Провирон

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Провирон

Treatment option: Anemia, Infertility, Hypogonadism

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 Провирон

What is Провирон? Defining the Hormonal Agent

Property Description
Active ingredient Mesterolone
Form Tablet (oral preparation)
Pharmacological class Androgen (Synthetic Steroidal Agent)
General purpose To support/restore androgenic activity
Origin Synthetic, 5alpha-reduced testosterone derivative

Провирон is the trade name for a synthetic hormonal agent classified medically as a steroidal androgen, whose core substance is Mesterolone (INN). This medication is an oral preparation, provided as a tablet that contains a single active ingredient. The official classification of Mesterolone within the Anatomical Therapeutic Chemical (ATC) system places it in the broader category of Androgens.

Mesterolone: A Unique Synthetic Androgen Profile

Mesterolone is a chemically derived, synthetic substance, cataloged as an anabolic-androgenic steroid and a specific derivative of dihydrotestosterone (DHT). Its complex chemical structure allows it to be efficiently delivered via the oral route, a key differentiating factor from many injectable androgen therapies.

A critical characteristic distinguishing Mesterolone from many other androgens is that it is structurally non-aromatizable, meaning it is not converted by the body’s enzymes into estrogen, a recognized pharmacological property. This chemical feature ensures that its pharmacological effects are specifically directed toward androgen receptors.

General Function of This Androgenic Agent

The general purpose of the Провирон preparation is to exert an androgenic effect to support or restore physiological functions dependent on sufficient male hormone activity. It works by directly activating androgen receptors, while also demonstrating a significant affinity for Sex Hormone-Binding Globulin (SHBG). By interacting with SHBG, Mesterolone can influence the amount of free, biologically active androgen available in the bloodstream. These actions collectively aim to maintain or stabilize the body's reliance on androgenic stimulation, serving its primary role as a hormonal agent.

What side effects are possible with Провирон?

Possible Side Effects and Safety Information

The safety profile of Провирон (Mesterolone) is officially documented and categorized by regulatory bodies based on the frequency and type of effects observed. The officially listed adverse reactions are typically organized by the physiological system affected.

Documented Adverse Reactions and Frequency

Adverse reactions are classified according to frequency, which indicates how often they have been reported in clinical use:

  • Common: Frequent erections, often observed at the beginning of treatment.
  • Uncommon: Increased libido, nervousness, acne, and weight gain.

Reactions are grouped by System-Organ Class (SOC) and include effects on the Reproductive System, Hepatobiliary Disorders (liver), and Blood and Lymphatic Systems.

Serious Safety Considerations

The regulatory profile explicitly documents serious adverse reactions, primarily associated with long-term exposure. The potential for liver tumors (hepatic neoplasms, both benign and malignant) is noted, particularly with prolonged, high-dose therapy. Additionally, the occurrence of priapism (prolonged, painful erections) is listed as a serious adverse event requiring observation.

Population-Specific Safety Notes and Constraints

The official labeling outlines specific safety constraints for certain patient populations. The medicine is contraindicated in males with carcinoma of the prostate or male breast cancer, and in individuals with previous or existing severe hepatic dysfunction. For older adults, official sources require periodic monitoring of the prostate (DRE and PSA testing) due to the recognized androgen-class risk of prostatic growth. Furthermore, the label mandates periodic checks of haematologic parameters and liver function to monitor for risks such as polycythaemia.

Overdose and Emergency Response

The official regulatory profile for Провирон (Mesterolone) addresses acute over-exposure separately from the risks of chronic misuse. Acute overdosage is generally classified as non-toxic, with documented acute manifestations typically limited to nausea and gastrointestinal upset. No risk of serious harmful effects is expected following the single, accidental ingestion of a multiple dose.

However, chronic and excessive use of hormonal substances like Mesterolone is associated with severe hepatic effects, including the potential for liver tumors, and an increased cardiovascular risk. An increased consideration for prostatic hyperplasia and prostatic cancer in elderly males (over 65 years) is noted in the context of excessive use.

When to Seek Immediate Help

Regulatory guidance mandates that immediate medical attention is required for any suspected overdose, regardless of the presence of immediate discomfort. Urgent medical attention or hospitalisation is specifically required if severe stomach pain or tenderness occurs and does not subside, as this may be a warning sign of severe internal complications.

In the case of acute intoxication, management is strictly supportive. No specific antidote is known; therefore, treatment is limited to addressing the symptoms as they arise.

Therapeutic Uses of Провирон

What Провирон Treats: Main Uses and Benefits

Therapeutic Indications and Symptom Support

The therapeutic use of Провирон (Mesterolone) is primarily focused on addressing conditions presenting with systemic or localized discomfort stemming from insufficient male hormone activity. The medicine is considered relevant for clinical settings that involve androgen deficiency.

