Pharmacology General 5f14e867 All of the following are natural estrogens except ? A Estradial B Ethinylestradiol C Estriol D Estrone High-Yield Explanation Ans. is 'b' i.e., Ethinylestradiol o Estradial, estrone and estrial, all three are found in blood, but estradiol is the most potent estrogen.