You may have heard that having a low or undetectable viral load in the blood may lower the risk of infecting your sexual partner. But we don't know that for sure.

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 secretions. Unfortunately, the viral load in these fluids can be high even when the viral load in blood is low.

A very large study is being conducted in several countries to determine whether lowering blood viral load with drugs can reduce the risk of infecting sexual partners. Until the results of that study 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 is.