EllaOne

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EllaOne

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of EllaOne

What is EllaOne?

EllaOne is an emergency contraceptive intended for use after unprotected sexual intercourse or when a regular contraceptive method has failed. It belongs to a class of medications known as selective progesterone receptor modulators.

Primary Function

The medication works by modifying the activity of progesterone, a hormone naturally produced in the body that plays a critical role in the timing of ovulation. By interacting with these hormone receptors, the treatment aims to delay the release of an egg from the ovary.

Mechanism of Action

Pregnancy occurs when an egg is fertilized by sperm and successfully implants in the uterus. For pregnancy to begin, ovulation must take place. EllaOne acts by postponing ovulation, even if the biological process leading up to the release of an egg has already started.

Because its primary function is to prevent or delay ovulation, the medication is not effective if ovulation has already occurred. It is designed specifically as a backup method for emergency situations and is not intended for use as a regular form of long-term contraception.

Regulatory References

  1. EMA

What side effects are possible with EllaOne?

Officially Documented Adverse Reactions

The safety profile of Ulipristal Acetate is established through regulatory classification of adverse reactions based on frequency, as defined in official prescribing information. The most commonly reported side effect is headache, which is classified as Very Common (ge 1 in 10 patients).

Other frequently reported adverse reactions, categorized as Common (ge 1 in 100 to < 1 in 10 patients), often involve the Gastrointestinal and Reproductive System Disorders. These common effects include nausea, abdominal pain, dysmenorrhoea (painful menstruation), pelvic pain, fatigue, and dizziness.

Safety Constraints and Considerations

The regulatory label for this medicine highlights specific constraints and critical safety considerations:

  • Contraindications: Use is strictly contraindicated in the case of known or suspected pregnancy. The medicine is also not recommended for individuals with severe hepatic impairment due to a lack of specific studies in this patient population.
  • Serious Outcome: As with any emergency contraceptive, if treatment failure occurs and pregnancy results, the possibility of a serious, life-threatening ectopic pregnancy must be considered.
  • Time-Related Pattern: A documented pattern is the potential for a disruption to the menstrual cycle, with the next period sometimes occurring earlier or later than expected. A delay of more than seven days warrants a safety follow-up.
  • Interactions: The safety of the medicine may be reduced when administered alongside certain CYP3A4 enzyme inducers (such as specific anti-epileptic drugs or St. John's wort), which can compromise its effectiveness.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory prescribing information documents that experience with Ulipristal Acetate overdose is limited. Clinical trial data reviewed by government health authorities reported that single doses up to four times the therapeutic dose (120 mg) were administered to subjects without any resultant adverse reactions. Furthermore, studies involving even higher single doses, up to 200 mg, reported no severe or serious adverse reactions. The documented overdose profile is therefore characterized by the absence of specific, severe clinical manifestations observed in these high-exposure settings.

Due to the general risks associated with any drug overdose, authorities mandate that immediate medical attention must be sought in all suspected cases. Individuals should contact the Poison Control Helpline for guidance. Urgent medical services must be called immediately if critical clinical signs are present, including collapse, the onset of a seizure, severe trouble breathing, or if the individual cannot be awakened.

The official regulatory documents do not specify a known antidote for Ulipristal Acetate overdose, nor do they detail specific procedural interventions such as gastric lavage. Management is generally described as symptomatic and supportive care. No specific population-based considerations regarding overdose severity for groups such as those with renal or hepatic impairment are noted in the official labeling.

Therapeutic Uses of EllaOne

What EllaOne Treats: Main Uses and Benefits

EllaOne (Ulipristal Acetate) is applied in situations involving certain distressing symptoms following unexpected events, relevant in areas where short-term symptom management is appropriate. The medicine is generally used in areas where short-term symptom management is appropriate, applied in situations involving certain distressing symptoms. Its indication is relevant for use following the event.

This medication is applied in addressing the potential for conception that arises after an instance of unprotected sexual intercourse (UPSI) or following a failure of a primary contraceptive method. The primary benefit of its use is providing support that helps ease the overall burden of risk and is commonly used after the event, offering critical, time-sensitive support to manage reproductive risk. The medication is applicable in clinical scenarios such as condom breakage or slippage and the omission of multiple scheduled doses of routine birth control pills.

“This supportive relief may assist with maintaining functional stability when symptoms are more notice-able, contributing to easing the overall symptom load during episodes of heightened symptoms.”


Quick Fact: Relief for Acute Contraceptive Risk The product is commonly used when symptoms cluster into patterns requiring supportive management after a potential exposure, providing symptomatic relief that helps patients cope more steadily with symptom fluctuations.

Regulatory References

  1. European Medicines Agency (EMA) overview of ellaOne

Eligibility and Restrictions for Use

Who Can and Cannot Use EllaOne?

