title: The once-a-year pill.
mesh_terms: D001695:Biology; D003267:Contraception; D004703:Endocrine System; D004739:England; D005193:Family Planning Services; D005860:Germany, West; D006728:Hormones; D010827:Physiology; D011374:Progesterone; D011372:Progestins
chemical_list: D006728:Hormones; D011372:Progestins; D011374:Progesterone
keywords: Biology; Contraception; Contraception Research; Contraceptive Implants; Contraceptive Methods; Endocrine System; England; Family Planning; Germany, Federal Republic Of; Hormones; Physiology; Progestational Hormones; Progesterone--administraction and dosage