ellaOne Emergency Contraception "Morning After Pill"

Buy ellaOne Emergency Contraception

ellaOne is an emergency contraceptive pill, otherwise known as the ‘morning after pill’, that can prevent pregnancy if you've had unprotected sex or your contraception has failed. It contains the active ingredient ulipristal acetate, which works by delaying ovulation, therefore, not allowing a pregnancy to occur.

How quickly do you need to use the ellaOne morning after pill?

You need to take ellaOne within five days (120 hours) of unprotected sex. The sooner you take it, the better it works. When taken within 24 hours, ellaOne is around 98% to 99% effective, but that effectiveness drops the longer you wait.

How does ellaOne work?

ellaOne contains ulipristal acetate, which works by blocking the hormone progesterone. This delays or prevents ovulation (the release of an egg). If no egg is released, it can’t be fertilised by sperm, meaning pregnancy can’t occur.

This pill helps to prevent pregnancy from occurring. However, it won’t interrupt an existing pregnancy.

How long does ellaOne take to work?

ellaOne starts working as soon as you take it. There's no waiting period, which is why it's so important to take it as quickly as possible after unprotected sex.

How long does ellaOne stay in your system?

The active ingredient in ellaOne, ulipristal acetate, is processed by the liver and cleared from the body over several days. Because small amounts may pass into breast milk, you’re advised not to breastfeed for one week after taking ellaOne to avoid exposing it to your baby.

How effective is ellaOne?

ellaOne is one of the most effective emergency contraceptive pills available. When taken within 24 hours of unprotected sex, it's 98 to 99% effective. It can be taken up to five days after, but its effectiveness decreases the longer you wait, so acting quickly makes a difference.

To put that in context, the other emergency contraceptive pill, levonorgestrel (Levonelle), is around 95% effective within the first 24 hours. And while Levonelle may be less effective if you have a higher BMI (over 26) or weigh over 70kg, ellaOne is still recommended regardless of your weight or BMI.

A few things can affect how well ellaOne works:

• If you've already ovulated. ellaOne works by delaying ovulation, so if ovulation has already happened before you take it, it's unlikely to be effective.
• If you're sick. Vomiting within three hours of taking ellaOne means it may not have been fully absorbed. If this happens, take another tablet as soon as possible.
• Certain medications. Some medicines can reduce how well ellaOne works.

ellaOne only protects you against the single incident of unprotected sex for which it was taken. If you have unprotected sex again after taking it, you may need another dose, and you should use condoms until your next period.

How do you know ellaOne has worked?

The only way to know if ellaOne has worked is when your period arrives. It might come early, on time, or a few days late, and all of these are normal after taking emergency contraception.

If your period is more than a week late, take a pregnancy test. You should also take a test 21 days after you last had unprotected sex.

Some people experience side effects like nausea or headaches after taking ellaOne, but these aren't signs that it's worked. It's just your body responding to the hormones in the pill.

Does ellaOne work after ovulation?

ellaOne works by delaying ovulation, so it’s only effective when taken before ovulation occurs, not after. If you’re unsure where you are in your cycle, it’s still worth taking ellaOne as soon as possible, as you may not have ovulated yet.

How to use ellaOne

• Take one tablet by mouth as soon as possible, and no later than five days (120 hours) after unprotected sex.
• You can take it at any time in your cycle as long as it’s before ovulation, and at any time of day, whether that's before, during, or after a meal.
• If you're currently taking any medicines that could stop ellaOne from working properly, or if you've taken any of these in the past four weeks, speak to your GP or pharmacist before taking ellaOne.
• If you're sick within three hours of taking ellaOne, take another tablet as soon as possible. The first one may not have been properly absorbed.
• After taking ellaOne, use condoms every time you have sex until your next period ellaOne won't protect you from pregnancy if you have unprotected sex again after taking it.
• If you use hormonal contraception like the pill or patch, carry on taking it as normal after ellaOne, but use condoms as a backup until your next period.

ellaOne side effects

Like all medicines, ellaOne can cause side effects, though not everyone gets them. Common side effects may include (affecting up to one in 10 people):

• nausea
• vomiting
• stomach pain or discomfort
• headaches
• dizziness
• mood swings
• painful periods
• pelvic pain
• breast tenderness
• muscle pain
• back pain
• tiredness

As ellaOne can cause side effects that impact your vision and alertness, it’s important not to drive or operate machinery until you know how it affects you.

How long do ellaOne side effects last?

Most side effects from ellaOne are temporary and should settle within a few days. If you're worried about a side effect that's lasting longer than expected or feels severe, have a chat with your pharmacist or GP.

