When starting treatment for the first time, most people who are going to achieve an undetectable viral load will do so within 16 to 24 weeks. However, patients who start or change therapy with a high viral load may take longer to achieve viral suppression.

Some studies also indicate that people who experience a rapid drop in viral load soon after starting treatment tend to achieve better long-term outcomes. One research team, for example, found that the viral load level after four weeks of therapy strongly predicted the likelihood of achieving undetectable viral load with further treatment ^[1].

Much remains to be learned about the factors that influence HIV ‘dynamics’, or rate of viral load decline after starting therapy. Some data suggest that certain antiretroviral drugs may reduce viral load faster than others, and the same has been proposed for combination regimens that include a larger number of drugs.

At this time, however, the primary goal of most doctors when helping patients select a regimen is not reducing viral load as fast as possible, but rather getting it below 50 copies/ml within three to six months and keeping it suppressed as long as possible.