ellaOne® Product Information
ellaOne® is an emergency contraception tablet that contains 30mg of ulipristal acetate. It is a single-dose oral medication used to help prevent pregnancy after unprotected sex or after a regular contraceptive method has failed. ellaOne® can be taken at any point in the menstrual cycle and at any time of day, with or without food.
ellaOne® is licensed for use as emergency contraception within 120 hours (5 days) of unprotected sex or contraceptive failure. Examples of contraceptive failure include a condom that has split, come off or been used incorrectly, missed contraceptive pills, or a contraceptive patch or vaginal ring that has not been used correctly.
ellaOne® is intended for occasional use only and is not a substitute for a regular method of contraception.
ellaOne® contains ulipristal acetate, which is a selective progesterone receptor modulator. It works by attaching to the receptors that progesterone normally binds to, which delays or stops the release of an egg from the ovaries (ovulation). By delaying ovulation, ellaOne® can reduce the chance of sperm meeting an egg and fertilisation occurring.
ellaOne® does not interrupt an existing pregnancy and is not an abortion pill. It works mainly by delaying ovulation, so it may not work if ovulation has already happened.
Take one ellaOne® tablet by mouth as soon as possible after unprotected sex or contraceptive failure, and within a maximum of 120 hours (5 days). Swallow the tablet whole with water. The tablet can be taken at any time of day, before, during or after a meal. You can take ellaOne® at any point in your menstrual cycle.
If you vomit within 3 hours of taking ellaOne®, take another tablet as soon as possible, as the original dose may not have been fully absorbed.
ellaOne®: Our Pharmacist's Advice
"The single most important factor with any morning after pill is timing. ellaOne® works by delaying ovulation, which means it can only prevent pregnancy if it is taken before an egg is released. Because the timing of ovulation cannot be predicted reliably from one cycle to the next, taking ellaOne® as soon as possible after unprotected sex gives the best chance of it working, even within the licensed 120-hour window.
It is also important to be aware of the fact that ellaOne® will not protect you from an unplanned pregnancy for the rest of your cycle. ellaOne® only addresses the unprotected sex that has already happened. Until your next period arrives, a barrier method such as a condom should be used, and any regular hormonal contraceptive may be temporarily less reliable."
ellaOne® should be taken as soon as possible after unprotected sex. The sooner ellaOne® is taken, the better the chance of preventing pregnancy, as ulipristal acetate works by delaying ovulation. If ovulation is close to occurring or has already occurred, ellaOne® may not work. The timing of ovulation cannot be predicted, so taking the tablet without delay is important.
The active ingredient in ellaOne®, ulipristal acetate, has a half-life of approximately 32 hours. This means it takes about 32 hours for the level in your blood to be reduced by half. After a single dose, ulipristal acetate is expected to be reduced gradually over several days. However, ellaOne® does not provide ongoing contraceptive protection after it has been taken.
ellaOne® only provides protection for the unprotected sex that has already happened. It does not provide ongoing contraception, and any unprotected sex after taking ellaOne® can still lead to pregnancy.
No emergency contraceptive method is 100% successful at preventing pregnancy. In clinical studies, around 2 in 100 women became pregnant after taking ulipristal acetate for emergency contraception.
ellaOne® works best when taken as soon as possible after unprotected sex, and the chance of preventing pregnancy reduces as time passes between unprotected sex and taking the tablet.
ellaOne® can prevent pregnancy at any point up to 120 hours (5 days) after unprotected sex, but only if ovulation has not yet occurred.
No. ellaOne® works by delaying or postponing ovulation. If ovulation has already happened, ellaOne® cannot prevent pregnancy. Therefore, as the timing of ovulation cannot be reliably predicted, ellaOne® should be taken as soon as possible after unprotected sex.
If you think ovulation has already happened, or if more than 120 hours have passed since unprotected sex, you may wish to consider an alternative form of emergency contraception such as the copper intrauterine device (Cu-IUD), which can be fitted up to 5 days after unprotected sex or up to 5 days after the earliest expected date of ovulation. Speak to your GP or a sexual health clinic about your options.
Side effects, where they occur, can start soon after taking ellaOne® and usually settle within a few days. The most commonly reported side effects are headache, nausea, abdominal pain and period-like pain. These are not experienced by everyone.
If side effects persist for longer than a few days, or if you experience severe abdominal pain, heavy or unusual bleeding, or a missed period, speak to your GP for advice.
Yes, ellaOne® can delay your period, although the change is usually small. In approximately 7% of women, periods occur more than 7 days earlier than expected, and in approximately 18.5% of women, periods are delayed by more than 7 days. In about 4% of women, the delay is longer than 20 days.
If your period is more than 7 days late, is unusually light or heavy, or you have symptoms of pregnancy, take a pregnancy test and speak to your GP.
Some women experience irregular vaginal bleeding or spotting after taking ellaOne®. This can include light spotting, brown discharge or breakthrough bleeding before the next expected period. This is generally not a cause for concern, although the bleeding pattern after taking ellaOne® may differ from your usual cycle.
If you experience heavy or prolonged bleeding, severe abdominal pain or bleeding combined with a positive pregnancy test, speak to your GP as soon as possible, as pregnancy, including an ectopic pregnancy, should be ruled out.
Yes, no emergency contraceptive method is 100% successful. ellaOne® works by delaying ovulation. Therefore, if ovulation has already happened, the tablet cannot prevent pregnancy. ellaOne® may be less effective if it is not taken as soon as possible after unprotected sex, or if vomiting occurs within 3 hours of taking it, and another dose is not taken.
