There have been tremendous advances in the treatment of HIV by combining 3 to 4 of the 20 anti-HIV medications available. Despite these advances, there remain several important complications related to the treatment, most importantly adverse events like nausea, diarrhea, liver toxicity and lipodystrophy (fat wasting or accumulation). Some studies have found that drug levels are higher in women and that these higher drug levels are associated with the increased toxicity in women. The reasons for the higher drug levels remain unclear. It is unknown whether these relate to hormonal influences, drug metabolism, adherence, fat distribution, body size or other factors. For this reason, we would like to carry out this study to measure drug levels in HIV-infected women that are taking anti-HIV medications. This study will determine the predictors of high drug levels and will assess the association of drug levels and adverse events in women.