title: Early oral contraceptive history: norethynodrel is not a prohormone.
authors.forename: R A
authors.initials: RA
authors.lastname: Edgren
mesh_terms: D003276:Contraceptives, Oral; D009641:Norethynodrel / Q000378:metabolism; D011498:Protein Precursors
chemical_list: D003276:Contraceptives, Oral; D011498:Protein Precursors; D009641:Norethynodrel