Ulipristal acetate, sold under the brand name Ella among others, is a medication used for emergency contraception (birth control) and uterine fibroids.

[20] In January 2015 the European Commission issued an implementing decision amending accordingly the marketing authorization of EllaOne in the EU.

Ulipristal acetate is used for pre-operative treatment of moderate to severe symptoms of uterine fibroids in adult women of reproductive age.

[22] In November 2020, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommended that ulipristal acetate be used only to treat uterine fibroids in premenopausal women for whom surgical procedures (including uterine fibroid embolization) are not appropriate or have not worked.

[23] In addition, the committee stated that ulipristal acetate must not be used for controlling symptoms of uterine fibroids while awaiting surgical treatment.

[27] Volume reduction of uterine fibroid induced by ulipristal acetate was tentatively explained by the combination of multifactorial events involving control of proliferation of the tumor cells, induction of apoptosis and remodeling of the extracellular matrix[28] under the action of matrix metalloproteinases.

[30] A 2025 preliminary clinical study on 133 pregnant women indicated the possibility that ulipristal acetate, at a substantially higher dose than used for contraception and combined with misoprostol, could be used as a more widely available and similarly effective substitute for the abortifacient mifepristone.

[35]: 33, 43 It is also not recommended for women with severe asthma receiving glucocorticoid treatment because it has shown antiglucocorticoid effects in animal studies.

[36] However, data on embryotoxicity in humans are very limited, and it is not clear what the risk for an abortion or for teratogenicity (birth defects) is.

Ulipristal acetate is likely to interact with substrates of CYP3A4, like rifampicin, phenytoin, St John's wort, carbamazepine or ritonavir, therefore concomitant use with these agents is not recommended.

Ulipristal acetate exhibits similar potency to antagonize progesterone receptor as mifepristone in vitro.