Most potent estrogen is:

Ans. is 'b' i.e., Estradiol (E2)* The three major naturally occurring estrogens in women are estrone (El), estradiol (E2), and estriol (E3). Estradiol is the predominant estrogen during reproductive years both in terms of absolute serum levels as well as in terms of estrogenic activity.* During menopause, estrone is the predominant circulating estrogen and during pregnancy estriol is the predominant circulating estrogen in terms of serum levels. Though estriol is the most plentiful of the three estrogens it is also the weakest, whereas estradiol is the strongest with a potency of approximately 80 times that of estriol.* Thus, estradiol is the most important estrogen in non-pregnant females who are between the menarche and menopause stages of life.* However, during pregnancy this role shifts to estriol, and in postmenopausal women estrone becomes the primary form of estrogen in the body