This belongs to the group of medicines known as progestogens. Norethisterone and its acetate and enantate esters are progestogens derived from nortestosterone that have weak oestrogenic and androgenic properties. They are commonly used as hormonal contraceptives. Norethisterone (Acetate, Heptanoate) was the first highly active oral progestational agent to be synthesized and to achieved widespread use. It was patented in 1951. it is prepared by chemical synthesis from precursors obtained from the Mexican yam. it is available in combination preparations. Chemically it(17a)-17-hydroxy-19-norpregn-4-en-20-yn-3-one. Norethisterone acetate is administered orally and Norethisterone enanthate is administered intramuscularly. itused for contraception and for the treatment of uterine bleeding.