Frequently Asked Questions

Q: If taking anti-HIV drugs has made your viral load undetectable (meaning that the virus isn't showing up on blood tests), can you still pass the virus to another person through sex?

You may have heard that having a low or undetectable viral load in the blood may lower the risk of infecting your sex partner. This appears to be true in general, but we don't know for sure, and we cannot say that it will be true for you or for any specific individual.

Keep in mind that a viral load test measures the amount of virus in your blood. But sexual partners are usually infected by virus in sexual fluids, such as semen or vaginal or anal secretions. Unfortunately, the viral load in these fluids can be high even when the viral load in blood is low.

Studies are under way in several countries to determine whether lowering blood viral load with drugs can reduce the risk of infecting sexual partners. Until the results are known in a few years, it's probably best to be careful and continue to use condoms during sex, no matter how low your viral load.