Esmya

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Esmya

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Esmya

Property Description
Active Ingredient Ulipristal Acetate
Form Oral Tablet
Pharmacological Class Selective Progesterone Receptor Modulator (SPRM)
Common Use Management of Uterine Fibroids (Myoma)
Origin Synthetic Compound

Esmya: A Selective Progesterone Receptor Modulator (SPRM)

Esmya is a prescription-only medicine for oral administration, utilizing the active ingredient Ulipristal Acetate as its sole medicinal compound. This medication is formally classified as a Selective Progesterone Receptor Modulator (SPRM), a specialized group of synthetic compounds within the broader class of hormonal agents. This classification is clinically recognized for providing a targeted method of hormonal control. The SPRM designation means that Ulipristal Acetate is engineered to interact with the progesterone receptor (PR) in a specific, tissue-selective manner, acting as a modulator rather than a simple blocker of the natural hormone. This particular focus on hormonal modulation is a key differentiating factor in its use for adult women of reproductive age.

Composition and Mechanism Principle

As a single active ingredient product, Esmya consists solely of Ulipristal Acetate formulated for oral intake as a tablet, along with necessary solid pharmaceutical excipients. The core mechanism principle involves Ulipristal Acetate rapidly occupying the progesterone receptor, thereby regulating the growth signals that progesterone would normally transmit to cells. This targeted interaction exerts a significant anti-proliferative influence on hormone-dependent tissues. This specific mechanism helps to control and reduce undesirable tissue proliferation and associated symptoms.

General Purpose of the Targeted Therapy

The general purpose of this therapy is to provide effective pharmacological control over specific conditions where tissue growth is dependent on the stimulatory effects of the progesterone pathway. For the target patient group, this oral therapy is designed to mitigate the growth signals, leading to the reduction of tissue size and the alleviation of associated symptoms. The selective nature of the Ulipristal Acetate compound distinguishes it as a modern approach to managing these conditions, providing a non-surgical management option.

Regulatory References

  1. Ulipristal Acetate (MedlinePlus)

What side effects are possible with Esmya?

Possible Side Effects and Safety Information for Esmya

The safety profile for Ulipristal Acetate (Esmya) is officially structured by its classification of adverse reactions and explicit limitations regarding patient health. Effects are grouped into frequency categories and affected physiological systems.

Frequency-Classified Adverse Reactions

The following is a summary of adverse reactions by their official frequency classification, based on regulatory documentation:

Classification Examples of Documented Effects
Very Common (ge 1/10) Amenorrhea (cessation of menses), Endometrial thickening, Headache.
Common (ge 1/100 to < 1/10) Nausea, Hot flush, Musculoskeletal pain, Pelvic pain, Ovarian cyst, Weight increased.
Uncommon (ge 1/1,000 to < 1/100) Anxiety, Dizziness, Constipation, Alopecia, Uterine haemorrhage, Genital discharge.

Serious Adverse Reactions and Safety Constraints

The most significant safety element documented in post-marketing surveillance is the risk of serious hepatic failure (liver failure). This event has been reported, leading to regulatory constraints. The medicine is contraindicated in individuals with a known underlying hepatic disorder, as well as during pregnancy and breastfeeding, and in the presence of certain cancers (uterine, cervical, ovarian, or breast).

Time-Related and Systemic Safety Notes

The effects on the reproductive system are time-related: amenorrhea is typically expected to occur within the first 10 days of treatment. Changes to the endometrium, known as Progesterone Receptor Modulator Associated Endometrial Changes (PAEC), are considered reversible upon treatment cessation. The official labeling notes that Ulipristal Acetate may interfere with the action of hormonal contraceptives.

Overdose and Emergency Response

Overdose and When to Seek Help: Official Regulatory Information

The information in this section outlines the official, regulator-mandated guidance regarding an overdose of Ulipristal Acetate (Esmya).


Documented Overdose Manifestations and Actions

Official regulatory documentation indicates that clinical experience with overdosage is limited. High-dose exposures, such as single doses of up to 100 mg or multiple 20 mg doses administered over several days, were studied in a limited number of individuals. In these documented cases of acute exposure to elevated doses, no serious adverse reactions or events were formally reported in the regulatory labeling.


