text: At low doses, levonorgestrel is used in monophasic and triphasic formulations of combined oral contraceptive pills, with available monophasic doses ranging from 100 to 250 µg, and triphasic doses of 50 µg/75 µg/125 µg. It is combined with the estrogen ethinylestradiol in these formulations.
  At very low daily dose of 30 µg, levonorgestrel is used in some progestogen-only pill formulations.
  Levonorgestrel is the active ingredient in a number of intrauterine devices including Mirena and Skyla. It is also the active ingredient in the birth control implants Norplant and Jadelle.
  One of the more common forms of contraception that contains only levonorgestrel is an IUD. One IUD, the Mirena, is a small hollow cylinder containing levonorgestrel and polydimethylsiloxane and covered with a release rate controlling membrane.