Femilar

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Femilar

Method of action: Endocrine Therapy

Treatment option:

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 Femilar

Quick Facts: Femilar

Property Description
Active Ingredients Cyproterone Acetate, Estradiol Valerate
Form Oral Tablet (Pill)
Pharmacological Class Combined Hormonal Contraceptive; Antiandrogen/Estrogen Combination
General Purpose Prevention of Pregnancy (Contraception)
Origin Synthetic Hormonal Compound

What Type of Medicine is Femilar?

Femilar is a prescription-only, synthetic Combined Hormonal Contraceptive Preparation classified within the pharmacological group of Sex Hormones and Modulators of the Genital System. This medication is definitively identified as a Combination Product, delivered through the simplest route of administration as an Oral Tablet or pill. Its compound nature ensures the simultaneous delivery of both estrogenic and antiandrogenic activity. The classification of Cyproterone as a steroidal antiandrogen and progestogen highlights its unique position within the contraceptive class.

The Composition of Femilar: Cyproterone and Estradiol Valerate

The preparation's function is determined by its active ingredients: Cyproterone Acetate and Estradiol Valerate. Estradiol Valerate serves as the estrogen component, acting as a pro-drug ester designed to release natural estradiol into the body. The Cyproterone Acetate component functions as the progestogen and, notably, as an antiandrogen. Cyproterone's mechanism is to selectively antagonize androgen receptors, confirming that this active ingredient offers a distinct systemic effect against male hormones.

General Purpose and Dual Action of the Combination

The overarching, highly reliable general purpose of Femilar is the prevention of conception, which it achieves primarily through ovulation suppression. The unique composition of the hormone combination works to interrupt the reproductive cycle while concurrently managing androgenic activity. This dual function provides the general benefit of effective contraception alongside a systemic effect that manages physiological responses related to excess male hormones, achieved through the direct blocking of androgen receptors by the Cyproterone component. The inclusion of cyproterone acetate is specifically utilized to leverage this anti-androgen property within the combined contraceptive framework.

What side effects are possible with Femilar?

Official Safety Profile and Documented Adverse Reactions

The safety profile for Femilar, a combined hormonal contraceptive containing Cyproterone Acetate and Estradiol Valerate, is structured around frequency classifications and specific serious risks defined in official regulatory documents.

Adverse reactions are classified into physiological systems, including Vascular Disorders, Hepatobiliary Disorders, Reproductive System and Breast Disorders, and Psychiatric Disorders.

Frequency Classification of Documented Effects

The majority of side effects are classified as Common (ge 1/100 to < 1/10) in regulatory labels. These typically include: Headache, Nausea, Breast pain/tenderness, Depressed mood, Weight fluctuations, and Irregular menstruation. Uncommon (ge 1/1,000 to < 1/100) effects include decreased libido and rash. Rare (ge 1/10,000 to < 1/1,000) effects include Hypersensitivity reactions.


Serious Adverse Reactions and Restrictions

Official regulatory sources highlight the risk of Serious Adverse Reactions. These include Venous Thromboembolism (VTE) and Arterial Thromboembolism (ATE). Furthermore, risks such as Benign or Malignant Liver Tumours and the association with Meningioma (linked to cumulative Cyproterone exposure) are documented safety considerations.

Usage is officially restricted and contraindicated in individuals with pre-existing conditions that increase risk, such as a history of thrombotic events, severe hepatic impairment, or a history of Meningioma.

Time- and Population-Specific Safety Notes

The risk of VTE is documented as highest during the first year of initial use. Bleeding irregularities are frequently reported during the initial three to six months of treatment. Regulatory labels also specify increased risk for certain populations, particularly women aged 35 years or older who smoke, due to a significantly increased risk of serious cardiovascular events.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with products containing estrogen, the likely active component in Femilar, is generally not expected to produce acutely serious symptoms, though all instances of suspected overdose require prompt medical evaluation. Instances of accidental or intentional ingestion of large doses have not been associated with severe immediate effects.

Documented Overdose Manifestations
Nausea and Vomiting
Breast tenderness or pain
Drowsiness and fatigue
Headache
Fluid retention or abdominal pain
Excessive vaginal bleeding (typically 2 to 7 days after the overdose event)

When to Seek Immediate Medical Help

The most important step in a suspected overdose is to seek emergency medical help right away, regardless of whether any symptoms are currently visible. Do not attempt to induce vomiting unless specifically instructed to do so by a healthcare professional or a poison control center, as immediate professional guidance is necessary to assess the exposure and determine the required course of action, which may include supportive care or monitoring. Authorities recommend having the product name and strength, the person's age, and the amount swallowed readily available when seeking assistance.

