ellaOne® Morning After Pill

ellaOne® works by delaying the release of an egg from the ovaries (ovulation) until the sperm in the reproductive tract are no longer capable of fertilising an egg. This is achieved through the mechanism of ulipristal acetate, the active ingredient in ellaOne®, which temporarily blocks progesterone receptors to prevent hormonal changes necessary for the release of a mature egg in the body.

It is important to remember that ellaOne® does not disrupt the implantation or development of an embryo. Therefore, it cannot be used to abort a pregnancy after an egg has already been fertilised.

Take an ellaOne® tablet as soon as possible after unprotected intercourse, swallowing it whole with water. If you forget to take ellaOne®, you can still do so for a maximum of 5 days (120 hours). ellaOne® can be taken at any time during the menstrual cycle.

Individuals who vomit or experience diarrhoea within 3 hours of taking an ellaOne® tablet are advised to take another ellaOne® tablet after consulting a pharmacist or GP, as the initial dose may not have been absorbed properly, which can compromise its efficacy.

ellaOne® is 98% effective at preventing unplanned pregnancy, provided it is taken correctly according to the instructions in the patient information leaflet. ellaOne® is most effective when taken as soon as possible and loses its efficacy with time, as it must be taken before an egg is released from the ovaries.

The efficacy of ellaOne® can also depend on certain physiological factors, including:

• Ovulation timing - ellaOne® is formulated to delay ovulation, as opposed to aborting a pregnancy after an egg has been fertilised. Therefore, ellaOne® cannot prevent pregnancy if it is taken after ovulation has already occurred.
• Hormone fluctuations - ellaOne® works by blocking progesterone receptors to delay ovulation. When the body’s progesterone levels are high, the active ingredient in ellaOne® cannot block progesterone receptors as effectively. This reduces the efficacy with which the treatment can delay ovulation to prevent an unplanned pregnancy.

It is important to note that ellaOne® is an emergency contraception treatment which is formulated to be used on one-off occasions, as opposed to being used daily. Individuals seeking daily, ongoing contraception are recommended to consider taking daily contraceptive pills and/or using a reliable form of barrier contraception, such as condoms.

ellaOne® should not be used by individuals who are:

• Allergic to ulipristal acetate or any additional ingredients in the medication
• Already pregnant, as ellaOne® cannot terminate an existing pregnancy

In some cases, ellaOne® can be taken after consulting a pharmacist or doctor to determine suitability. This applies to individuals who:

• Are severely asthmatic, as ellaOne® can affect the body’s hormonal balance, which may subsequently affect airway responsiveness. Fluctuations in hormone levels might lead to increased airway inflammation or bronchial hyperreactivity in some individuals, potentially exacerbating asthma symptoms.
• Have severe liver disease, as ellaOne® can affect the liver's ability to adequately metabolise the treatment, causing fluctuations in the body’s hormone levels.
• Experience common symptoms of pregnancy, such as a late period, nausea or breast heaviness, as this can imply the individual is already pregnant.
• Are breastfeeding, as ellaOne® may affect a baby during the first week of the mother taking this treatment. Individuals who are breastfeeding are recommended to speak with their GP for further advice, as we would not recommend taking ellaOne® while breastfeeding.

For detailed information regarding the correct use of ellaOne®, please refer to the patient information leaflet for ellaOne®.

ellaOne® is called the 'morning after pill' as it can prevent an unplanned pregnancy anywhere from the morning after engaging in unprotected intercourse up to five days later.

While ellaOne® is called the morning-after pill, it should actually be taken as soon as possible, as delaying the intake of ellaOne® increases the probability of ovulation, at which point ellaOne® cannot prevent pregnancy.

If you have unprotected sex after taking ellaOne®, it will not prevent pregnancy because its primary function is to delay ovulation. Any sperm from subsequent unprotected sex can still fertilise an egg when it is eventually released.

Individuals taking other medication are recommended to consult a pharmacist or doctor before taking ellaOne®, due to the effects of certain treatments on the efficacy of ellaOne®. This includes:

• Epilepsy medication, such as Phenytoin, Carbamazepine, Primidone or Barbiturates, which can accelerate how quickly the liver breaks down ellaOne® in the body
• HIV medication, such as Ritonavir or Efavirenz, which speed up the breakdown of ellaOne® in the body
• Tuberculosis medications, such as Rifampicin and Rifabutin, which can also speed up the breakdown of ellaOne® in the body
• Acid reflux medication, such as Omeprazole, which can affect the absorption of ellaOne® in the body, reducing its efficacy
• St John’s Wort, which can affect the rate at which ellaOne® is metabolised in the body, reducing how long the treatment remains effective

The two primary alternatives to ellaOne® are:

• Levonorgestrel - a hormonal emergency contraceptive containing the active ingredient ‘levonorgestrel,’ which inhibits the release of a hormone known as luteinising hormone (LH) that is necessary for the release of a mature egg from the ovaries.
• Levonelle - a branded version of Levonorgestrel which also contains the active ingredient ‘levonorgestrel’. Levonorgestrel and Levonelle are medically identical, which means they contain the same strength of the same active ingredient and are therefore equally effective at preventing unplanned pregnancy. The only difference between these treatments is the brand - Levonelle is more expensive, as it is a branded treatment, while Levonorgestrel is cheaper, as it is a generic treatment.

The main difference between ellaOne® and Levonorgestrel/Levonelle is the duration of the effects of each treatment:

• ellaOne® is effective for up to 5 days (120 hours) after unprotected sex
• Levonorgestrel and Levonelle are effective for up to 3 days (72 hours) after unprotected sex

The discrepancy in the duration of effectiveness is due to differences in how each type of emergency contraceptive interacts with the hormonal processes that regulate ovulation:

• ellaOne® contains the active ingredient ulipristal acetate, a selective progesterone receptor modulator (SPRM). Ulipristal acetate works by blocking progesterone receptors in the body, delaying ovulation and preventing the egg from being available for fertilisation while sperm are still viable. Because ellaOne® more effectively blocks progesterone, even when ovulation is already starting, it extends the window in which it can prevent pregnancy.
• Levonorgestrel and Levonelle contain the active ingredient levonorgestrel, a synthetic hormone similar to natural progesterone. Levonorgestrel works by mimicking progesterone, signalling to the body that ovulation has already occurred, thereby preventing the release of an egg. However, Levonelle becomes less effective once ovulation has begun and cannot delay ovulation if it is too close to occurring.