Media centre

Emergency contraception

Fact sheet N°244
July 2012

Key facts

  • Emergency contraception can prevent most pregnancies when taken after intercourse.
  • Emergency contraception can be used following unprotected intercourse, contraceptive failure, incorrect use of contraceptives, or in cases of sexual assault.
  • There are two methods of emergency contraception: emergency contraceptive pills (ECPs) and copper-bearing intrauterine devices (IUDs).
  • When inserted within five days of unprotected intercourse, a copper-bearing IUD is the most effective form of emergency contraception available.
  • The emergency contraceptive pill regimen recommended by WHO is one dose of levonorgestrel 1.5 mg, taken within five days (120 hours) of unprotected intercourse.

Emergency contraception, or post-coital contraception, refers to methods of contraception that can be used to prevent pregnancy in the first few days after intercourse. It is intended for emergency use following unprotected intercourse, contraceptive failure or misuse (such as forgotten pills or torn condoms), rape or coerced 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 contraceptive pills cannot interrupt an established pregnancy or harm a developing embryo.

Who needs emergency contraception?

Any woman of reproductive age may need emergency contraception at some point 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.

  • When no contraceptive has been used.
  • When there is a contraceptive failure or incorrect use, including:
    • condom breakage, slippage, or incorrect use;
    • three or more consecutively missed combined oral contraceptive pills;
    • the progestogen-only pill (minipill) taken more than three hours late (or more than 12 hours late if taking a 0.75mg desogestrel-containing pill);
    • norethisterone enanthate (NET-EN) progestogen-only injection taken more than two weeks late;
    • depot-medroxyprogesterone acetate (DMPA) progestogen-only injection taken more than four weeks late;
    • the combined estrogen-plus-progestogen monthly injection taken 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 periodic abstinence method, or failure to abstain or use a barrier method on the fertile days of the cycle;
    • expulsion of an intrauterine contraceptive device (IUD) or hormonal contraceptive implant.
  • In cases of sexual assault when the woman was not protected by an effective contraceptive method.

Methods of emergency contraception

There are two methods of emergency contraception:

  • emergency contraception pills (ECPs)
  • copper-bearing intrauterine devices (IUDs).

1. Emergency contraception pills

WHO recommends levonorgestrel for emergency contraceptive pill use. Ideally, this progestogen-only method should be taken as a single dose (1.5 mg) within five days (120 hours) of unprotected intercourse. Alternatively, a woman can take the levonorgestrel in two doses (0.75 mg each; 12 hours apart).

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.


Levonorgestrel-alone emergency contraception pills are very safe and do not cause abortion or harm future fertility. Side-effects 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. However, if a woman inadvertently takes the pills after she becomes pregnant, the available evidence suggests that the pills will not harm either the mother or her fetus.

Emergency contraceptive pills are for emergency use only and are not appropriate for regular use as an ongoing contraceptive method because of the higher possibility of failure compared with non-emergency contraceptives. In addition, frequent use of emergency contraception can result in side-effects such as menstrual irregularities, although their repeated use poses no known health risks.

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

2. Copper-bearing intrauterine devices (IUDs)

WHO recommends that a copper-bearing IUD, as an emergency contraceptive, be inserted within five days of unprotected intercourse. This may be an ideal emergency contraceptive for a woman who is hoping for an ongoing, highly effective contraceptive method.

Mode of action

As emergency contraception, the copper-bearing IUD primarily prevents fertilization by causing a chemical change that damages sperm and egg before they can meet.


When inserted within five 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 she may choose to change to another contraceptive method in the future.


A copper-bearing IUD is a very 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 if a woman is already pregnant. There are other contraindications to using a copper-bearing IUD as ongoing contraception, which also should be considered before its use as emergency contraception. For more information, please refer to the WHO Medical eligibility criteria for contraceptive use.

WHO response

WHO’s activities on emergency contraception form part of its work to provide access to high-quality services for family planning, particularly for the most vulnerable populations. This work is shaped by the WHO Global Reproductive Health Strategy.

In addition, through the UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), research is carried out that aims to provide the widest range of safe and effective family planning methods, as well as clinical research into novel methods or uses.

WHO reaffirms its commitment to keeping emerging evidence under close review through its Continuous Identification of Research Evidence (CIRE) system.


For more information contact:

WHO Media centre

Related documents

Related links