Influence of estrogen, progesterone and their synthetic derivatives on ovarian functions

Estrogen and progesterone, the main sex steroids mostly bound to plasma proteins while circulating in the bloodstream. Only unbound estrogen and progesterone are biologically active. Gonadotrophins like Luteinizing hormone (LH) and Follicle stimulating hormone (FSH) promote ovulation and stimulate secretion of the sex hormones-estrogen and progesterone from the ovaries. These sex steroids stimulate the target organs of the reproductive system and inhibit as well as around the time of ovulation stimulate gonadotropin secretion. Since estrogen circulating in the blood can negatively feed-back to reduce circulating levels of FSH and LH, most oral contraceptives contain a synthetic estrogen, along with a progestin. The present article overviews the role of estrogen, progesterone and their synthetic derivatives on ovarian functions. Keyword: Estrogen, Progesterone, Progestin, Ovary