Prescrire Int. 1999 Dec;8(44):175-7.
(1) Mirena degrees is a contraceptive intrauterine device delivering levonorgestrel. (2) Its assessment is based on two prospective randomised multicenter trials comparing it to a copper device. (3) It is not known whether it is any more difficult to insert than other devices. (4) Efficacy, in terms of absolute protection and risk of extrauterine pregnancy, appears to be very good, at least equal to that of copper devices. (5) Women were less subject to menorrhagia than were women using a copper device. (6) In clinical trials up to a third of women had amenorrhoea. Some women had spotting during the first three months, and other adverse effects (e.g. acne, headache and mastodynia) were more frequent than among women using copper devices.