16α-hydroxy Dehydroepiandrosterone is a metabolite of the endogenous steroid hormone dehydroepiandrosterone . 16α-hydroxy Dehydroepiandrosterone is formed from dehydroepiandrosterone via 16-hydroxylation by the cytochrome P450 (CYP) isoforms CYP3A4 and CYP3A5 in adult human liver microsomes, as well as by fetal recombinant CYP3A7. It is a precursor to fetal estrogens, including estriol .