Emergency Actions Mandated by Regulators

Overdose Component Official Regulatory Statement
Antidote Availability No specific antidote is known for Ulipristal Acetate
Required Medical Action Individuals must seek immediate medical attention
Urgent Contact Contact a doctor or an emergency service immediately
Management Treatment is confined to providing symptomatic and supportive treatment

In the event of a suspected or confirmed overdose, the regulatory documents formally require immediate contact with emergency medical services. Management is restricted to supportive care due to the documented absence of a known specific antidote. The classification of severity is based on the finding that tested acute high-dose exposures resulted in no documented serious adverse reactions.

Therapeutic Uses of Esmya

Main Uses of Esmya

Esmya is primarily used for the management of uterine fibroids, which are non-cancerous growths that develop in or around the uterus. These growths can vary in size and number, often leading to significant physical symptoms that impact daily life.

The medication is typically utilized in two specific clinical scenarios:

  • Pre-operative treatment: To reduce the size of fibroids and manage symptoms before a patient undergoes surgical removal of the growths or the uterus.
  • Intermittent treatment: To manage symptoms on a longer-term basis in women who are not eligible for surgery or who choose to avoid surgical intervention.

Mechanism of Action

The active substance in Esmya is ulipristal acetate. It works by modulating the activity of progesterone, a naturally occurring hormone in the body that stimulates the growth of the uterine lining and the fibroids themselves. By blocking the effects of progesterone, the medication can cause fibroids to shrink and stop or significantly reduce the heavy menstrual bleeding associated with them.

Key Benefits

Reduction of Heavy Bleeding

One of the most immediate benefits experienced is the control of excessive menstrual bleeding. For many, this reduction in blood loss occurs within the first week of treatment, which can help improve energy levels by addressing iron deficiency or anemia caused by heavy periods.

Shrinkage of Fibroids

The treatment acts directly on the fibroid tissue to reduce its volume. Shrinking the growths can alleviate the physical pressure felt in the pelvic area, potentially reducing associated symptoms such as frequent urination or pelvic discomfort.

Surgical Preparation

When used before surgery, the reduction in fibroid size and the improvement in the patient's blood count (due to reduced bleeding) can make surgical procedures less invasive and may decrease the risk of complications during the operation.

Eligibility and Restrictions for Use

Official Population Eligibility for Esmya (Ulipristal Acetate)

The official eligibility criteria for using Esmya are strictly defined by regulatory authorities and focus primarily on adult, premenopausal women. Use of the medicine is contraindicated and must be avoided in several specific populations, particularly due to risks associated with liver function and malignancy.


Populations That Must Not Use Esmya (Contraindications)

Condition/Status Regulatory Status
Pregnancy and Breastfeeding Contraindicated
Underlying Hepatic Disorder Contraindicated
Known Malignancy (Uterine, Cervical, Ovarian, Breast) Contraindicated
Undiagnosed Genital Bleeding Contraindicated
Hypersensitivity to the active substance Contraindicated

Use Restrictions and Age Eligibility

Esmya is officially intended only for adult women (18 years and older) who have not reached menopause. Use in the paediatric population is not established and is considered to have no relevant use. The medicine is also not recommended for patients with severe renal impairment or severe hepatic impairment, except under close monitoring, as established by regulatory documentation.

What should I know about interactions with other medicines?

Esmya (ulipristal acetate) can interact with several types of medications, potentially affecting its efficacy or increasing the plasma concentration of Esmya itself.

Contraindicated or Generally Avoided Combinations

  • Hormonal Contraceptives and Progestogens: Esmya is a Selective Progesterone Receptor Modulator (SPRM). Co-administration with medicinal products containing progestogen, including combined oral contraceptives, progestogen-only pills, or progestogen-releasing intrauterine devices, is not recommended. Progestogens can reduce Esmya's effectiveness through competitive action. After stopping Esmya, hormonal contraceptives should generally not be started for at least 12 days. A non-hormonal barrier method of contraception is recommended during treatment.

  • CYP3A4 Enzyme Inducers: Drugs that induce the CYP3A4 liver enzyme significantly decrease the plasma concentration of Esmya, which may lower its therapeutic effect. Examples include rifampicin, carbamazepine, phenytoin, and the herbal remedy St John's wort (Hypericum perforatum). Concomitant use is not recommended.

