Premenopausal peripheral conversion of estrogen precursors in the obese patient results in the formation of:

In premenopausal adult women, most of the estrogen in the body is derived from ovarian secretion of estradiol, but a significant poion comes also from the extraglandular conversion of androstenedione to estrone. To a lesser extent, testosterone conversion to estradiol also contributes to the estrogen milieu. Muscle and adipose tissue are the major sites of aromatization. When there is an increase in fat cells, as in obese persons, estrogen levels will be higher, because adipose tissue exhibits a greater aromatization of androstenedione to estrone than does muscle.