Take a pregnancy test if your next period is more than 7 days late or is unusually light or heavy, or if you have symptoms of pregnancy. Seek urgent medical attention if you experience severe abdominal pain after taking ellaOne®, as in rare cases this could be a sign of an ectopic pregnancy. The occurrence of bleeding does not rule out an ectopic pregnancy.
ellaOne® does not cause ectopic pregnancy. However, in any pregnancy that occurs after emergency contraception has been taken, the possibility of ectopic pregnancy should be considered, as with any pregnancy. This is particularly important if you have a history of ectopic pregnancy, fallopian tube surgery or a chronic genital infection.
Speak to your GP as soon as possible if you experience severe abdominal pain, shoulder tip pain, dizziness or unusual bleeding after taking ellaOne® and your period is delayed.
No. There is no evidence that ellaOne® affects long-term fertility. ellaOne® is intended for occasional emergency use and does not have lasting effects on your menstrual cycle or your ability to conceive in future cycles.
ellaOne® should not usually be taken more than once in the same menstrual cycle, as safety and effectiveness data for repeat use in the same cycle are limited.
If you have unprotected sex after taking ellaOne®, the tablet does not protect against the subsequent act of intercourse, and you may wish to consider a copper intrauterine device (Cu-IUD) as an alternative form of emergency contraception. Speak to your GP for advice.
No. ellaOne® and levonorgestrel-based emergency contraceptives (such as Levonelle or generic levonorgestrel) should not be taken together or within the same menstrual cycle. Levonorgestrel can interfere with the action of ulipristal acetate (the active ingredient in ellaOne®) and reduce the chance of either tablet preventing pregnancy.
After taking ellaOne®, you can start or continue a regular hormonal contraceptive method, such as the pill, patch, ring, implant or injection. However, ellaOne® may make hormonal contraception temporarily less effective, so you should use condoms every time you have sex until your next period.
ellaOne® and Levonelle (branded levonorgestrel) are both forms of emergency hormonal contraception, but they contain different active ingredients and have different windows of use:
- ellaOne® contains ulipristal acetate and can be taken up to 120 hours (5 days) after unprotected sex.
- Levonelle® and levonorgestrel contain levonorgestrel and can be taken up to 72 hours (3 days) after unprotected sex.
According to UK clinical guidance from the Faculty of Sexual and Reproductive Healthcare (now the College of Sexual and Reproductive Healthcare), ulipristal acetate is more likely to prevent pregnancy than levonorgestrel, particularly when unprotected sex has occurred between 96 and 120 hours earlier or when the user has a body mass index above 26. ellaOne® can also continue to delay ovulation even after the luteinising hormone (LH) surge has begun, while levonorgestrel becomes less suitable at this point in the cycle for preventing unplanned pregnancy.
Both medications work best when taken as soon as possible after unprotected sex. Ulipristal acetate and levonorgestrel should not be combined or taken within the same menstrual cycle.
There is no evidence that alcohol affects the action of ellaOne®. However, drinking alcohol may make some side effects, such as nausea, dizziness or vomiting, more likely. If you vomit within 3 hours of taking ellaOne®, take another tablet as soon as possible, as the original dose may not have been fully absorbed.
No. ellaOne® is a contraceptive used to prevent a pregnancy from starting. It will not interrupt or terminate an existing pregnancy. If your period is late, you have symptoms of pregnancy such as breast tenderness, nausea or morning sickness, speak to your GP or healthcare professional before taking ellaOne®. A pregnancy test may be advised first.
If you do become pregnant after taking ellaOne®, there is no evidence that the medication will harm the pregnancy. However, you should see your doctor for a check-up to rule out an ectopic pregnancy.
The active ingredient in ellaOne® is ulipristal acetate. Each film-coated tablet contains 30mg of ulipristal acetate.
The other ingredients in the standard ellaOne® formulation are lactose monohydrate, povidone, croscarmellose sodium and magnesium stearate.
For full and current ingredient information, please refer to the patient information leaflet for ellaOne®.
ellaOne® is available from pharmacies in the UK without a prescription, after a short consultation with a pharmacist to confirm suitability. You can buy ellaOne® online from Pharmica by completing a free online consultation, which is reviewed by our UK-registered pharmacist. Once approved, your order is dispatched in plain, discreet packaging with options for next-day or same-day delivery.
ellaOne® Morning After Pill Overview
Common side effects, which can affect up to 1 in 10 individuals, include:
- Nausea and/or vomiting
- Dizziness
- Abdominal pain or discomfort
- Pelvic pain or discomfort
- Period pain
- Breast tenderness
- Headaches
- Muscular pain
- Back pain
- Fatigue
Less common side effects, which affect up to 1 in 100 individuals, include:
- Digestive symptoms, such as diarrhoea, excessive flatulence and/or heartburn
- Irregular vaginal bleeding, which can include heavy periods
- Vaginal irritation and/or discharge
- Changes in sex drive
- Hot flushes
- Changes in appetite
- Mood changes
- Skin inflammation and/or itching
- Fever
Reporting side effects
This is not a complete list of side effects. Always read the Patient Information Leaflet supplied with your medication.
You can report suspected side effects directly through the MHRA Yellow Card Scheme. You can also tell our team, who can report on your behalf.
Information Leaflet
Always read the patient information leaflet before commencing treatment.
Written and reviewed by our qualified team
Content last updated:
03 Jun 2026