Two of the 8 BUVSs (UV-328 and UV-P) showed altered toxicity upon metabolism. UV-328 showed more potent antiandrogenic activity after CYP3A4-mediated metabolism. UV-328 can be metabolized into mono- and di-hydroxylated (OH) metabolites. Sites of metabolism of UV-328 occur mainly at the alicyclic hydrocarbon atom. Hydroxylation of BUVSs may present risk concern to human health.