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Emergency contraception

Fact sheet
February 2016

Key facts

  • Emergency contraception can prevent most pregnancies when taken after intercourse.
  • Emergency contraception can be used in the following situations: unprotected intercourse, contraceptive failure, incorrect use of contraceptives, or in cases of sexual assault.
  • There are 3 methods of emergency contraception: emergency contraceptive pills (ECPs), combined oral contraceptive pills or the Yuzpe method, and copper-bearing intrauterine devices (IUDs).
  • A copper-bearing IUD is the most effective form of emergency contraception available when inserted within 5 days of unprotected intercourse.
  • The emergency contraceptive pill regimen recommended by WHO is either:
    • 1 dose of levonorgestrel 1.5 mg, or 1 dose of ulipristal 30 mg, taken within 5 days (120 hours) of unprotected intercourse; or
    • 2 doses of combined oral contraceptive pills (also known as the Yuzpe regimen).

What is emergency contraception?

Emergency contraception, or post-coital contraception, refers to methods of contraception that can be used to prevent pregnancy in the first 5 days after sexual intercourse. It is intended for use following unprotected intercourse, contraceptive failure or misuse (such as forgotten pills, or breakage or slippage of condoms), rape or coerced unprotected sex.

Emergency contraception is effective only in the first few days following intercourse before the ovum is released from the ovary and before the sperm fertilizes the ovum. Emergency contraception cannot interrupt an established pregnancy or harm a developing embryo.

Who needs emergency contraception?

Any woman or girl of reproductive age may need emergency contraception to avoid an unwanted pregnancy.

In what situations should emergency contraception be used?

Emergency contraception can be used in a number of situations following sexual intercourse. These include:

  • When no contraceptive has been used.
  • In cases of rape or coerced sex when the woman was not protected by an effective contraceptive method.
  • When there is a contraceptive failure or incorrect use, including:
    • condom breakage, slippage, or incorrect use;
    • 3 or more consecutively missed combined oral contraceptive pills;
    • progestogen-only pill (minipill) taken more than 3 hours late;
    • desogestrel-containing pill (0.75 mg) taken more than 12 hours late;
    • norethisterone enanthate (NET-EN) progestogen-only injection taken more than 2 weeks late;
    • depot-medroxyprogesterone acetate (DMPA) progestogen-only injection taken more than four weeks late;
    • the combined estrogen-plus-progestogen monthly injection given more than seven days late;
    • dislodgment, delay in placing, or early removal of a contraceptive hormonal ring or skin patch;
    • dislodgment, breakage, tearing, or early removal of a diaphragm or cervical cap;
    • failed withdrawal (e.g. ejaculation in the vagina or on external genitalia);
    • failure of a spermicide tablet or film to melt before intercourse;
    • miscalculation of the abstinence period, or failure to abstain or use a barrier method on the fertile days of the cycle when using fertility awareness based methods; and
    • expulsion of an intrauterine contraceptive device (IUD) or hormonal contraceptive implant.

Methods of emergency contraception

There are 3 methods of emergency contraception:

  • emergency contraception pills (ECPs)
  • combined oral contraceptive pills or the Yuzpe method
  • copper-bearing intrauterine devices (IUDs).

1. Emergency contraception pills

WHO recommends either of the following drugs for emergency contraception, for use within 5 days (120 hours) of unprotected sexual intercourse:

  • Levonorgestrel taken as a single dose (1.5 mg) Or alternatively, levonorgestrel taken in 2 doses (0.75 mg each, 12 hours apart).
  • Ulipristal acetate, taken as a single dose at 30 mg.
Mode of action

Levonorgestrel emergency contraceptive pills prevent pregnancy by preventing or delaying ovulation. They may also work to prevent fertilization of an egg by affecting the cervical mucus or the ability of sperm to bind to the egg.

Levonorgestrel emergency contraceptive pills are not effective once the process of implantation has begun, and they will not cause abortion.


