Will patients gain weight with Mirena?
Q - Is Mirena likely to cause weight gain? Should it be used in women with potential impaired glucose tolerance?
A - Several studies have assessed the effects of Mirena on weight and metabolism. None of these found any significant change in weight with Mirena compared with controls using non-hormonal methods of contraception.
This is consistent with the fact that Mirena provides very low, steady levels of levonorgestrel. Studies examining the effects of the progestogen only pill (POP) on carbohydrate metabolism are mainly reassuring.
The POP provides three to four times higher serum progestogen levels than Mirena: yet studies suggest the POP has no effect on glucose tolerance in women predisposed to diabetes and minimal effects on insulin dose requirements in diabetics.
Mirena provides safe, effective contraception with many potential non-contraceptive benefits. It has no overall effect on body weight or carbohydrate metabolism and can therefore safely be offered to women at risk of impaired glucose tolerance. Indeed, the very low serum progestogen levels with Mirena produce minimal metabolic effects compared with other available hormonal contraceptives.
As with all hormonal medications it is possible that a small number of women will gain an unacceptable amount of weight.
Dr Jo Power is specialist registrar in community gynaecology and reproductive health at the
Margaret Pyke Centre, London