Effectiveness depends on the user: Risk of pregnancy is greatest when a woman cannot fully or nearly fully breastfeed her infant.

• As commonly used, about 2 pregnancies per 100 women using LAM in the first 6 months after childbirth. This means that 98 of every 100 women relying on LAM will not become pregnant.
• When used correctly, less than 1 pregnancy per 100 women using LAM in the first 6 months after childbirth.

Return of fertility after LAM is stopped: Depends on how much the woman continues to breastfeed

Protection against sexually transmitted infections: None