Selective modulator of progesterone receptors with slightly antagonistic effect on it.It is used on the treatment of uterine fibroids (Donnez 2012, Vázquez 2013) A high plasma protein-binding capacity explains its small passage (0.02 mg / L) into breastmilk observed at the first day (HRA Pharma 2015: 8.3). As an emergency contraceptive it is a medication of limited and occasional use. World Health Organization considers it compatible with breastfeeding on such cases. (WHO 2015). See specific info on "Ulipristal acetate (contraceptive)". On the treatment of fibroids, the issue of a possible increased risk is posed on long lasting treatments (one daily intake on cycles of 3 months each at a maximum of 4 cycles with a two-months resting period between cycles). Theoretically, the relative daily dose ingested by the infant would reach 1%, that is, on an each complete cycle (90 days) the infant would not even have been able to ingest the dose (weight-based) corresponding to one-day treatment.There are no published data on this medication related to breastfeeding, hence, a known safer alternative should be evaluated by following the best health caregiver knowledge.