Drug information of Ulipristal


Ulipristal is a selective progesterone receptor modulator used for the purposes of emergency contraception and for the treatment of uterine fibroids. It is a derivative of 19-norprogesterone and has both antagonistic and partial agonist activity at the progesterone receptor.

Mechanism of effect

Selective progesterone receptor modulator with antagonistic and partial agonistic effects

When taken immediately before ovulation, postpones follicular rupture

It is thought that the primary mechanism of action for emergency contraception is inhibition or delay of ovulation; however, alterations to the endometrium that may affect implantation may also occur


Ulipristal is a selective, reversible progestin receptor modulator and its tissue targets include the uterus, cervix, ovaries, and hypothalamus. Ulipristal may act as an agonist or antagonist in the presence or absence of progesterone based on the tissue target. If given mid-follicular phase, development of the follicle growth is delayed and estradiol concentrations decrease. If given at the time when luteinizing hormone peaks, follicular rapture is delayed by several days. If given early-luteal phase, a decrease in endometrial thickness can be observed.

It also binds to glucocorticoid receptor, however compared to mifepristone (a progesterone receptor antagonist), ulipristal is more tolerable and has lower glucocorticoid activity and better binding affinity.


Protein binding: >94%

Half-life: 32hr (ulipristal); 27 hr (monodemethylated metabolite)

Peak serum time:1hr

Peak Plasma Concentration: 176 ng/mL

Metabolism: predominantly by CYP3A4 to active metabolite monodemethyl-ulipristal acetate

AUC: 548 ng•hr/mL

Drug indications

Use as emergency contraception after unprotected intercourse or possible contraceptive failure when administered within 120 hours (5 days) after unprotected intercourse or a known or suspected contraceptive failure.



Emergency Contraception

30 mg (1 tablet) PO as soon as possible (within 120 hr [5 days]) after unprotected intercourse or a known/suspected contraceptive failure

If vomiting occurs within 3 hr after the dose, consider repeating the regimen

Higher efficacy if administered within first 72 hr postcoitus


<18 year: Safety and efficacy not established

Drug contraindications


Known or suspected pregnancy

Side effects

Headache , nausea , vertigo , tiredness , Abdominal pain , Dysmenorrhea

Headache , Abdominal and upper abdominal pain , Nausea, Menstruation occurring ≥7 days than expected, Dysmenorrhea , Intermenstrual bleeding , Fatigue , Dizziness , Menstruation occuring ≥7 days earlier than expected

apalutamide, bosentan, butalbital, carbamazepine, cigarette smoking, colchicine, dexamethasone, edoxaban, efavirenz, eslicarbazepine acetate, etravirine, felbamate, fosphenytoin, griseofulvin, idelalisib, ivosidenib, mitotane, nevirapine, oxcarbazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, riociguat, smoking, st john's wort, tesamorelin, topiramate, venetoclax


Not indicated for termination of existing pregnancy

Consider possibility of ectopic pregnancy in women who become pregnant or complain of lower abdominal pain after taking ulipristal

Repeated use within the same menstrual cycle not recommended

Fertility following use

  • A rapid return of fertility is likely following treatment; therefore, routine contraception should be continued or initiated as soon as possible following use
  • After use of ulapristal, a reliable barrier method of contraception should be used with subsequent acts of intercourse that occur in that same menstrual cycle
  • Because ulapristal and the progestin component of hormonal contraceptives both bind to the progesterone receptor, using them together could reduce their contraceptive effect
  • After using ulapristal, if a woman wishes to use hormonal contraception, she should do so no sooner than 5 days after the intake of ella, and she should use a reliable barrier method until the next menstrual period

Effect on menses

  • After use of ulipristal, menses sometimes occur earlier or later than expected by a few days; if there is a delay in the onset of expected menses beyond 1 week, rule out pregnancy
  • 9% of women in clinical trials reported intermenstrual bleeding after use

Points of recommendation

  • This medicine will not end a pregnancy.
  • This medicine is not for regular use to prevent pregnancy.
  • Do not take this medicine (ulipristal tablets) more than one time in the same period (menstrual) cycle.
  • This medicine may not work for all people who use it. Talk with the doctor.
  • This medicine does not stop the spread of diseases like HIV or hepatitis that are passed through blood or having sex. Do not have any kind of sex without using a latex or polyurethane condom. Do not share needles or other things like toothbrushes or razors. Talk with your doctor.
  • Certain health problems could cause this medicine (ulipristal tablets) to not work as well. Be sure your doctor knows about all of your health problems.
  • If you have very bad lower belly pain 3 to 5 weeks after taking this medicine (ulipristal tablets), call your doctor right away.
  • If your period is delayed for more than 7 days, talk with your doctor.
  • Birth control pills and other hormone-based birth control may not work as well to prevent pregnancy. If you will be using hormone-based birth control, wait at least 5 days after taking this medicine (ulipristal tablets) before starting it. Use a barrier form of birth control like a condom with spermicide during this time and until your next menstrual period.
  • Take with or without food.
  • Take this medicine (ulipristal tablets) within 5 days after unprotected sex.
  • If you throw up within 3 hours of taking this medicine (ulipristal tablets), call your doctor.

Pregnancy level

Not assigned

Not assigned

Related drugs


Ask a Pharmacist

User's questions
    No comments yet.