Based on reports from nine studies including 10 500 women, the WHO-recommended levonorgestrel regimen is 52–94% effective in preventing pregnancy. The regimen is more effective the sooner after intercourse it is taken.

For ulipristal, evidence indicates that it prevents pregnancy in at least 98% of situations, especially if taken within 72 hours of sexual intercourse.


Levonorgestrel-alone emergency contraception pills are very safe and do not cause abortion or harm future fertility. Side-effects, generally similar to those experienced by women using oral contraceptive pills, are uncommon and generally mild.

Medical eligibility criteria and contraindications

Emergency contraceptive pills prevent pregnancy. They should not be given to a woman who already has a confirmed pregnancy. If a woman inadvertently takes the pills after she becomes pregnant, however, the available evidence suggests that the drugs will not harm either the mother or her fetus. These 2 drugs are not used for termination of pregnancy.

Emergency contraceptive pills are recommended for occasional use only after unprotected intercourse and are not recommended for regular use as an ongoing contraceptive method because of the higher possibility of failure compared with oral contraceptive pills. Frequent use of emergency contraception can result in increased side-effects, such as menstrual irregularities, although their repeated use poses no known health risks.

Emergency contraceptive pills may be less effective in obese women (body mass index more than 30 kg/m2) but there are no safety concerns. Obese women should not be denied access to emergency contraception when they need it.

There are no other medical contraindications to the use of levonorgestrel or ulipristal emergency contraception pills.

Counselling for use of emergency contraception should include options for using a regular contraception or additional information in case of perceived method failure.

2. The Yuzpe method

The Yuzpe method uses combined oral contraceptive pills. The pills are taken in 2 doses. Each dose must contain estrogen (100–120 mcg ethinyl estradiol) and progestin (0.50–0.60 mg levonorgestrel (LNG) or 1.0–1.2 mg norgestrel).

The first dose should be taken as soon as possible after unprotected intercourse (preferably within 72 hours but as late as 120 hours, or 5 days) and the second dose should be taken 12 hours later. If vomiting occurs within 2 hours of taking a dose, the dose should be repeated.

3. Copper-bearing intrauterine devices (IUDs)

WHO recommends that a copper-bearing IUD, when used as an emergency contraceptive method, be inserted within 5 days of unprotected intercourse. This method is particularly appropriate for a woman who would like to start using a highly effective, long-acting and reversible contraceptive method.

Mode of action

The copper-bearing IUD prevents fertilization by causing a chemical change in sperm and egg before they can meet.


When inserted within 5 days of unprotected intercourse, a copper-bearing IUD is over 99% effective in preventing pregnancy. This is the most effective form of emergency contraception available. Once inserted, the woman can continue to use the IUD as an ongoing method of contraception and may choose to change to another contraceptive method in the future.


A copper-bearing IUD is a safe form of emergency contraception. The risks of infection, expulsion or perforation are low.

Medical eligibility criteria and contraindications

The only situation in which a copper-bearing IUD should never be used as emergency contraception is when a woman is already pregnant.

Other contraindications to using a copper-bearing IUD as ongoing contraception should be considered before its use as emergency contraception. Some of these contraindications for initiation include severe thrombo-cytopenia, unexplained vaginal bleeding, cervical cancer, endometrial cancer and current Pelvic Inflammatory Disease (PID). For more information, please refer to the “WHO Medical eligibility criteria for contraceptive use.”

WHO recommendations for provision of emergency contraception

All women and girls at risk of an unintended pregnancy have a right to access emergency contraception and these methods should be routinely included within all national family planning programmes1. Moreover, emergency contraception should be integrated into health care services for populations most at risk of exposure to unprotected sex, including post-rape care and services for women and girls living in emergency and humanitarian settings.

The latest guidelines on which methods can be used by persons with certain health conditions are in the 5th edition of the "Medical eligibility criteria for contraceptive use":

WHO reaffirms its commitment to constantly reviewing emerging evidence through its Continuous Identification of Research Evidence (CIRE) system and also by regularly updating its guidance accordingly.