  • CYP3A4 Enzyme Inhibitors: Potent and moderate inhibitors of the CYP3A4 enzyme, such as ketoconazole, ritonavir, erythromycin, and grapefruit juice, can increase Esmya's concentration in the blood. This may increase the risk of side effects. Concomitant use is generally not recommended.

  • Glucocorticoids: Esmya can act as an antagonist to the glucocorticoid receptor. Therefore, use in women with severe asthma insufficiently controlled by oral glucocorticoids (like prednisolone) is not recommended, as Esmya may diminish the effect of the glucocorticoid.

  • P-glycoprotein (P-gp) Substrates: Ulipristal acetate may inhibit P-gp in the gut wall, which could potentially increase the absorption and plasma levels of other P-gp substrate drugs, such as digoxin or dabigatran etexilate. The co-administration of Esmya and these substrates should be separated in time by at least 1.5 hours.

Mechanism of Action

Selective Progesterone Receptor Modulation

Ulipristal Acetate is classified as a Selective Progesterone Receptor Modulator (SPRM), meaning it directly engages the Progesterone Receptor (PR) within cells. This interaction allows it to competitively interfere with natural progesterone, acting as a functional antagonist to block progesterone-dependent cellular signaling in specific tissues. This mechanism engages signaling cascades that modulate proliferation and differentiation pathways.


Anti-Proliferative Cascade in Target Tissue

In progesterone-sensitive cells of the uterus, the antagonistic binding to the PR initiates an anti-proliferative cascade. This process actively inhibits cell proliferation and promotes apoptosis (programmed cell death), which modifies molecular steps in tissue maintenance. This targeted activity results in an anti-proliferative and pro-apoptotic cellular effect on progesterone-dependent tissue structures.


Central and Endometrial Pathway Modulation

The drug exerts a dual effect by modulating both the Hypothalamic-Pituitary-Ovarian (HPO) axis and the endometrium. Central action temporarily suppresses the luteinizing hormone (LH) surge. Peripheral action induces a specific, quiescent histological state known as PAEC (Progesterone Receptor Modulator Associated Endometrial Changes) in the uterine lining. This mechanism results in the inactivation of the uterine lining and suppression of ovulation, which are the physiological causes of amenorrhea.

Dosage and Administration Information

Administration Scope: Official Guidelines

The official instructions for Ulipristal Acetate 5 mg establish a precise, non-continuous treatment pattern.

Property Official Administration Instruction
Route of Administration Oral use. Tablets are to be swallowed with water.
Dosing Schedule One fixed dose of 5 mg ulipristal acetate is taken once daily.
Timing in Relation to Meals May be taken with or without food.
Age-Group Rules Use is established only in women 18 years and older.
Missed-Dose Rules If a dose is missed by more than 12 hours, the dose must be omitted, and the usual daily schedule is resumed.
Procedural Condition Treatment must be initiated and supervised by physicians experienced in the diagnosis and treatment of uterine fibroids.

Treatment Cycles and Timing

The use of this medicine is defined by specific timing constraints and an intermittent, cyclic structure, which is critical to the official protocol.

Official Cycle Sequence:

  • First Course Initiation: The first treatment course is to be started during the first week of menstruation.
  • Course Duration: The daily dose is continued for a single, time-bound course of up to 3 months.
  • Interval: A mandatory treatment-free interval must follow the completion of the course.
  • Re-treatment: If re-treatment is required, the new course must begin at the earliest during the first week of the second menstruation following the end of the previous course.

The overall protocol defines the therapy as a fixed daily oral dose delivered through highly structured, intermittent cyclic regimens. This structure outlines the specific procedural requirements, including the necessary timing for course initiation and the required treatment-free breaks.

Recent Clinical Evidence

Research Evidence for Symptomatic Uterine Fibroids (Moderate to Severe Symptoms)

The main body of evidence for Ulipristal Acetate 5 mg comes from major registration studies. These studies are conducted by randomly assigning participants to receive either the medicine, a placebo (inactive pill), or sometimes another active treatment. This approach was applied in studies exploring how symptoms change over time. Subsequent Systematic Reviews and Meta-analyses have also been applied in studies examining patient-reported experiences across the pooled trial data.

