Norethisterone acetateProduct ingredient for Norethisterone

Norethisterone, also known as norethindrone, is a synthetic progestational hormone belonging to the 19-nortestosterone-derived class of progestins.⁸ It is further classified as a second-generation progestin, along with levonorgestrel and its derivatives, and is the active form of several other progestins including norethynodrel and lynestrenol.⁸ Norethisterone mimics the actions of endogenous progesterone, albeit with a greater potency,⁵ and is used on its own or in combination with estrogen derivatives in a variety of applications including contraception and hormone replacement therapy.^14,15,16,19 First derived in 1951 in Mexico City, norethisterone was originally intended for use as a remedy for irregular menstruation and endometriosis, and was not marketed for use as an oral contraceptive until 1962.²¹