An oral contraceptive. A 4-year study of norethindrone.
D003267:Contraception; D003270:Contraceptive Agents; D003276:Contraceptives, Oral; D005260:Female; D006801:Humans; D009640:Norethindrone; D011374:Progesterone / Q000031:analogs & derivatives
D003270:Contraceptive Agents; D003276:Contraceptives, Oral; D011374:Progesterone; D009640:Norethindrone
CONTRACEPTIVES, ORAL; PROGESTERONE/related compounds