Snapshot A 25-year-old graduate student presents to her local urgent care for emergency contraception. She reports she has been with her partner for many years, and they always use barrier contraception. However, last night the condom broke. She wonders if there is a time limit to when she can take a pill for emergency contraception. She is prescribed ulipristal. Introduction Drugs mifepristone ulipristal Mechanism of action antiprogestins via competitive inhibition of the progesterone receptor Clinical use termination of pregnancy mifepristone + misoprostol (PGE1 analog) emergency contraception ulipristal must be taken within 120 hours of unprotected sex with the highest efficacy if taken within 72 hours Adverse effects abdominal pain uterine cramping nausea and vomiting