EllaOne (Ulipristal Acetate) is approved for use by women of childbearing age, including post-menarcheal adolescents, following unprotected sexual intercourse or contraceptive failure within five days (120 hours). Eligibility is strictly defined by government regulatory documents based on physiological status, pre-existing conditions, and potential for interaction.

Population Status Regulatory Classification Details
Pregnancy Contraindicated Must not be used if pregnancy is known or suspected.
Hypersensitivity Contraindicated Prohibited for patients with hypersensitivity to ulipristal acetate or any excipients.
Severe Hepatic Impairment Not Recommended Use is not recommended for patients with severe liver disease due to insufficient data.
Breastfeeding Restricted Use Not recommended for one week after intake, as the active substance is excreted in milk.

The medicine is not intended for use in prepubertal children or postmenopausal women. Additionally, use is not recommended for women with specific conditions, such as severe asthma treated with oral glucocorticoids, or for those who have used strong CYP3A4-inducing medicinal products in the previous four weeks. Patients with rare hereditary metabolic problems like Lapp lactase deficiency are also ineligible due to the presence of lactose. No dose adjustment is specified for patients with renal impairment.

What should I know about interactions with other medicines?

The regulatory profile for Ulipristal Acetate is structured by specific pharmacokinetic and pharmacodynamic constraints. The primary pharmacokinetic interaction involves the CYP3A4 metabolic pathway. Products classified as strong or moderate CYP3A4 inducers are formally restricted from co-administration. These inducers, which include prescription medicines like Rifampicin, Carbamazepine, and Phenytoin, as well as the herbal product St. John's Wort, dramatically reduce the plasma concentrations (AUC and Cmax) of Ulipristal Acetate by 90% or more, which may decrease its effectiveness. Conversely, CYP3A4 inhibitors (e.g., Ketoconazole) increase exposure, but this effect is generally considered unlikely to cause clinical consequences.

The essential pharmacodynamic conflict exists with progestin-containing hormonal contraceptives and levonorgestrel emergency contraceptives. These combinations are restricted because they may impair the ability of Ulipristal Acetate to delay ovulation through antagonistic action at the progesterone receptor. To manage this conflict, official labeling requires that hormonal contraceptives be initiated or resumed no sooner than 5 days after the intake of Ulipristal Acetate. Additionally, products that increase gastric pH may reduce Ulipristal Acetate plasma concentrations.

Mechanism of Action

EllaOne (ulipristal acetate) acts by interacting with defined hormonal pathways, specifically targeting the progesterone receptor (PR). The molecule functions as a selective progesterone receptor modulator (SPRM). This molecular action fundamentally alters the cellular response to natural progesterone in target tissues, initiating the drug's primary mechanistic cascade. Within the neuroendocrine system, the drug's action on the PR leads to the suppression of the Luteinizing Hormone (LH) surge—the hormonal peak required to trigger follicular rupture. This interference with the neuroendocrine pathway is the primary mechanism by which the release of an egg (ovulation) is prevented or delayed. A secondary mechanistic domain involves the reproductive tract. The drug's influence extends to the endometrium (uterine lining), engaging mechanisms that result in changes to its cellular morphology and characteristics. This action constitutes a secondary mechanistic domain that modulates the uterine environment.

Dosage and Administration Information

How to Use EllaOne

This section outlines the administration guidelines for EllaOne (ulipristal acetate), focusing strictly on the procedural instructions.


Administration Scope

Category Instruction
Route and Form Administered orally as a single 30 mg tablet.
Dosing Regimen A single dose of one 30 mg tablet of ulipristal acetate.
Timing in Relation to Meals May be taken with or without food.
Missed-Dose Protocol If vomiting occurs within 3 hours of intake, a repeat dose is required.

Procedural Constraints

The medicine is designed as a time-critical intervention, which determines its frequency and timing rules. The single dose must be administered as soon as possible, and no later than 120 hours (5 days) following unprotected sexual intercourse or known contraceptive failure. The administration can occur at any time during the menstrual cycle. Repeated administration within the same menstrual cycle is not recommended.

Population-specific constraints include that the medicine may be used in women of childbearing age, including adolescents, and no dose adjustment is specified for renal impairment. However, use is not recommended in women with severe hepatic impairment.


Connection to the Overall Use Protocol

These instructions establish a structured protocol defining the medicine's use as a non-routine, single oral dose intervention. The framework prioritizes the time-critical administration within a strict 120-hour window, while offering flexibility regarding food intake and cycle timing. This framework limits this product to occasional use, advising that a reliable barrier method be adopted for subsequent acts of intercourse until the next menstrual period.