It is commonly applied as substitution therapy for clinically confirmed states of male hypogonadism and androgen deficiency. It may assist with managing symptoms associated with male climacteric syndrome and specific forms of male infertility related to oligozoospermia or insufficient Leydig-cell secretion.

The medication helps address symptom clusters that may become intense or disruptive, such as disturbances of libido and potency, along with neuro-psychological symptoms like irritability, sleep disturbances, and easy fatigability. Its supportive role contributes to improved comfort during symptomatic periods and assists with functional stability.

It provides supportive relief when symptoms interfere with routine activities.


Androgen Deficiency Symptom Support

  • Androgen Deficiency and Hypogonadism: The medication is used in situations involving certain distressing symptoms, where it supports patients by easing the overall symptom burden.
  • Sexual Function: Plays a role in managing disturbances of libido and potency linked to hormonal imbalance.
  • Vitality: Supports general well-being during symptomatic phases such as fatigue and reduced efficiency.

Eligibility and Restrictions for Use

Who Can and Cannot Use Провирон (Mesterolone)?

Провирон (Mesterolone) is a medication with strictly defined eligibility rules based on official regulatory labeling. Use is primarily limited to the adult male population for androgen replacement therapy in confirmed cases of male hypogonadism.


Contraindicated Populations

Regulatory authorities strictly prohibit the use of Mesterolone for several populations. The medicine must not be used by:

  • Women (female patients).
  • Male patients with Carcinoma of the Prostate or Male Breast Cancer.
  • Patients with previous or existing Liver Tumours.
  • Patients with known Hypersensitivity to Mesterolone or any of its inactive ingredients.

Eligibility Restrictions

Use in certain patient groups is subject to explicit restrictions and mandatory supervision:

  • Children and Adolescents: Use is not recommended as safety and efficacy have not been established in the pediatric population.
  • Long-term use requires mandatory, regular monitoring of prostate status and liver function.
  • Patients with pre-existing Cardiac, Renal, or Hepatic Disease must be supervised closely due to the risk of fluid retention.

What should I know about interactions with other medicines?

The official regulatory profile for Провирон (Mesterolone) focuses on pharmacodynamic interactions that may potentiate the effects of certain co-administered medicinal products. Information concerning drug interactions is based strictly on descriptions found in authoritative government regulatory documents.

Documented Interactions and Effect on Co-Administered Agents

Co-Administered Agent Category Officially Described Interaction Outcome
Oral Anticoagulants (e.g., Coumarin derivatives) May increase the anticoagulant activity (potentiation), potentially requiring close monitoring of coagulation status.
Corticosteroids (Glucocorticoids) Co-administration may lead to an additive increase in the risk or severity of edema (fluid retention).
Antidiabetic Agents (e.g., Insulin, oral hypoglycemics) May increase the hypoglycemic activity of these medicines.

Absence of Documented Regulatory Restrictions

Interaction Type Regulatory Status (Restrictions not specified)
Metabolic (CYP) / Transporter No specific interactions formally documented as requiring mandatory dose adjustments of co-administered medicines.
Food / Alcohol / Herbal Products No explicit regulatory restrictions documented regarding co-administration with food, alcohol, or specific herbal products.
Timing Requirements No mandatory separation windows are listed for co-administered medicinal products.

Interaction Context

The overall structure of the regulatory profile is centered on pharmacodynamic effects. Official labeling notes that the risks and systemic effects related to the medicine may be heightened in individuals with severe hepatic impairment (liver disease).

Mechanism of Action

How Провирон Works (Mechanism of Action)

Провирон (Mesterolone) exerts its pharmacodynamic effects through three distinct molecular mechanisms within the endocrine system. The primary action involves functioning as a direct agonist of the Androgen Receptor (AR). Upon binding to the AR, Mesterolone forms a ligand-receptor complex that translocates to the cell nucleus, initiating the transcription of androgen-responsive genes. This intracellular cascade influences the regulation of hormone-dependent physiological processes.

Second, the drug modulates the activity of Sex Hormone-Binding Globulin (SHBG), a circulating carrier protein. By competitively binding to or influencing SHBG, Mesterolone alters the proportion of protein-bound hormones, mechanically increasing the free and biologically active fraction of endogenous androgens, thereby modifying humoral signaling dynamics.

Third, Mesterolone exhibits an inhibitory effect on the Aromatase enzyme cascade (CYP19A1). This interaction blocks the molecular conversion of androgens into estrogens, contributing to a reduction in estrogenic pathway activation and influencing the overall balance of sex hormones.

Dosage and Administration Information

How to use Провирон: Official Administration Guidelines

This structure formalizes the usage instructions for Провирон (Mesterolone), adhering to the prescribing information.


