title: Long-term reversible contraception with levonorgestrel-releasing Silastic rods.
mesh_terms: D004343:Drug Implants; D005260:Female; D006801:Humans; D009644:Norgestrel / Q000008:administration & dosage*; D012826:Silicone Elastomers
chemical_list: D004343:Drug Implants; D012826:Silicone Elastomers; D009644:Norgestrel