title: Circulating levels of norethindrone in women with a single silastic implant.
mesh_terms: D003274:Contraceptive Devices, Female; D004343:Drug Implants; D005260:Female; D006801:Humans; D008598:Menstruation / Q000187:drug effects; D009640:Norethindrone / Q000097:blood*; D012826:Silicone Elastomers
chemical_list: D004343:Drug Implants; D012826:Silicone Elastomers; D009640:Norethindrone