Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction Is unlikely. Black cohosh does not appear to be a potent modulator of human drug metabolism. Standardized black cohosh supplements, when taken at recommended doses, pose little risk for herb-drug interactions. Tenofovir alafenamide is metabolised to tenofovir (major metabolite) by carboxylesterase-1 and cathepsin A, with no CYP metabolism described.