Emergency contraception

Emergency contraception can be used to prevent pregnancy after sex. This could happen:

  • if no contraception has been used
  • if a condom has broken
  • if a woman has been sexually assaulted

Emergency contraception does not prevent sexually transmissible infections.

Women who are sexually active are advised to talk with their local doctor, family planning clinic or sexual health clinic about reliable contraceptive methods and safer sexual behaviours. 

Source: Queensland Health1

   •   •   •

The Emergency Contraception Pill (ECP) can be used to prevent pregnancy after sex if:

  • contraception wasn’t used
  • a condom has broken during sex
  • a woman has been sexually assaulted.

The emergency contraceptive pill contains special doses of female hormones (progestogen and possibly oestrogen) and can prevent pregnancy in a couple of ways:

  • if ovulation has not already occurred, it can delay ovulation. This means a delay in the egg being released from the ovary, so fertilisation by the sperm can’t occur.
  • if an egg has already been released and fertilised by sperm, the pill can prevent the fertilised egg from implanting in the uterus. This means a pregnancy cannot develop.

When taken in the first 3 days after sex, the ECP prevents about 85% of expected pregnancies. However it may still be useful if taken up to 4 or 5 days after sex. Try and obtain it as soon as possible to have the best chance of it working.  Any woman can take emergency contraception, even those who cannot take other oral contraceptive pills. Side effects are minimal but may include nausea and vomiting. The timing of your next period could also change.

It doesn’t provide protection against sexually transmissible infections.

The emergency contraceptive pill can be bought over the counter at your local pharmacist or chemist, or through your local doctor, True Relationships & Reproductive Health or sexual health clinic.

Source: Queensland Government2

Introduction: Emergency contraception

Emergency contraception (Plan B One-Step or Next Choice. It is also called the "morning after pill.")

Emergency contraception keeps a woman from getting pregnant when she has had unprotected vaginal intercourse. "Unprotected" can mean that no method of birth control was used. It can also mean that a birth control method was used but it was used incorrectly, or did not work (like a condom breaking). Or, a woman may have forgotten to take her birth control pills. She also may have been abused or forced to have sex. These are just some of the reasons women may need emergency contraception.

Emergency contraception can be taken as a single pill treatment or in two doses. A single dose treatment works as well as two doses and does not have more side effects. It works by stopping the ovaries from releasing an egg or keeping the sperm from joining with the egg. For the best chances for it to work, take the pill as soon as possible after unprotected sex. It should be taken within 72 hours after having unprotected sex.

A single-pill dose or two-pill dose of emergency contraception is available over-the-counter (OTC) for women ages 17 and older.

Source: OWH (DHHS)3

Introduction: Emergency contraception

What is emergency contraception?

Emergency contraception, or emergency birth control, is used to help keep a woman from getting pregnant after she has had sex without using birth control or if the birth control method failed. If you are already pregnant, emergency contraception will not work.

Use emergency contraception if:

  • You didn't use birth control
  • You were forced to have sex
  • The condom broke or came off
  • Your diaphragm or cervical cap tears or slips out of place
  • You missed at least two or three active birth control pills in a row (depending on which pill brand you use)
  • You were more than two weeks late getting your birth control shot
  • Your patch or vaginal ring is placed too late, or is removed too soon
  • Your spermicide tablet doesn't melt before sex
  • Your IUD comes out
  • You use the natural family planning method and don't abstain from sex on the fertile days of your cycle
  • You have reason to think your regular birth control might have failed

Emergency contraception should not be used as regular birth control. Other birth control methods are much better at keeping women from becoming pregnant. Talk with your doctor to decide which one is right for you.

Source: OWH (DHHS)4

Types of Emergency contraception

Several methods of emergency contraception are available including the emergency contraceptive pill and the intrauterine contraceptive device (IUCD).

The emergency contraceptive pill (sometimes called the morning after pill) contains special doses of the female hormones oestrogen and progestogen. These hormones are used in different doses in oral contraceptive pills. The emergency contraceptive pill may be either oestrogen and progestogen together, or just progestogen alone. The tablets are taken in two doses, 12 hours apart.

Sometimes the intrauterine contraceptive device is also used as emergency contraception. This is a device inserted through the cervix into the uterus (womb) to provide long term contraception. It may not be suitable for some women. You can ask your doctor, sexual health service or family planning clinic for more information.

Any woman can take the emergency contraceptive pill. Women who cannot take the oral contraceptive pill are able to take the emergency contraceptive pill.

The emergency contraceptive pill (ECP) can prevent pregnancy in a couple of ways:

  • If ovulation has not already occurred, it can delay ovulation - this means a delay in the egg being released from the ovary, so fertilisation cannot occur.
  • If an egg has been released and has been fertilised by sperm, the ECP can prevent the fertilised egg from implanting in the uterus. This means a pregnancy cannot develop.

If a woman is already pregnant and that pregnancy is already planted into the uterus, ECP will have no effect on that pregnancy.

The risk of becoming pregnant after taking the ECP is between one and three per cent. That is, for every 100 women who use ECP following an episode of unprotected sex, between one and three will become pregnant. ECP is more reliable if it is taken within 12 hours of the episode of unprotected sex.

ECP is more likely to fail if:

  • it is more than three days since the episode of unprotected sex
  • if a woman has unprotected sex again before her next period
  • if a woman vomits after taking the ECP. 

Source: Queensland Health5

   •   •   •


  1. Source: Queensland Health: conditions.health.qld.gov.au/ HealthCondition/ condition/ 21/ 72/ 44/ emergency-contraception
  2. Source: Queensland Government: qld.gov.au/ health/ staying-healthy/ sexual-health/ contraception
  3. Source: OWH (DHHS): womenshealth.gov/ publications/ our-publications/ fact-sheet/ birth-control-methods.html
  4. Source: OWH (DHHS): womenshealth.gov/ publications/ our-publications/ fact-sheet/ emergency-contraception.html
  5. Source: Queensland Health: conditions.health.qld.gov.au/ HealthCondition/ condition/ 21/ 72/ 44/ emergency-contraception

   •   •   •

Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.