Therapeutic Uses of Femilar

Femilar is generally used in therapeutic contexts requiring both effective pregnancy prevention and the symptomatic management of symptoms related to systemic imbalance, such as hyperandrogenism, in women of reproductive age. The antiandrogenic component has a therapeutic role in managing androgen-dependent symptoms when contraception is also relevant.


Dual Benefit: Effective Contraception and Cycle Regulation

This medication is commonly used to provide effective pregnancy prevention as part of its therapeutic effect. Concurrently, it is relevant in clinical situations where underlying hormonal irregularities cause disturbances in the menstrual cycle. The use of Femilar may assist with establishing a more regulated menstrual cycle pattern, which contributes to improved stability and helps ease the impact of unpredictable cycles on daily life.

The primary therapeutic contexts involve addressing symptoms such as preventing pregnancy, managing moderate to severe acne, and providing symptomatic support for hirsutism (excessive hair growth).

“Femilar is commonly used when patients require both hormonal contraception and assistance with managing visible androgen-related symptoms.”


Managing Androgen-Related Skin and Hair Symptoms

Femilar is relevant for the symptomatic treatment of physical manifestations associated with systemic hormonal imbalance, including moderate to severe acne vulgaris and excessive skin oiliness (seborrhea). Furthermore, it supports the management of hirsutism (unwanted terminal hair growth) and androgenetic alopecia. This treatment may assist with easing the symptom load of persistent skin issues and supports the gradual, long-term management of challenging hair symptoms.

Quick Fact: Symptomatic Support
Primary Focus Symptoms of systemic imbalance (hyperandrogenism)
Key Benefit Contributes to easing the symptom load in symptomatic areas.
Usage Context Relevant in situations involving noticeable symptoms

Regulatory References

  1. Assessment report cyproterone acetate/ethinylestradiol

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Femilar — Official Regulatory Information

This medication is a prescription-only combined hormonal product intended for females of reproductive age who require both contraception and management of specific androgen-related symptoms.

Contraindicated Populations (Must Not Use)

Eligibility Scope Statement based on Regulatory Documents
Cardiovascular/Thrombotic Risk Current or history of venous or arterial thromboembolism (VTE/ATE) or known thrombophilias. Use is also prohibited with migraine with focal neurological symptoms or uncontrolled severe hypertension [Source: Official Labeling].
Hepatic Function Patients with severe hepatic disease or a history of liver tumors must not use this medicine [Source: Official Labeling].
Malignancy Known or suspected sex-hormone-dependent malignancies (e.g., breast cancer) are an absolute contraindication [Source: Official Labeling].

Age and Status Restrictions

Eligibility Scope Statement based on Regulatory Documents
Age-Related Contraindicated before menarche. Use is not indicated in post-menopausal women. Prohibited for women aged 35 years and older who smoke [Source: Official Labeling].
Reproductive Status Pregnancy is an absolute contraindication and must be excluded prior to use. Use is not recommended while breastfeeding [Source: Official Labeling].
Conditional Use Patients with Diabetes Mellitus (especially with vascular complications) require monitoring. Use must be discontinued four weeks prior to major surgery involving prolonged immobilization [Source: Official Labeling].

What should I know about interactions with other medicines?

Interactions with other medicines and products

Interactions with other medicinal products are chiefly pharmacokinetic, involving alterations to the body's processing of the hormonal components, which may reduce the medicine's efficacy or increase the risk of adverse effects. These interaction patterns are organized into classifications reflecting their effect on systemic exposure.

Pharmacokinetic Exposure Changes

Co-administration with enzyme-inducing substances (primarily CYP3A4 inducers) may increase the clearance of the estrogen component. This is documented for medicines such as Rifampin, Phenytoin, Phenobarbital, and Carbamazepine, and may result in reduced plasma concentrations. Conversely, the co-administration of CYP3A4 inhibitors (e.g., Ketoconazole, Ritonavir) can decrease the hormonal component's clearance, which may increase systemic exposure. Certain antibiotics (e.g., Amoxicillin, Ampicillin) and the retinoid Acitretin are also noted to decrease the efficacy of the Cyproterone Acetate component.

Drug-Substance and Regulatory Restrictions

Interaction with herbal products includes St. John's Wort, which may reduce the hormonal plasma concentrations via enzyme induction. Consumption of Grapefruit juice may increase estrogen levels through enzyme inhibition. The European Medicines Agency (EMA) and national regulators impose a precautionary restriction: the product is contraindicated in people who have or have had a meningioma, which applies to all Cyproterone Acetate-containing products regardless of dose. Additionally, systemic exposure to the Cyproterone component may be heightened in patients with liver disease due to officially documented reduced clearance.