Research primarily focused on adult women of reproductive age who were diagnosed with conditions characterized by fluctuating or episodic manifestations, such as excessive menstrual bleeding (menorrhagia) and bulk-related discomfort. Studies monitored outcomes related to functional imbalance and activity level. Researchers monitored specific metrics for bleeding control and cessation, as well as changes in fibroid volume and patient-reported outcomes describing perceived discomfort. The evidence contributes to understanding symptom patterns over the short term.


Study Design and Measured Outcomes

The trials typically involved a short-term, single course of treatment followed by a drug-free period. The research examined how symptoms evolved in the observed populations during these defined time intervals. Trials documented measured patterns related to bleeding control and the proportion of women observed with a period-free state (amenorrhea). Research also describes patterns related to measured change in fibroid volume and outcomes monitoring physiological strain like Hemoglobin levels, which are relevant in evidence describing how symptoms are measured.


Understanding Long-Term and Intermittent Use Evidence

Research has also explored the effects of repeated, intermittent courses of Ulipristal Acetate 5 mg. Research describes the time to recurrence of heavy bleeding after stopping a course of treatment. The data show patterns related to symptom recurrence and reflecting daily functioning or activity level. However, long-term outcomes beyond the defined intermittent treatment protocol are not well characterized by existing major registration trials. Long-term effects are not fully established, and evidence is limited for extended maintenance phases.

Frequently Asked Questions (FAQ)

Common questions about Esmya (FAQ)

Q: Why is Esmya used for fibroids before surgery?

A: Official documents state that ulipristal acetate is indicated for the intermittent treatment of moderate to severe symptoms of uterine fibroids. This includes use as a pre-operative treatment before surgical removal of the fibroids. Its purpose is described as helping manage symptoms like heavy bleeding and achieving a reduction in fibroid volume, according to regulatory indications.

Q: Is Esmya the same type of drug as birth control pills?

A: No, Esmya is not classified as a standard birth control pill. It is a Selective Progesterone Receptor Modulator (SPRM), which means it selectively targets hormone receptors. Official product information notes that hormonal contraceptives containing progestogen may interfere with how Esmya works, meaning they are not recommended for use together.

Q: What happens when I stop taking Esmya?

A: Studies and official information indicate that menstrual cycles generally resume within 4 weeks of completing a treatment course. Any changes to the uterine lining, known as PAEC (Progesterone Receptor Modulator Associated Endometrial Changes), are expected to spontaneously reverse after stopping the medicine.

Q: How quickly does Esmya start affecting fibroid symptoms?

A: Esmya is intended to reduce menstrual blood loss and fibroid size. For the symptom of heavy bleeding, official documents note that the absence of menses (amenorrhea) is often observed within the first 10 days of starting treatment.

Q: Is Esmya a hormone therapy drug?

A: Ulipristal acetate is classified as a Selective Progesterone Receptor Modulator (SPRM), which is a type of sex hormone and modulator of the genital system. This means the drug targets and modulates specific hormone receptors in the body.

Q: Are there specific foods or drinks to avoid while taking Esmya?

A: Official product information notes an interaction concern with foods or drinks that inhibit the CYP3A4 enzyme in the liver. Grapefruit juice is one such example, and its use is described in product information as generally not recommended during treatment.

Q: What is the risk of my fibroids returning after finishing Esmya treatment?

A: Clinical study data have examined the time to recurrence of heavy bleeding symptoms after a treatment course is stopped. Research also suggests that the reduction in fibroid volume achieved during the treatment course persisted for at least 6 months after treatment.

Q: Is it normal to have spotting or breakthrough bleeding while on Esmya?

A: Amenorrhea, or the cessation of menses, is a very common expected effect of Esmya treatment. While cessation of bleeding is expected, the regulatory safety profile lists uterine haemorrhage as an uncommon side effect.

Q: Is Esmya a temporary solution, or can it shrink fibroids permanently?

A: The therapy is administered in defined, intermittent cycles of up to 3 months. While the drug is described as reducing fibroid size, regulatory documents do not contain claims that the shrinkage is permanent.

Q: What are the main differences between Esmya and GnRH agonists?

A: Clinical research has compared the efficacy and tolerability profile of ulipristal acetate with other active treatments, such as the GnRH agonist leuprolide acetate. These studies contribute to the overall understanding of ulipristal acetate’s mechanism and clinical application.

Q: Why is a pregnancy test required before starting Esmya?

