Safety data on ulipristal acetate are limited, but most adverse effects seem mild or moderate and resolve on their own.

• As yet there is little postmarketing experience with ulipristal acetate. It is a black triangle product, so all suspected adverse reactions should be reported to the Medicines and Healthcare products Regulatory Agency (MHRA) using the Yellow Card Reporting scheme.
• In one single arm, open-label study, undertaken to determine the efficacy of a single 30 mg dose of ulipristal acetate (n = 1533) [EMEA, 2009], the most common adverse effects reported were:
• Headaches (17% of women), nausea (12.2%) and abdominal pain (11.7%).
• Less common adverse effects were infections, mood disorders, headache, dizziness, nausea, vomiting, dyspepsia, muscle spasms, back pain, dysmenorrhoea, menorrhagia, metrorrhagia and fatigue (between 1 in 100 women and 1 in 10 women).
• No serious adverse reactions were reported in the study and no subjects were discontinued from the study due to adverse reactions.
• In the same study, about 80% of women taking ulipristal acetate had their next period at the expected time or within 7 days.
• 6.1% experienced menses more than 7 days earlier than expected.
• 19.2% had a delay of more than 7 days beyond the anticipated onset of menses. This delay was more than 20 days in 5.1% of these women and more than 60 days in 0.5% of these women.
• Menstrual volume was reported as normal in 79% of the women in the study, 16% reported it as heavy, 5% as spotting.
• Very few women (8.7%) reported intermenstrual bleeding lasting an average of 2 days. The majority of these women (92%) reported the bleeding as spotting. Five women in the study reported a heavy intermenstrual bleed.