Morning-after pill

The morning-after pill is a form of emergency contraception. It can lower the chance of pregnancy after sex without contraception or when contraception may not have worked. For example, a condom may have broken, or contraceptive pills may have been missed.

It is not a disease or a diagnosis. The name can also be misleading: you do not have to wait until the next morning. Emergency contraception usually works better when used as soon as possible.

There are two main types of emergency contraceptive pill:

• Levonorgestrel, a hormone similar to progesterone
• Ulipristal acetate, a medicine that changes how progesterone acts

Levonorgestrel products are generally intended to be taken within 72 hours of sex. Ulipristal can be taken within 120 hours, or five days. Evidence suggests levonorgestrel may still offer some benefit later than 72 hours, but it becomes less effective with time.

Access differs by country. Levonorgestrel may be available without a prescription, while ulipristal may require one.

A copper intrauterine device, or copper IUD, is another form of emergency contraception. It is a small device placed inside the uterus by a trained clinician. It is the most effective emergency contraception and can usually be fitted within five days of sex. It can then provide ongoing contraception.

Pregnancy does not begin immediately after sex. Sperm can remain able to fertilize an egg for several days.

The morning-after pill mainly works by delaying or preventing ovulation, which is the release of an egg from an ovary. If no egg is available while sperm are present, fertilization cannot happen.

Ulipristal can delay ovulation closer to the time when an egg would be released than levonorgestrel can. Neither pill is expected to work reliably after ovulation has already happened.

Emergency contraceptive pills do not end an established pregnancy. They are different from medicines used for abortion and do not stop a fertilized egg that has already implanted in the uterus.

A morning-after pill only addresses sex that happened before you took it. It does not protect against pregnancy from sex later in the same menstrual cycle.

Emergency contraception gives you a time-limited option after unprotected sex or contraceptive failure. Taking action promptly leaves more options open.

The choice between levonorgestrel, ulipristal and a copper IUD can be affected by:

• How long it has been since sex
• Whether there was unprotected sex more than once
• Your current medicines or supplements
• Your weight or body mass index
• Whether you want ongoing contraception
• Whether an IUD is suitable and available

Higher body weight may reduce the effectiveness of oral emergency contraception, particularly levonorgestrel. Ulipristal may be more effective than levonorgestrel in this situation, although its effectiveness may also be affected. A copper IUD remains the most effective option regardless of body weight.

Some medicines can reduce the amount of an emergency contraceptive pill in the body. These include certain treatments for epilepsy, tuberculosis or HIV, as well as the herbal product St John’s wort. A pharmacist or clinician can check for interactions.

Emergency contraception does not protect against sexually transmitted infections, or STIs. STI testing, preventive treatment or vaccination may be appropriate after some exposures.

The morning-after pill does not prevent every pregnancy. It may not work if ovulation has already happened, if it is taken too late, or if another medicine lowers its effect. Pregnancy is also possible after further unprotected sex later in the cycle.

Temporary effects can include nausea, headache, tiredness, dizziness, cramps or abdominal discomfort. Your next period may come earlier or later than expected, and bleeding may be lighter, heavier or more irregular. These changes often settle by the next cycle.

Vomiting soon after taking the tablet may prevent enough medicine from being absorbed. Contact a pharmacist or sexual health service promptly because another dose may be needed. The relevant time window differs between products.

Taking ulipristal and then restarting hormonal contraception too soon can make ulipristal less effective. Taking levonorgestrel and ulipristal together is also not advised because they may work against each other.

An emergency contraceptive pill will not treat an existing pregnancy, including an ectopic pregnancy. This is a pregnancy growing outside the uterus, usually in a fallopian tube. Ectopic pregnancy is uncommon but can become serious.

Seek urgent medical assessment if you develop significant or one-sided lower abdominal pain, especially after a positive pregnancy test. Call emergency services for severe pain, fainting, marked weakness, shoulder-tip pain or heavy bleeding.

Without those warning signs, a late period or positive pregnancy test usually needs prompt routine follow-up rather than emergency care.

If you need emergency contraception, contact a pharmacist, sexual health service or reproductive health clinician as soon as you can. Do not wait for a pregnancy test, because a test taken soon after sex cannot show whether that encounter caused a pregnancy.

Be ready to share:

• When the unprotected sex happened
• The first day of your last period
• Whether there were other episodes of unprotected sex
• The contraception you normally use
• Your medicines, supplements and herbal products

Ask which pill is likely to work best for your timing and circumstances. You can also ask whether a copper IUD is an option.

After levonorgestrel, regular hormonal contraception can usually be started or resumed immediately. Use condoms or avoid sex for seven days while it becomes effective.

After ulipristal, wait at least five days before starting or restarting hormonal contraception. Use condoms or avoid sex during that wait and for seven days after starting most hormonal methods. Instructions can differ for some methods, so check the product information or ask a pharmacist.

Take a home pregnancy test three weeks after the most recent unprotected sex if you have not had a normal period or withdrawal bleed. Test sooner if your period is more than a week late. Arrange routine follow-up if the result is positive, bleeding remains unusual or you are unsure about the result.

If the sex was not consensual, a sexual assault service can offer confidential medical care, STI support and help with personal safety. You can seek this care whether or not you report the assault.

Is the morning-after pill the same as an abortion pill?

No. Emergency contraceptive pills delay or prevent ovulation. They do not end an established pregnancy. Abortion medicines work in a different way after pregnancy has begun.

Will it affect my future fertility?

Emergency contraceptive pills do not delay the return of fertility. Pregnancy can occur later in the same cycle, which is why further contraception is needed.

Can I use it more than once?

Emergency contraception can be needed more than once, but the choice of product matters. In particular, using levonorgestrel and ulipristal close together may reduce effectiveness. Ask a pharmacist or sexual health service which option is appropriate.

Does it protect me for the rest of the month?

No. It does not protect against pregnancy from sex after the dose. Use condoms, avoid sex or begin an effective ongoing contraceptive method as directed.

Do I need a pregnancy test first?

Usually not. Testing before taking the pill may delay treatment and cannot detect a pregnancy caused by very recent sex. A later test is useful if your period does not arrive as expected.

What if I am breastfeeding?

The advice differs between levonorgestrel and ulipristal and may also differ by country. Tell the pharmacist or clinician that you are breastfeeding so they can check the current product guidance and discuss a copper IUD if appropriate.