A: Official regulatory information states that the medicine is contraindicated, meaning it must not be used, during pregnancy. Additionally, treatment is required to be initiated during the first week of menstruation, making it necessary to exclude pregnancy beforehand.

Q: Are headaches a temporary or long-term side effect of Esmya?

A: Headache is listed in official documents as a very common adverse reaction during treatment. However, regulatory sources do not classify it as being a temporary effect or a long-term effect.

Q: Can Esmya be used if I have allergies to other medications?

A: The medicine is officially contraindicated in cases of known hypersensitivity, or allergy, to the active substance (ulipristal acetate) or any of its inactive ingredients (excipients). Official product information does not list allergies to other, unrelated medications as a contraindication.

Q: Are there any reported interactions between Esmya and herbal supplements?

A: Official product information notes a specific concern regarding drugs that induce the CYP3A4 liver enzyme. The herbal remedy St John’s wort (Hypericum perforatum) is an example of a drug in this category and its use is described as not recommended with Esmya.

Q: How long does the uterine lining change (endometrial thickening) usually last after stopping Esmya?

A: The specific changes to the uterine lining, known as PAEC, reverse spontaneously after the medication is withdrawn. This reversal is noted to occur once menstruation begins following the end of the treatment course.

Q: Why is Esmya sometimes prescribed for up to four cycles?

A: Official regulatory approval is based on clinical trials that investigated and authorized repeated intermittent treatment. The medicine is indicated for up to four intermittent 3-month treatment courses.

Q: Is Esmya a chemotherapy drug?

A: No, Esmya is not classified as a chemotherapy drug or a cytotoxic agent. Ulipristal acetate is formally classified as a Selective Progesterone Receptor Modulator (SPRM), which acts by modulating hormone receptors.

Q: Can I take Esmya if I have kidney problems?

A: Official regulatory information states that no dose adjustment is necessary for individuals with mild or moderate kidney impairment. However, the medicine is generally not recommended in patients who have severe renal impairment unless they are closely monitored.

Q: What should I know about taking Esmya if I'm planning a pregnancy soon?

A: Esmya is contraindicated during pregnancy, and official product information indicates that fertility is likely to return quickly after stopping the treatment. Official product information notes that a reliable, non-hormonal barrier method of contraception is recommended during treatment and for 12 days after the course ends.

Q: Is it common for doctors to monitor fibroid size during Esmya treatment?

A: The treatment must be initiated and supervised by a physician experienced in the diagnosis and treatment of uterine fibroids. Clinical studies have monitored the reduction in fibroid volume as an outcome. This monitoring is typically part of the physician’s supervision for uterine fibroid treatment.

Q: Why is Esmya not available in some countries anymore?

A: The regulatory indication for ulipristal acetate 5mg has been restricted in some regions following a safety review. Official regulatory bodies have released safety updates concerning a rare risk of serious liver injury and liver failure.

Q: Is Esmya used for all sizes or types of uterine fibroids?

A: Clinical trials that supported regulatory approval focused on patients whose largest fibroid measured between 3 cm and 12 cm in diameter. The studies also included women whose uterus size was no larger than that of a 16-week pregnancy.

Q: Is the Esmya treatment protocol different for women over 40?

A: The safety and effectiveness of Esmya were established in adult women aged 18 years and older. Regulatory documents indicate that there are no specific protocol adjustments or different doses based solely on age, excluding post-menopausal women.

Q: Does Esmya have any effect on bone density?

A: Official clinical data indicates that ulipristal acetate does not appear to impact bone turnover. Studies suggest it maintains oestradiol levels within the mid-follicular range, which supports the finding of no adverse impact on bone density.

How should Esmya be stored and disposed of?

Esmya (ulipristal acetate) must be stored and disposed of according to official regulatory specifications to maintain its quality and safety.

Official Storage Requirements

Condition Requirement
Temperature Store below 30°C.
Protection Keep the blisters in the outer carton in order to protect from light.
Stability The shelf life is 3 years when stored under the specified conditions.
Child Safety Keep out of the sight and reach of children.

Disposal Instructions

Regulatory documents state that if the medicine is expired or no longer needed, patients must consult a pharmacist or healthcare professional for guidance on proper disposal. Unused medicine should be disposed of in accordance with local requirements, ensuring it is not improperly discarded in household waste or wastewater.

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

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