Mechanism of Action

The mechanism of action involves coordinated pharmacodynamic effects mediated by an estrogen component (estradiol valerate) and a progestin/antiandrogen component (cyproterone acetate).

Hypothalamic-Pituitary Axis Modulation

Both agents modulate hormonal signaling pathways through feedback inhibition. They suppress the release of gonadotropins (Follicle-Stimulating Hormone and Luteinizing Hormone) from the pituitary gland. This leads to the suppression of the hypothalamic-pituitary-ovarian axis, which consequently prevents the preovulatory surge of Luteinizing Hormone and subsequent follicular rupture.


Progestational Receptor Activity

Cyproterone acetate acts as an agonist within domains involving progesterone receptor-mediated signaling. This activity initiates structural and secretory changes within the endometrium. It also modulates the physicochemical properties of cervical secretions, increasing viscosity and reducing permeability.


Androgen Receptor Blockade

Cyproterone acetate engages a distinct mechanism by acting as a competitive antagonist at the androgen receptor (AR). This action directly blocks the binding of endogenous androgens (such as testosterone) to the receptor in peripheral target tissues, thereby modulating the downstream effects of androgens.

Dosage and Administration Information

Femilar is administered through the oral route and follows a cyclic sequential regimen structured for daily hormone delivery. The administration protocol generally requires taking one tablet daily to maintain consistent hormonal levels. To ensure reliable usage, the tablet must be swallowed whole with liquid and taken at the same time every day throughout the prescribed cycle. The regimen typically involves 21 days of active hormone tablets followed by a 7-day tablet-free or low-hormone phase, after which a new cycle is initiated.

Guidance for the duration of use when Femilar is utilized for androgen-dependent symptoms indicates that treatment is generally recommended to be discontinued 3 to 4 cycles after the symptoms have fully resolved, and it should not be continued solely for contraception once the non-contraceptive treatment goal is met.

In the event of a missed dose, if a daily tablet is delayed, taking it as soon as the delay is noticed is required; however, the contraceptive protection is maintained only if the delay is within 12 hours of the usual scheduled time. Furthermore, the medicine is not indicated for use in children before menarche or in women who have reached menopause. This administration framework governs the drug's standardized clinical use.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Femilar

Evidence for Use in Pregnancy Prevention (Contraception)

Research exploring data patterns related to the long-term use of this pharmacological class includes large-scale Epidemiological Observational Studies and comprehensive Systematic Reviews. Studies monitored whether outcomes related to physical discomfort (such as the occurrence rate of pregnancy) changed within the observed populations. The contraceptive function was observed in studies to be a consistent pattern for this class of medicine, and research explored its use in generally healthy women of reproductive age.

Evidence for Management of Androgen-Related Symptoms

Studies explored the management of conditions characterized by fluctuating or episodic manifestations, such as moderate to severe acne, excessive skin oiliness, and hirsutism. The evidence base related to this use includes Randomized Controlled Trials (RCTs) and Meta-Analyses.

Outcomes Studied in Skin and Hair Trials

For symptoms like acne and hirsutism, research examined changes in objective assessment scores, such as overall lesion counts, severity scores, and measurements related to hair growth. Studies also monitored whether biochemical changes, including shifts in circulating androgen hormone levels and increases in Sex Hormone-Binding Globulin (SHBG), occurred, consistent with the anti-androgenic function being studied. Clinical trials reported measurements related to changes in acne lesion counts and severity scores throughout the study periods, which typically lasted between 6 and 12 months.

What Remains Uncertain in the Research Landscape

Limited information is available from formal RCTs regarding the full long-term evolution of these specific symptoms beyond the initial one-year observation period. Research highlights that a significant portion of the historical evidence describing the anti-androgenic function of Cyproterone acetate relies on combinations that used Ethinyl Estradiol rather than the Estradiol Valerate component found in Femilar. Limited data exists from dedicated, head-to-head research directly comparing the specific long-term profile of the Estradiol Valerate combination across all studied outcomes. Data for certain groups, such as populations with other health conditions (comorbidities), remain insufficient.

Frequently Asked Questions (FAQ)

Common questions about Femilar (FAQ)

Q: How long does it usually take to notice an effect from Femilar?

A: Official product information indicates that when Femilar is used for androgen-dependent conditions like acne or hirsutism, it typically takes at least three months of use before symptom relief is noticeable. The full effect may take longer, and official guidance describes use continuing throughout the prescribed cycle.


Q: Are there any long-term health concerns associated with Femilar use?

A: Regulatory documents detail several serious risks that may be associated with usage, particularly with long-term exposure. These documented risks include associations with Venous Thromboembolism (VTE), Arterial Thromboembolism (ATE), and the potential for Benign or Malignant Liver Tumours and the association with Meningioma.


