Differences Between ellaOne and Levonorgestrel

In the UK, there are two types of morning after pill: Levonorgestrel (branded as Levonelle) and ellaOne. Both these morning after pills work in a similar way and are really effective at preventing pregnancy when they’re taken at the right time. However, there are some differences between the two, which might be important for certain women.

Key facts about ellaOne

• Must be taken within five days of unprotected sex
• Contains ulipristal acetate, which affects how progesterone works and stops or delays ovulation
• Shouldn’t be taken when breastfeeding
• Can be used more than once in the same cycle
• Second tablet required if you vomit within three hours of taking ellaOne

Key facts about levonorgestrel/Levonelle

• Must be taken within 72 hours (three days) of unprotected sex
• Contains levonorgestrel, a synthetic version of progesterone, which is thought to stop or delay ovulation
• Safe to take when breastfeeding
• Can be used more than once in the same cycle
• Second tablet required if you vomit within two hours of taking levonorgestrel

Effectiveness and Weight Considerations

It’s generally accepted that ellaOne is more effective at preventing pregnancy than Levonorgestrel. Clinical studies have found that ellaOne is 2.5x more effective than levonelle when taken within 24 hours. However, the most effective form of emergency contraception is the emergency IUD or coil.

Regarding weight, Levonorgestrel is thought to be less effective in women who weigh over 70kg or who have a BMI over 26. The recommendation for women over this weight or BMI may be to take two levonorgestrel tablets, or one ellaOne tablet.

Medication Interactions and Safety

Certain medications interact negatively with the morning after pill, including those for HIV, epilepsy and tuberculosis. For women taking these kinds of medications, ellaOne can’t be prescribed, but levonorgestrel may be given – usually in a higher dose than normal.

Medications that interact with the morning after pill:

• Epilepsy: primidone, phenobarbital, phenytoin, fosphenytoine, carbamazepine, oxcarbazepine and barbiturates
• Tuberculosis: rifampicin, rifabutin
• HIV: ritonavir, efavirenz, nevirapine
• Fungal infections: Griseofulvin
• Various health conditions: St John's wort (Hypericum perforatum)

Breastfeeding and Emergency Contraception

The effects of ellaOne during breastfeeding aren’t known so it’s advised that women who are breastfeeding use levonorgestrel. Levonelle is safe to take while breastfeeding, although small amounts can pass into your breastmilk. It’s not thought to be harmful to your baby.

Suitability for Trans People

The morning after pill can be used by trans people who were assigned female at birth. If you have the potential to become pregnant, have ovaries and a womb you can use ellaOne or levonorgestrel.

Routine Contraception After Use

If you’ve been using routine contraception like the combined pill, there are a few things to bear in mind after taking emergency contraception. After taking levonorgestrel, you should take your next contraceptive pill (or use a new patch or ring) within 12 hours, and then continue using your contraception as normal. If you’re confused about what to do, make sure you speak to a doctor or nurse – and, if in doubt, use condoms.