Emergency contraception

Levonorgestrel, in the single-agent emergency contraceptive form, is indicated for the prevention of pregnancy after the confirmed or suspected failure of contraception methods or following unprotected intercourse. It is distributed by prescription for patients under 17, and over the counter for those above this age.18 This levonorgestrel-only form of contraception is not indicated for regular contraception and must be taken as soon as possible within 72 hours after intercourse.3,18 It has shown a lower efficacy when it is used off label within 96 hours.17

Long-term contraception or nonemergency contraception

In addition to the above indication in emergency contraception, levonorgestrel is combined with other contraceptives in contraceptive formulations designed for regular use, for example with ethinyl estradiol.19 It is used in various hormone-releasing intrauterine devices for long-term contraception ranging for a duration of 3-5 years.20,21,22 Product labeling for Mirena specifically mentions that it is recommended in women who have had at least 1 child.20 A subdermal implant is also available for the prevention of pregnancy for up to 5 years.28

Hormone therapy and off-label uses

Levonorgestrel is prescribed in combination with estradiol as hormone therapy during menopause to manage vasomotor symptoms and to prevent osteoporosis.26Off-label, levonorgestrel may be used to treat menorrhagia, endometrial hyperplasia, and endometriosis.17