text: <unk>  (or norethindrone) (or 19-nor-17α-ethynyltestosterone) is a molecule used in some combined oral contraceptive pills and in some progestogen only pills. It is a progestogen and can be used to treat premenstrual syndrome, painful periods, abnormal heavy bleeding, irregular periods, menopausal syndrome (in combination with oestrogen), or to postpone a period. Norethindrone was the first orally highly active progestin to be synthesized.  It was synthesized for the first time by chemists Luis E. Miramontes, Carl Djerassi, and George Rosenkranz at Syntex in Mexico City in 1951. It was the progestin used in one of the first two  oral contraceptives.  It is often used as the related ester,<unk>  acetate.
option_0: Norethisterone
option_1: Norethandrolone
option_2: Oxandrolone
option_3: Methandrostenolone
option_4: Ethisterone
option_5: Methylestrenolone
option_6: Ethylestrenol
option_7: Allylestrenol