In vivo detection of RPV metabolites, M1 through M4 (top) and M5 through M7 (bottom), in human plasma and urine. Samples were collected from clinical subjects on an RPV-based antiretroviral regimen. Plasma and urine were extracted with acetonitrile in preparation for UHPLC-MS/MS analysis. Metabolites were detected in SRM mode using the following transitions: 383→222 m/z (M1 and M2), 399→183 m/z (M3), 399→196 m/z (M4), 543→367 m/z (M5), 559→383 m/z (M6), and 575→399 m/z (M7). Data shown are representative of three individual participants.