Administration Scope

Instruction Entity Detail
Route of administration Oral
Dosing schedule Initial Dosing: Typically 75 mg to 100 mg per day. Maintenance Dosing: Reduced to 25 mg to 75 mg daily.
Timing in relation to meals (if applicable) Should be taken with liquid and may be taken with food or after meals to promote tolerance.
Preparation requirements (if applicable) Tablets are to be swallowed whole.
Age-group administration rules Instructions primarily cover adult male use.
Missed-dose rules If a dose is missed, do not take a double dose to compensate.
Special procedural conditions The total daily dose is frequently administered in divided doses (two to three times per day).

Resulting Procedural Structure

Official step sequence:

  • The oral tablet is swallowed whole with liquid, optionally with or after a meal.
  • The medicine is initiated at a higher daily dose (e.g., 75 mg to 100 mg), often administered in divided doses across the day.
  • Following the initial treatment phase and a satisfactory response, the dose is reduced to a lower, individualized maintenance range for continued, long-term therapy.

Connection to the overall use protocol (2–4 sentences): This procedural structure dictates that the medicine must be taken by mouth and establishes a clear progression from an initial commencement phase to a reduced maintenance amount. The protocol further mandates that the daily dose is typically split into smaller administrations and defines the use pattern as either continuous for long-term support or cyclical for specific indications such as oligozoospermia.

Recent Clinical Evidence

Research evidence / Overview of studies for Провирон


Evidence for Mesterolone in Male Hypogonadism

The research examined the use of Mesterolone in the context of substitution therapy for clinically confirmed androgen deficiency. Clinical trials and comparative studies have been used in research exploring how symptoms change over time in adult men with a loss of gonadal function. Researchers studied outcomes related to systemic or functional imbalance, including measures of sexual function and tracking of general well-being.

Older clinical data research describes patterns observed in measures related to certain deficiency symptoms, such as outcomes related to physical discomfort like easy fatigability and outcomes reflecting daily functioning like poor concentration. Some comparative studies tracked different outcomes for other androgen therapies in these populations.


Evidence for Addressing Libido and Potency Disturbances

For disturbances of libido and potency that was associated with androgen deficiency, research has explored outcomes related to specific sexual functions. Clinical trials were applied in studies examining patient-reported experiences regarding changes in libido and erectile function. The research examined adult males presenting with these specific function disturbances, where androgen deficiency was a consideration.

Evidence is limited in determining the extent to which hormonal factors alone were the primary driver in the reported outcomes, as such disturbances may be linked to multiple factors beyond hormone levels.


Evidence and Uncertainty in Male Infertility (Oligozoospermia)

Mesterolone was studied for male infertility, specifically in men with low sperm count (oligozoospermia) or insufficient Leydig-cell secretion. Research designs for this indication include Randomized Controlled Trials (RCTs) and systematic reviews that monitored changes in semen parameters and clinical outcomes such as pregnancy rates.

The findings were mixed regarding its use in idiopathic oligozoospermia. Multiple controlled studies have reported inconsistent or negligible changes in sperm count and quality compared to placebo, and the research does not determine a consistent pattern in pregnancy rate measurements across the full evidence base. These results highlight that the overall certainty remains low for this specific clinical situation.


Research Gaps and Areas of Uncertainty

The research highlights what is known — and what is still uncertain — about Mesterolone. A key limitation is that evidence quality varies across studies, with many foundational studies being historical. Comparative evidence is lacking for Mesterolone against other established therapies for certain deficiency symptoms. Furthermore, the long-term effects are not fully established across all indications, and research on extended continuous use is an area where data are still emerging.

Frequently Asked Questions (FAQ)

Common questions about Провирон (FAQ)

Q: What are the primary medical uses of Провирон as described in official documents?

A: According to the official product information, Провирон is primarily indicated for substitution therapy in men with androgen deficiency due to hypogonadism (low male hormone function). It is also described as a supportive treatment for certain forms of male infertility.

Q: What are the official indications for using Провирон in men?

A: Official regulatory documents state that Провирон is used to treat male patients requiring substitution therapy for androgen deficiency. This includes managing conditions like male hypogonadism and providing supportive treatment for some types of male infertility.

Q: Is Провирон classified as a type of testosterone replacement therapy?

A: Провирон is chemically a synthetic steroidal androgen, and it is used to support and restore male hormone activity. While it is sometimes grouped with 'androgen replacement' treatments, some clinical sources indicate it is not considered a complete substitute for testosterone.

Q: Why is Провирон specifically intended for use in male patients only?

A: Regulatory documents state that the medicine is contraindicated for use in females. This is due to the recognized risk of masculinization (development of male characteristics), which can affect a fetus or infant.

Q: Why is Провирон sometimes described as having a 'weak anabolic effect'?

