Segesterone acetate, also known as Annovera, is a synthetic progestin derived from 19-norprogesterone. This drug is very potent; it mediates progestational activity 100 times higher than that of progesterone. It is used as a contraceptive but also as a treatment for endometriosis in South American countries. Segesterone acetate binds selectively to progesterone receptors. This drug differs from other contraceptives because it needs to be administered parenterally since it is rapidly metabolized in the liver. Segesterone acetate is not active when taken orally, but it is proved to be an anti-ovulatory agent when given in implants, vaginal rings, or percutaneous gel. This drug acts by binding as an agonist to the progesterone receptors in the hypothalamus, this causes the level of production of Gonadotropin hormone-releasing hormone (GnRH) to increase. This lower the transcription of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) in the pituitary gland. This prevents ovulation by blocking the midcycle surge in LH, resulting in the inhibition of ovarian follicles. This drug is administered as a vaginal ring that is releasing the hormone for 21 days. The cycle of 21 days can be repeated for 13 cycles. This vaginal ring also contains ethinyl estradiol.

Segesterone acetate Pathway References