The Effect of St. John's Wort Treatment on Finasteride Pharmacokinetics and Identification of New Phase I and Phase II Metabolites in Humans

January 2008

Anna Lundahl, Mikael Hedeland, Ulf Bondesson, Lars Knutson, Hans Lennernäs

finasteride St. John’s wort phase I metabolites phase II metabolites pharmacokinetics drug metabolism Propecia

TLDR St. John’s wort changes how finasteride works in the body, possibly affecting its effectiveness.

The study investigated the impact of St. John’s wort on the pharmacokinetics of finasteride and identified new phase I and phase II metabolites in humans. It was found that St. John’s wort significantly altered the pharmacokinetics of finasteride, potentially affecting its efficacy. The research also led to the discovery of new metabolites, which provided further insight into the metabolic pathways of finasteride. This study highlighted the importance of considering herbal supplements like St. John’s wort when evaluating drug interactions and their potential effects on drug metabolism.

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