progestogen implant

Levonorgestrel implants, sold under the brandnames Norplant among others, is a type of contraceptive implant for birth control. It was developed by Sheldon J. Segal and Horatio B. Croxatto at the Population Council beginning in 1966, with the first clinical trial in Chile in 1974. It was first approved in Finland on November 23, 1983, where it was manufactured by Leiras Oy Pharmaceuticals. The original Norplant consisted of a set of six small (2.4 mm × 34 mm) silicone capsules, each filled with 36 mg of levonorgestrel (a progestin used in many birth control pills) implanted subdermally in the upper arm and effective for five years. The original (six capsule) Norplant's production has been phased out; USAID's contract ran until December 2006. The original (six capsule) Norplant was approved by the U.S. Food and Drug Administration (FDA) on December 10, 1990, and marketed in the United States in 1991 by Wyeth Pharmaceuticals. Norplant distribution in the United States ended in 2002; limited supplies still remained in the U.S. until 2004. Norplant was withdrawn from the UK market in 1999. Production of Norplant was discontinued globally in 2008.