Recent Clinical Evidence

Recent Clinical Evidence: Ulipristal Acetate (EllaOne)

Ulipristal acetate is an emergency contraceptive approved for use up to 120 hours (five days) after unprotected sexual intercourse. Clinical research, including randomized controlled trials, focuses on its efficacy, the optimal time window for use, and its safety profile compared to other emergency contraceptive methods.

Efficacy and Comparative Studies

Clinical trials have investigated the pregnancy rate following use of ulipristal acetate (UPA) compared to levonorgestrel (LNG). In the primary comparative studies, UPA was found to prevent a greater percentage of expected pregnancies than LNG when taken within 72 hours of unprotected intercourse. UPA is consistently effective throughout the entire 120-hour window, while the efficacy of LNG may decrease more significantly after 72 hours.

Post-marketing surveillance and systematic reviews indicate that UPA's mechanism—the inhibition or delay of ovulation—may allow it to be effective even when administered after the luteinizing hormone (LH) surge has already begun, a point at which LNG is less likely to be effective. Studies have also suggested that UPA's efficacy may be less impacted by increased body weight or Body Mass Index (BMI) compared to LNG, though data in this area remain limited.

Safety and Tolerability

UPA has generally been observed to be well-tolerated. The most commonly reported side effects in clinical trials and post-marketing experience include headache, nausea, abdominal pain, and menstrual irregularities such as a delay or early onset of the subsequent menstrual period. No new or unexpected serious safety concerns have emerged from post-marketing experience with UPA.

Frequently Asked Questions (FAQ)

Common questions about EllaOne (FAQ)


Q: How is EllaOne different from the other common morning-after pill (levonorgestrel)?

Studies have examined EllaOne's effect compared to levonorgestrel. Regulatory evidence indicates it prevents a greater percentage of expected pregnancies than levonorgestrel when taken within 72 hours. The drug's indication for use extends up to 120 hours (five days).


Q: Do birth control pills affect how well EllaOne works?

Official documents state that taking combined hormonal contraceptives or progestogen-only contraception may interfere with the medicine's action. This interference could potentially reduce the medicine's intended effect. For subsequent acts of intercourse until the next menstrual period, the official protocol outlines the use of a reliable barrier method.


Q: What should a person do if they are late taking their regular birth control after using EllaOne?

The medicine is not intended to provide continuous protection. Official guidelines state that if hormonal contraception is resumed immediately after taking EllaOne, the use of a reliable barrier method is outlined in the instructions for all subsequent acts of intercourse until the start of the next menstrual period.


Q: What information is available about abdominal pain as a side effect?

Abdominal pain is listed as a common side effect in the official product information. Regulatory warnings highlight that if a pregnancy test is positive after treatment, the possibility of a serious, life-threatening ectopic pregnancy must be considered.


Q: Are there specific weight limits mentioned in the official documents for using EllaOne?

Official documents do not establish specific weight limits for the medicine's use. Clinical studies have suggested that the medicine's effectiveness may be less impacted by increased body weight compared to levonorgestrel.


Q: Can EllaOne be purchased if someone is taking epilepsy medication?

Taking the medicine is not recommended alongside certain anti-epileptic drugs, such as carbamazepine, phenytoin, or phenobarbital. This is because these drugs are known to significantly reduce the active substance's concentrations in the body, which may result in decreased effectiveness.


Q: Does taking EllaOne guarantee that I won't get pregnant?

Official documents indicate that the medicine does not prevent pregnancy in every case. Emergency contraception with EllaOne reduces the number of unintended pregnancies.


Q: Can taking EllaOne change the timing of my next period?

Yes, the medicine can affect the timing of the next period. It may occur either earlier or later than expected. Delays of more than seven days have been documented in clinical studies.


Q: Are there any non-prescription medicines or supplements that interact with EllaOne?

Regulatory information specifically states that the herbal product St John's Wort may interact with the medicine. It is not recommended due to potential interference that could decrease its intended effectiveness.


Q: Is EllaOne effective if ovulation has already occurred?

Official regulatory documents state that the medicine works mainly by preventing or delaying ovulation (the release of an egg). If ovulation has already occurred, the medicine is no longer effective.


Q: Is EllaOne available for purchase without a prescription?

The medicine is generally available for purchase without a prescription from a pharmacist in the European Union and the United Kingdom. This regulatory status may differ based on the specific country or region.


Q: How long does EllaOne stay in the system or remain effective?

The medicine's protective action is limited to the single instance of intercourse for which it was taken. The drug is not intended to provide continuous protection against subsequent unprotected sex in the same menstrual cycle.


Q: Can EllaOne be used by people who are under 18 years old?

The medicine is approved for use in women of childbearing age, which includes adolescents who have started menstruating (post-menarcheal). Some regulatory bodies have stated there is no age restriction for its use.


