At the start of a study, subjects will be administered low doses of a mixture of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam), and serial blood samples will be drawn and analyzed for the concentration of each drug over time. Afterwards, participants will take the red clover dietary supplement twice daily for 14 days to allow for potential inhibition or induction of drug metabolizing enzymes and transporters. Thereafter, the same drugs will be taken again to obtain a second measure of drug concentrations in blood over time. Changes in the concentration-time curve values for each probe drug obtained before and after ingestion of the supplement would indicate that metabolism of the probe drugs is impacted by the red clover dietary supplement.