in the blood but also in the tissues of the body. For gay men, it’s around about seven days that you need to be taking the drug before it’s able to offer full protection. In women and trans men, you do need to be taking the drug for up to 21 days before you are offered full protection against HIV.