The emergency contraceptive pill (ECP) is a safe and effective way to prevent pregnancy after unprotected sex, contraceptive failure or a sexual assault. It is frequently referred to as “The Morning After Pill”; however, women do not need to wait till the morning after to take the ECP. The ECP should be taken as soon as possible after unprotected sex.
ECPs contain either levonorgestrel or ulipristal.
What is the ECP used for?
The ECP is used to prevent a pregnancy that may occur because of:
- Forgotten contraception or a missed oral contraceptive
- Failed contraception (for example, a condom broke, a diaphragm was dislodged, or the expulsion of an IUD or implant)
- Failed withdrawal
- Starting an oral contraceptive too late in your cycle
- A sexual assault or sex against your will.
The ECP is only effective if taken within the recommended time of having unprotected sex (see differences between ECPs below). ECPs should not be used as an ongoing method of birth control. Ulipristal should not be given more than once in the same menstrual cycle.
A copper IUD (ParaGard T 380A) inserted within 5 days of having unprotected sex may also be used as emergency contraception. The effectiveness rate of a copper IUD is up to 99% and it can be left in place for up to 10 years, providing long-term birth control. It works by decreasing sperm motility and viability and preventing the implantation of an egg.
What are the differences between ECPs?
ECPs contain either levonorgestrel or ulipristal.
Levonorgestrel-containing ECPs
- Should be taken as soon as possible but can be taken within 72 hours (3 days) of having sex. Some studies have shown moderate efficacy still exists if taken up to 120 hours (5 days) after unprotected sex; however, this is less than ulipristal.
- Usually taken as one tablet containing 1.5mg levonorgestrel. Some generic forms may contain two tablets of 750mcg which can both be taken at the same time or administration separated by 12 hours.
- Work by stopping or delaying the release of the egg from the ovary (ovulation).
- May also alter the lining of the uterus to prevent egg implantation or reduce the ability of the sperm to bind to an egg.
- May not work as well in women who weight more than 165 lbs (75 kg) or have a body mass index (BMI) of more than 25 kg/m2; however, this has not been totally confirmed.
- Can be obtained over-the-counter (OTC) without a prescription, identification or age restriction. Costs: OTC levonorgestrel ECPs $30-$60. Generic versions may be less expensive; ask your pharmacist.
Ulipristal-containing ECPs
- Should be taken as soon as possible but can be taken within 120 hours (5 days) of having sex.
- Taken as one tablet (30mg) of ulipristal.
- Prevents pregnancy by blocking the natural hormone progesterone from occupying its receptor site in the body. Inhibits or delays ovulation and may also alter the lining of the uterus, preventing implantation.
- After taking ulipristal, a woman should wait at least five days before starting any other hormonal birth control (such as birth control pills [oral contraceptives], injections, implants, skin patches, or vaginal rings). Condoms or diaphragms should be used instead.
- Ulipristal could potentially harm an unborn baby or cause birth defects and should not be used if a woman is already pregnant or thinks she might be pregnant.
- Should not be used by girls who have not yet started their periods or by postmenopausal women.
- Should not be given twice in the same menstrual cycle.
- Requires a prescription from a doctor unless a women lives in one of the following states, then she can obtain a prescription from a pharmacist: Alaska, California, Hawaii, Maine, Massachusetts, New Hampshire, New Mexico, Vermont, Washington.
- Cost: Approximately $50 plus prescription fee.
Are ECPs safe?
ECPs are generally safe because they are usually just taken as a single dose. The risk of side effects increases if more than one course of levonorgestrel is taken during the same menstrual cycle. Ulipristal should NOT be used more than once during a menstrual cycle. If a menstrual period is delayed by more than one week after taking an ECP, a woman should see her doctor.
ECPs are only effective if used before a pregnancy is established and will not end an already established pregnancy. Studies have shown the levonorgestrel-containing ECP does not increase the risk of birth defects in a fetus; however, there have been isolated reports of birth defects in women who had unknowingly been pregnant and taken ulipristal. If a woman’s period is more than one week late, or if she experiences genital pain or bleeding then she should see her doctor. A second dose of ulipristal should not be taken in the same menstrual cycle. Levonorgestrel and ulipristal-containing ECPs should not be used by women who are pregnant (or think they are pregnant). Ulipristal should not be used by women who are breastfeeding and levonorgestrel should only be taken by women who are breastfeeding on a doctor’s advice.
Ectopic pregnancies should be considered and investigated in women who develop lower abdominal pain within a few weeks of taking an ECP. Taking an ECP has not been shown to have an effect on a woman’s future fertility.
ECPs do not provide protection against HIV and other sexually transmitted infections (STIs). See your doctor if you think you may have been exposed to an STI.
Ulipristal should not be taken with levonorgestrel-containing ECPs because it may lower the effectiveness. Other hormonal contraception (such as the pill which is taken daily) should not be taken for at least five days after taking ulipristal. Instead, a barrier contraception (such as condoms) should be used until menstruation occurs.
Some drugs or herbal products may decrease the effectiveness of ECPs.
For a complete list of severe side effects, please refer to the individual drug monographs.
What are the side effects of ECPs?
Emergency contraceptive pills are very safe to use. Side effects, if they occur at all, are usually short-term and mild and may include:
- Nausea
- Vomiting
- Irregular bleeding, spotting, heavier bleeding, delayed or early menstruation
- A headache
- Dizziness
- Breast tenderness
- Fatigue or tiredness
- Stomach pain or cramps.
You can ask your healthcare provider for anti-nausea medication if you feel sick or vomit. If vomiting occurs within 2 hours of taking a levonorgestrel-containing ECP or 3 hours of taking ulipristal contact your healthcare provider as a repeat dose may be needed.
For a complete list of side effects, please refer to the individual drug monographs.
For more information see Emergency Contraception and the Morning After Pill
The following list of medications are in some way related to or used in the treatment of this condition.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.