Q: Are there medical conditions that would prevent someone from using EllaOne?

Use is strictly contraindicated (prohibited) in the case of known or suspected pregnancy or known hypersensitivity. Use is also generally not recommended for individuals with severe hepatic (liver) impairment or severe asthma treated with oral glucocorticoids.


Q: Do antibiotics affect the way EllaOne works?

Regulatory documents state that only certain antibiotics, specifically rifampicin and rifabutin, are known to reduce the medicine's concentrations in the body and are not recommended. Other common antibiotics are not listed as having this specific interaction in the official product information.


Q: Can a person take EllaOne if they are breastfeeding?

Use is not recommended while breastfeeding. Regulatory information describes that for one week (7 days) after taking the medicine, breast milk should be expressed and discarded, as the active substance is excreted into the milk.


Q: Does taking EllaOne impact future fertility?

The medicine only affects the menstrual cycle in which it is taken. Following its use, a rapid return to fertility is expected, and the subsequent menstrual cycle should return to its normal rhythm.


Q: What should a person do if a regular period is delayed after taking EllaOne?

Official guidance indicates that if the next menstrual period is more than seven days late, is unusually light or heavy, or if symptoms of pregnancy are experienced, a pregnancy test may be warranted to exclude pregnancy.


Q: What information is provided regarding drug interactions with HIV medications?

Regulatory documents list specific HIV medications, such as efavirenz, nevirapine, and long-term use of ritonavir, as substances that can reduce the medicine's concentrations and are not recommended.


Q: Does alcohol consumption interfere with the function of EllaOne?

There is no known pharmacological interaction between the medicine and alcohol. Regulatory information does not state that alcohol directly reduces the effectiveness of the tablet itself.


Q: Are there studies comparing the tolerability of EllaOne versus levonorgestrel?

Clinical trial data indicate that the medicine is generally well-tolerated. Common side effects reported include headache, nausea, and abdominal pain.


Q: Is EllaOne approved for use as regular birth control?

The medicine is approved only as an emergency contraceptive and is not intended for use as a regular, routine form of birth control. It is limited to a single oral dose intervention.


Q: What is the difference between EllaOne and ella (the prescription-only version in the US)?

The two names refer to the same active ingredient, ulipristal acetate. The name used depends on the region; for example, 'ella' is the brand name used in the United States, and 'ellaOne' is the common brand name in Europe.


Q: What does the clinical research say about the effectiveness rate?

Clinical studies demonstrated that 2.1% of women who took the medicine became pregnant, compared to an expected rate of 5.5% if they had not taken any contraceptive.


Q: Are there any long-term effects reported from taking EllaOne?

The effects of the medicine are primarily limited to the menstrual cycle in which it is taken. The subsequent period is expected to return to its regular rhythm.


Q: Are there any genetic factors that influence how EllaOne works in a person?

The active substance is metabolized by the CYP3A4 enzyme system in the body. The function of this enzyme can be influenced by certain co-administered medicines, but the regulatory documents do not provide a consumer-facing statement on general genetic factors.


Q: Are there warnings about taking EllaOne with anti-fungal medications?

Regulatory information notes that potent CYP3A4 inhibitors, which include some anti-fungal medications like ketoconazole, may increase exposure to the active substance. However, the clinical relevance of this increase is not currently known.


Q: Does the manufacturer's information include details on severe side effects?

Official documents detail side effects categorized by frequency (e.g., common, uncommon, rare) and note the rare possibility of a severe allergic reaction. Warnings also highlight the need to consider ectopic pregnancy if treatment fails.


Q: What are the risk factors that could lower the effectiveness of EllaOne?

Risk factors that may lower effectiveness include taking the medicine more than 120 hours after unprotected sex. Effectiveness may also be reduced by taking it with specific CYP3A4 enzyme-inducing medicines or herbal products.


Q: What has been reported regarding mood changes or headaches after taking EllaOne?

Headache is reported as a very common side effect. Mood changes are also reported but are listed in the less common frequency category.

How should EllaOne be stored and disposed of?

The official regulatory documentation for EllaOne (ulipristal acetate 30 mg) provides specific instructions for storage, protection, and disposal.

Storage and Handling Requirements

  • Temperature and Environment: Store the medicine below 25 C.
  • Light and Moisture Protection: Keep the tablet in the original packaging and the outer carton to protect it from light and moisture.
  • Child Safety: The product must be stored out of the sight and reach of children.

Disposal Instructions

  • Waste Protocol: Do not dispose of unused or expired medicine in household waste or via wastewater.
  • Environmental Protection: To help protect the environment, return any medicine no longer needed to your pharmacist for proper disposal.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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