Q: Does Femilar interact with birth control pills?

A: Femilar is classified as a Combined Hormonal Contraceptive preparation. Because of this, official regulatory labels state that it should not be used in combination with any other hormonal contraceptive preparation.


Q: Can Femilar cause changes in mood or sleep?

A: Yes, official regulatory documents list Depressed mood as a Common adverse reaction. Sleep disturbances are documented as a less frequent, Very rare adverse reaction associated with the use of the medicine.


Q: How often are the side effects of Femilar usually reported?

A: Regulatory documents categorize documented side effects by their frequency of reporting. The majority of reported adverse reactions, such as headaches, nausea, and breast tenderness, are classified as Common, which is the highest frequency category.


Q: What happens if I stop taking Femilar suddenly?

A: Official guidance emphasizes that discontinuation protocols are determined by a healthcare provider. If the medicine is discontinued, any androgen-related symptoms that were being treated, such as acne or excessive hair, may gradually return.


Q: Is it common to have mild headaches when first starting Femilar?

A: Headaches are listed in regulatory documents as a Common adverse reaction associated with this medication. Some official guidance indicates that side effects like headaches and nausea may occur when the patient is first starting the treatment. These effects often lessen over time.


Q: Does taking Femilar affect the results of common lab tests?

A: Hormonal medicines in this class may affect the results of certain lab tests, including those for thyroid function, coagulation (blood clotting) parameters, and lipid (fat) metabolism. These effects should be considered during monitoring.


Q: Is it normal to feel a bit nauseous after taking Femilar?

A: Nausea is listed in regulatory documents as a Common side effect. It is a recognized gastrointestinal symptom associated with this class of medicine.


Q: How does alcohol consumption relate to taking Femilar?

A: General warnings describe avoiding excessive alcohol consumption while taking this medicine. This precaution is often noted due to the potential for alcohol to increase liver strain.


Q: Can Femilar cause weight changes?

A: Yes, regulatory documents list Weight fluctuations, which may include both weight gain or weight loss, as a Common documented adverse reaction. This is a recognized effect associated with this class of medicine.


Q: What should I tell my dentist before a procedure if I'm taking Femilar?

A: Official documents require discontinuing the medicine four weeks prior to major surgery that involves prolonged periods of immobilization due to the risk of blood clots. This information is often shared before any planned medical or surgical procedure.


Q: Is it true that Femilar can cause hair loss?

A: The active ingredient Cyproterone Acetate is known for its anti-androgen effects, which treat excessive hair growth (hirsutism). However, official information notes that changes to how well the hair grows and loss of hair have also been documented as less frequent, Less Common side effects.


Q: Can Femilar be crushed or split for easier swallowing?

A: The official instruction for taking Femilar is to swallow the tablet whole with liquid. Splitting or crushing hormonal combination products is generally described as potentially altering the dose, absorption, or effectiveness of the medicine.


Q: What if I take too much Femilar by mistake?

A: Symptoms of taking too much of this class of medicine typically include nausea, vomiting, and sometimes withdrawal bleeding (vaginal bleeding). The official product label describes that if too many tablets have been taken, it is necessary to contact a healthcare professional.


Q: Are there any restrictions on activity while taking Femilar?

A: Official warnings describe that an individual may experience drowsiness, dizziness, or reduced alertness. Regulatory documents state that caution is needed before driving or operating machinery until an individual knows how they react to the medicine.


Q: What kind of monitoring is typically recommended while on Femilar?

A: Official regulatory guidance recommends regular monitoring by a healthcare provider while using this medicine. This typically includes a physical examination, checking blood pressure, recording weight, and monitoring relevant liver function tests.


Q: What is the research evidence summary for Femilar?

A: Official documents describe the evidence base as being derived from different types of studies. The contraceptive function is supported by Epidemiological Observational Studies, while the use for androgen-related conditions is supported by evidence from Randomized Controlled Trials (RCTs).

How should Femilar be stored and disposed of?

How to Store and Dispose of Femilar

Femilar tablets must be stored strictly according to regulatory guidelines to maintain stability and effectiveness. The official labeled storage temperature requires the tablets to be kept at or below 25 C (77 F), generally corresponding to controlled room temperature. The product must be kept in the original blister pack and outer carton to protect the active ingredients from both light and moisture; do not freeze the medicine.

Storage and Disposal Requirements

As with all prescription medicines, Femilar must be secured and kept out of the sight and reach of children.

For disposal, unused or expired tablets should be managed through a community drug take-back program. If a take-back program is unavailable, official guidance requires mixing the medicine with an unappealing substance, sealing it, and discarding it in the household trash. The medicine must not be thrown into wastewater or household sewers.

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

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