A number of other hydroxylated metabolites are also formed (6α-, 6β-, 7α-, 12β-, 15α-, 15β-, 16α, and 16β-hydroxyestradiol). Estradiol may also be metabolized to hydroxyestrones, such as 2-, 4-, and 16α-hydroxyestrone.
References
Goodman & Gilman's: The Pharmacological Basis of Therapeutics, 12e, 2011 > Estrogens and Progestins. Laurence L. Brunton, Bruce A. Chabner, Björn C. Knollmann.