Pharmacology Endocrinology a8ebf9b1 All of the following are natural estrogens EXCEPT: A Estradiol B Ethinylestradiol C Estriol D Estrone High-Yield Explanation Ethinylestradiol is a synthetic steroidal estrogen. All others are natural estrogens. (Ref.Essentials of medical pharmacology 7th edition page no.306)