The IUD with levonorgestrel was first approved for medical use in 1990 in Finland and in the United States in 2000.[5] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[6] The wholesale cost in the developing world is about US$122.46 each.[7] In the United Kingdom they cost the NHS about £88 pounds.[2] In the United States they cost around US$844.00.[8] More than 120 countries have approved the device and it is used by more than 10 million women.[5][9]