Red Clover Botanical Dietary Supplements - Metabolism and Safety in Women

At the start of a study, subjects were administered low doses of a mixture of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam), and serial blood samples were drawn and analyzed for the concentration of each drug over time. Afterwards, participants took the red clover dietary supplement twice orally daily for 14 days to allow for potential inhibition or induction of drug metabolizing enzymes and transporters. Thereafter, the same drugs were 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 were evaluated to determine if metabolism of the probe drugs was impacted by the red clover dietary supplement.