ulipristal acetate at a glance
Medicine class
Selective progesterone receptor modulator and emergency contraceptive.
Administration
An oral film-coated tablet that may be taken with or without food and at any point in the menstrual cycle.
Ongoing protection
It does not protect against pregnancy from later sex or against sexually transmitted infections.
What is ulipristal acetate used for?
The selected UK products are licensed for:
Emergency contraception after unprotected sexual intercourse or contraceptive failure.
How does ulipristal acetate work?
Ulipristal acetate binds strongly to progesterone receptors and suppresses the luteinising-hormone surge, delaying or preventing release of an egg. It is not effective once ovulation has already occurred and does not disrupt an implanted pregnancy.
ulipristal acetate preparations and strengths
Tablet
Route: Oral
Strengths: 5 mg, 30 mg
How to take ulipristal acetate
Follow the instructions supplied by the pharmacist, prescriber or sexual-health service.
Swallow the film-coated tablet by mouth.
It can be taken with or without food.
If vomiting occurs within three hours, contact a pharmacist or sexual-health service promptly because replacement treatment may be needed.
Use reliable barrier contraception after taking it because later sex is not covered.
ulipristal acetate side effects
Common or expected effects
- Headache
- Nausea or vomiting
- Abdominal discomfort or pain
- Period-like pain or pelvic pain
- Dizziness
- Breast tenderness
- Fatigue
- A period that comes earlier or later than expected
Get urgent medical advice
- Swelling of the face, lips, tongue or throat, hives or breathing difficulty may indicate a serious allergic reaction.
- Severe lower abdominal pain, fainting or unusual bleeding when pregnancy is possible needs urgent assessment for ectopic pregnancy.
ulipristal acetate in pregnancy
Ulipristal acetate emergency contraception is not intended for someone known or suspected to be pregnant, and it will not end an existing pregnancy. Limited human exposure data have not identified a safety concern, but anyone who becomes pregnant after taking it should contact a healthcare professional, particularly if there is pain or bleeding.
ulipristal acetate while breastfeeding
Selected product information advises interrupting breastfeeding for one week and expressing and discarding milk. UK SPS guidance concludes that interruption is not considered necessary after one-off emergency-contraception use, although levonorgestrel or a copper IUD is preferred when clinically appropriate. Discuss the options with a pharmacist or clinician, especially if the infant is premature or unwell.
ulipristal acetate interactions
Check all prescribed, non-prescribed and herbal products before supply because some can reduce contraceptive effectiveness.
CYP3A4 enzyme inducers, including carbamazepine, phenytoin, phenobarbital, primidone, oxcarbazepine, rifampicin, rifabutin, griseofulvin, efavirenz, nevirapine and St John’s wort
These can substantially reduce ulipristal exposure and effectiveness; a non-hormonal emergency-contraception option should be considered.
Long-term ritonavir
Its enzyme-inducing effect may reduce ulipristal concentrations and effectiveness.
Common questions about ulipristal acetate
Answers are fully visible for fast scanning and source review.
What is ulipristal acetate used for?
The selected UK products are used as oral emergency contraception after unprotected sex or contraceptive failure.
Does ulipristal acetate cause an abortion?
No. It delays or prevents ovulation and does not end an existing pregnancy.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.