The Sound of Evolution
Norelgestromin
Mechanism of action:
Norelgestromin is a synthetic progestin and a derivative of 19-nortestosterone. Norelgestromin suppresses the hypothalamic-pituitary-gonadal axis through negative feedback, reducing the luteinizing hormone (LH) surge and preventing normal follicular rupture, thereby inhibiting or delaying ovulation. Norelgestromin also thickens cervical mucus, making it more difficult for sperm to pass through the cervix into the uterine cavity and reducing the likelihood of fertilization. In addition, norelgestromin keeps the endometrium in a thin, non-proliferative state, which makes embryo implantation less favorable even if fertilization occurs.
Reference(s):
1. Goa KL et al. (2003). Transdermal ethinylestradiol/norelgestromin: a review of its use in hormonal contraception. Treat Endocrinol.
2. Henzl MR et al. (2001). Norgestimate. From the laboratory to three clinical indications. J Reprod Med.
3. Abrams LS et al. (2001). Pharmacokinetics of norelgestromin and ethinyl estradiol from two consecutive contraceptive patches. J Clin Pharmacol.