The only side effects reported by women using mifepristone/RU-486 plus prostaglandin for early abortion are similar to those of a spontaneous miscarriage - uterine cramps, bleeding, nausea, and fatigue. Mifepristone is as safe as aspiration abortion ; it is a non-invasive procedure and does not require anaesthesia. The implications are most dramatic for developing nations, where sanitary conditions for performing abortion are not often optimal. Conservative estimates form the World Health Organisation indicated that as many as 200,000 women die each year from complications of illegal abortions.

In one study, women used mifepristone as a postcoital contraceptive reported significantly less nausea, vomiting, headaches, and breast tenderness than did women who used the standard hormonal postcoital regimen. However, women who used mifepristone were more likely to experience a delay in the return of their menstrual period¹.