rod could be used to deliver drugs. In 1966 Dziuk and Cook published a study that looked at release rates and suggested that the rods could be well suited for contraception. After a study that used implants with progestogens for contraception, the Population Council developed and patented Norplant and Jadelle. Norplant has six rods and is considered a first-generation implant. Jadelle (Norplant II), a two-rod implant, and other single rod implants that followed, were developed because of complications resulting from Norplant's six-rod system. The Jadelle system contains two silicone rods mixed with levonorgestrel. In 1990 De Nijs patented a co-axial extrusion technique of ethylene vinylacetate copolymers and 3-keto-desogestrel (etonogestrel) for the preparation of long-acting contraceptive devices, such as Implanon, Nexplanon and Nuvaring. The single rods were less visible under the skin and used etonogestrel as opposed to levonorgestrel in the hopes that it would reduce side effects. Desogestrel (3-deketoetonogestrel), a prodrug of etonogestrel, was introduced for medical use in 1981. Norplant was used internationally beginning in 1983 and was marketed in the United States and the United Kingdom in 1993. There were many complications associated with Norplant removal in the United States and it was taken off the market in 2002. Although Jadelle was approved by the FDA, it has never been marketed in the United States, but it is widely used in Africa and Asia. Etonogestrel itself was first introduced as Implanon in Indonesia in 1998, was marketed in the United Kingdom shortly thereafter, and approved for use in the United States in 2006. Nexplanon was developed to eliminate the problem of non-insertion and localization of Implanon by changing the inserter device and making the rod radiopaque. As of January 2012, Implanon is no longer being marketed and Nexplanon is the only available single-rod implant. Society and culture Generic names Etonogestrel is the generic name of the drug and its , , and . It is also known by its developmental code name ORG-3236. Brand names Etonogestrel is marketed under the brand names Circlet, Implanon, Nexplanon, and NuvaRing. Availability Etonogestrel is available widely throughout the world, including in the United States, Canada, the United Kingdom, Ireland, elsewhere throughout Europe, South Africa, Latin America, South, East, and Southeast Asia, and elsewhere in the world. Research An etonogestrel-releasing intrauterine device was under development for use as a form of birth control for women but development was discontinued in 2015. Etonogestrel has