When not to use ellaOne emergency contraception

Don't take ellaOne if you're allergic to ulipristal acetate or any of the other listed ingredients. Talk to your GP or prescriber before taking ellaOne if:

• you think you might already be pregnant (for example, your period is late or you have pregnancy symptoms)
• you have severe asthma or severe liver disease
• you have breast or gynaecological cancer

ellaOne tablets and other medication

It's important to tell your pharmacist, GP, or another healthcare professional about any medicines you're currently taking or have recently taken, including anything bought without a prescription and herbal remedies.

ellaOne can temporarily make regular hormonal contraceptives like pills and patches less effective. If you're currently using hormonal contraception, carry on taking it as usual after ellaOne, but make sure you use condoms every time you have sex until your next period.

Don't take ellaOne at the same time as another emergency contraceptive pill containing levonorgestrel. Taking both together can make ellaOne less effective.

Some medicines can also stop ellaOne from working properly. If you've used any of the following in the last four weeks, ellaOne may be less suitable for you, and your doctor may recommend a non-hormonal alternative like a copper IUD instead.

Speak to your GP or pharmacist before taking ellaOne if you use or have recently used:

• epilepsy medicines like primidone, phenobarbital, phenytoin, fosphenytoin, carbamazepine, oxcarbazepine or barbiturates
• TB treatments like rifampicin or rifabutin
• HIV treatments like ritonavir, efavirenz or nevirapine
• the antifungal medicine griseofulvin
• herbal remedies containing St John's Wort

ellaOne and breastfeeding

If you're breastfeeding, you can still take ellaOne, but you should avoid breastfeeding for one week after taking it. During that week, use a breast pump to keep your milk supply going, but discard the milk.

The effect of ellaOne on breast milk and on your baby isn't fully understood, which is why this precaution is in place.

Can you drink alcohol after taking ellaOne?

There's no known direct interaction between ellaOne and alcohol. However, if alcohol makes you sick within three hours of taking ellaOne, it may not have been fully absorbed. If that happens, take another tablet as soon as you can.

How to store ellaOne tablets

• Store ellaOne below 25°C, in its original packaging, away from moisture and light.
• Keep it out of sight and reach of children.
• Don't use it after the expiry date printed on the carton.
• Don't throw it away in wastewater or general household waste. Your pharmacist can advise you on how to dispose of it safely.

Alternatives to ellaOne

If ellaOne isn't suitable for you, there are two other options you may want to consider, like:

• Levonorgestrel (Levonelle): Another emergency contraceptive pill that must be taken within three days (72 hours) of unprotected sex. It works in a similar way to ellaOne but has a shorter window of effectiveness.
• Copper IUD (intrauterine device): The copper IUD is the most effective form of emergency contraception available. It can be fitted by a doctor or nurse up to five days after unprotected sex and is over 99% effective. It can also be kept in place as a long-term contraceptive method if you choose to.

Frequently asked questions about ellaOne emergency contraception

Does ellaOne delay your period?

After taking ellaOne, your next period might arrive a few days later than usual. This is a normal effect of the medication and nothing to worry about. If your period is more than seven days late, take a pregnancy test to rule out pregnancy.

How long does ellaOne delay ovulation?

ellaOne works by delaying ovulation, but there's no set timeframe. The delay varies from person to person and depends on where you are in your cycle when you take it. By delaying ovulation, ellaOne reduces the chance of an egg being available to be fertilised.

Can you take ellaOne twice in one cycle?

You can take ellaOne more than once in a cycle if needed, but it's not recommended as a regular form of contraception.

If you're finding yourself needing emergency contraception often, it's a good idea to speak to your GP or pharmacist about finding a longer-term contraceptive method that suits you.

Can ellaOne cause thrush?

Thrush isn't listed as a known side effect of ellaOne. However, the hormonal changes that come with taking the morning after pill can sometimes affect the natural balance of bacteria in the vagina, which may contribute to thrush in some people.

Can ellaOne cause spotting?

Some people do experience light or irregular vaginal bleeding after taking ellaOne. This is listed as an uncommon side effect and is usually nothing to worry about. If bleeding is heavy, prolonged, or you're at all concerned, speak to your GP or pharmacist.

Can you take ellaOne on Mounjaro?

The weight loss injection Mounjaro (tirzepatide) can delay stomach emptying, which may reduce how well your body absorbs oral medicines like ellaOne. This means ellaOne could be less effective if you're taking Mounjaro.

You should speak to your GP or pharmacist about this, as you may want to consider an alternative form.

Sources

• Patient Information Leaflet. MHRA. [Accessed 7th April 2026].
• Can You Take the Morning After Pill if You Have a High BMI? [Accessed 7th April 2026].
• GLP-1 Agonists: Contraception Patient Information. (2025). The Faculty of Sexual and Reproductive Healthcare. [Accessed 7th April 2026].