Reviewed by Dr Samantha Miller MB ChB
(2017, University of Glasgow)
GMC number: 7561464
Information last reviewed 26/03/2021
ellaOne is a type of emergency contraceptive used to prevent pregnancy after having unprotected sex. Often known as the morning after pill, it can be taken up to five days after having unprotected sex.
ellaOne works by delaying ovulation long enough for the sperm that have been deposited into your body during unprotected sex to die off. It contains the active substance ulipristal acetate which targets the progesterone receptor in the body that responds when progesterone is naturally released. During your menstrual cycle, an egg is released from the ovaries under the influence of specific hormones. ellaOne interferes with and delays this process to stop you from falling pregnant.
You can take ellaOne more than once in the same cycle, however, you should try to avoid regularly taking emergency contraceptives, as with regular use, you’re more likely to experience side effects, including disruption to your menstrual cycle. In addition, ellaOne has not been tested for long-term use, so there may be other more harmful side effects if you take ellaOne regularly. If you feel the need to take ellaOne more than once every month or two, you should consider other methods of contraception such as the pill, coil, or implant.
Due to the time pressure of the treatment, ellaOne is not suitable to order by post. The sooner you take the pill the more effective it is so we would not recommend putting it off and having to wait for your treatment to arrive. While it would be possible for Dr Felix to ship your order on next-day delivery, the risk of the package being lost or delayed would risk you not receiving effective treatment. However, you can order it in advance if you are going to be on holiday or are in a situation where you are unable to access contraception or emergency contraception easily.
In the UK, ellaOne is available from your GP or sexual health clinic for free. It’s also available from your pharmacy, however, there may be a charge. It may also be available from school nurses, A&E, walk-in centres or minor injuries.
ellaOne is effective at preventing pregnancy. The pregnancy rate in women taking ellaOne within 5 days of unprotected sex, is from 0.9–2.1%. This means that out of every 1000 women who take ellaOne after an episode of unprotected sex, between 9 and 21 would be expected to become pregnant. While you have a five-day window to take it after having unprotected sex, the sooner you take it the more effective it will be. Pregnancy occurs in less than 1% of women taking ellaOne within 24 hours.
Dose |
1 tablet, taken within 5 days of unprotected sexual intercourse |
Type of Medicine |
Emergency contraception |
Mechanism |
Inhibits or delays ovulation by suppressing luteinising hormone |
Available Size |
1 tablet |
Available Strengths |
30mg |
Active Ingredient |
Ulipristal acetate |
Price |
From £23.65 |
Side Effects |
Can include nausea, vomiting, stomach pain, breast tenderness, painful periods, pelvic pain, headache, dizziness, mood swings, tiredness, muscle pain |
The active ingredient in this medication is 30 milligrams ulipristal acetate.
The inactive ingredients are lactose monohydrate, povidone K30, croscarmellose sodium and magnesium stearate.
There are some possible side effects associated with ellaOne.
Common side effects (occur in 1/100 to 1/10 women):
Less common side effects (occur in 1/1,000 to 1/100 women):
Rare side effects (occur in 1/10,000 to 1/1,000) include:
Do not take ellaOne if there is a chance you are already pregnant. While you can take it at any time during your cycle if your period is already late then consult your doctor or pharmacist first. They may advise you to take a pregnancy test.
The emergency contraceptive is not suitable to take if you are allergic to any of the ingredients.
Consult your doctor if:
ellaOne does not act as a continual contraceptive. You'll need to use protection such as condoms or the pill if you have sexual intercourse after you take the medication. It also does not protect you against sexually transmitted infections.
Inform your doctor if you are taking:
ellaOne can cause hormonal forms of contraception, such as the combined pill, to become temporarily less effective. Therefore, if you wish to start or continue using hormonal contraception after taking ellaOne, you may be advised to use a reliable barrier method until the next menstrual period.
Drinking alcohol will not have an adverse effect on ellaOne.
If you take ellaOne while you are breastfeeding it's recommended that you stop breastfeeding for one week after taking the medication.
ellaOne does not have an effect on your fertility, other than temporarily preventing ovulation.
After taking ellaOne, your next menstrual period may arrive earlier or later than expected. If your period is late by seven days or more then the treatment may not have worked and you should take a pregnancy test.
Levonelle is another emergency contraceptive known as the morning-after pill. It must be taken within 72 hours of having unprotected sex and is most effective when taken within 24 hours. ellaOne is slightly more effective than Levonelle when used as directed; with ellaOne, 0.9–2.1% of women will become pregnant, whereas, with Levonelle, 0.6–3.1% will become pregnant. Levonelle has also been shown to be less effective for women with a larger BMI whereas ellaOne does not appear to be affected by weight. If you’ve recently been taking contraceptive pills, ellaOne may not be as effective, and Levonelle may be more suitable for you. Your prescriber will be able to advise you.
While ellaOne is the most effective morning after pill, the IUD is still the best form of emergency contraception. It can be inserted up to five days after unprotected sex and is over 99% effective, meaning that less than 1 in 1000 women will become pregnant if using the copper coil as an emergency contraceptive. It will also provide ongoing protection against pregnancy for up to ten years and does not interact with other medicines or interrupt sex.
A large study in 2014 concluded that the use of ellaOne does not increase the risk of ectopic pregnancy beyond that of the general population. Around 1% of pregnancies which occur after taking ellaOne are ectopic pregnancies.
If you vomit up to three hours after taking ellaOne then you'll need to take another tablet right away as the treatment may not have worked. If you continue to vomit, then seek advice from your doctor or pharmacist right away as they may issue you with an alternative.
While emergency contraception is never 100% effective, there are some factors that can make ellaOne less effective. The pill must be taken up to 120 hours after having unprotected sex, if you leave it too late then it won't work. Vomiting is another major factor as the side effects can include nausea and stomach upset. Discuss any medications you are taking with your doctor or pharmacist in case they interact with ellaOne and make them aware of any existing health conditions you may have to ensure the treatment is suitable for you.
Prices from:
We’re a fully regulated pharmacy, with qualified doctors and happy customers
Straightforward & efficient service. Easy to use & gives me peace of mind. Would thoroughly recommend. Thank you.
Patricia
Quick and discreet
Very good efficient service. No problems. I recommend Dr Felix highly.
Lucy