A: Regulatory and scientific documents describe the medicine as having a weak anabolic (tissue-building) effect. This is because it is rapidly inactivated by specific enzymes within the skeletal muscle tissue.

Q: What is the role of Провирон in stimulating the development of secondary male sex characteristics?

A: The general function of this medicine, as an androgen, is to support physiological functions dependent on male hormones. This includes the development and long-term maintenance of secondary male sex characteristics in patients with deficiency.

Q: What is the difference between Провирон and other androgen-based medicines available on the market?

A: A key distinction of Провирон is that its active substance, Mesterolone, is non-aromatizable. This means that unlike some other androgens, it cannot be converted by the body's enzymes into estrogen.

Q: Can Провирон cause any changes to a patient's mood or psychological state?

A: The official product information documents that changes in mood and mental state may occur. Reported side effects include nervousness, irritability, aggression, and in some cases, depression.

Q: Does Провирон affect hair growth or the possibility of scalp hair loss?

A: Official safety data notes that the medicine can influence hair and skin health. Documented side effects include the development of acne, increased body hair growth (excessive hairiness), and the possibility of scalp hair loss (alopecia).

Q: Is Провирон known to affect blood pressure?

A: High blood pressure is not listed as a common side effect of this medicine. However, official information indicates that caution and medical monitoring are advised for patients with a history of high blood pressure, due to the general risks associated with the androgen class of drugs.

Q: What are the potential effects of Провирон on a person's cholesterol or blood lipid profile?

A: Official regulatory sources indicate that this medicine can cause changes to the blood lipid profile. Specifically, it has been observed to reduce levels of 'good' HDL cholesterol while potentially increasing levels of 'bad' LDL cholesterol.

Q: Are there specific symptoms of a serious adverse reaction that require immediate medical attention?

A: Official patient leaflets specify certain signs that may warrant immediate medical attention. These include severe stomach pain or tenderness (which may indicate a potential liver issue) and the occurrence of a prolonged and painful erection (priapism).

Q: What are the reported effects of Провирон on sleep or sleep disturbances?

A: While general sleep disturbances are not explicitly listed as common side effects, the medicine does list nervousness and irritability. Additionally, patients with a history of breathing problems during sleep (sleep apnoea) are noted in regulatory documents to require specific medical caution.

Q: Does Провирон have a high risk of drug dependency or habit formation?

A: Regulatory authorities classify this medicine as an Anabolic Androgenic Steroid (AAS). Official warnings specifically state that this class of medicine has been subject to abuse and carries a known risk of developing dependency.

Q: Are there any documented cases of severe allergic reactions to Провирон?

A: The product information includes general allergic signs such as itching, rash, fever, and hives as potential adverse effects. As with any medication, if a patient experiences severe signs of allergy, they should seek medical attention.

Q: Is Провирон safe for use in men who have been diagnosed with diabetes?

A: Official information indicates that this medicine may increase the activity of anti-diabetic agents, which are used to lower blood sugar. Therefore, patients with diabetes often undergo close monitoring to help ensure their blood sugar levels remain stable when starting this medication.

Q: Is the treatment with Провирон generally considered a long-term or short-term therapy?

A: The procedural structure described in the official guidelines suggests that Провирон is often used for long-term support. After an initial phase with a higher dose, treatment generally continues with a lower, individualized maintenance dose.

Q: Does Провирон usage require special monitoring of the liver or kidneys?

A: Official safety guidelines mandate periodic monitoring of liver health and the prostate gland as a precaution. Routine monitoring of kidney function is not universally required, though patients with pre-existing kidney conditions are noted to need caution.

Q: Does the time of day a patient takes Провирон matter for its effectiveness?

A: Official guidelines state that the medicine is generally taken at approximately the same time each day. This practice is primarily recommended to maintain steady levels and support compliance with the treatment schedule.

Q: How is Провирон processed and eliminated by the body?

A: The medicine is rapidly absorbed and then metabolized (broken down) primarily in the liver. Official pharmacokinetic data shows that the majority of the drug (around 80% of the dose) is then eliminated through the urine as inactive metabolites.

Q: What information is available regarding the effect of Провирон on a patient's energy levels?

A: Official product information lists the possibility of changes to a patient’s energy and activity levels. This includes reports of both increased or decreased energy, as well as rapid fatigability.

Q: Is it true that Провирон is only used for men with a complete lack of natural male hormones?

A: According to official documents, the medicine is indicated for substitution therapy in men with 'androgen deficiency' or 'loss of gonadal function.' This typically covers varying degrees of low hormone levels, not exclusively a complete absence of natural male hormones.

Q: Why is Провирон not recommended for adolescents or individuals under the age of 18?

A: Regulatory warnings state that using the medicine during puberty can cause two specific developmental issues. These are the risk of stunting a patient’s growth and the potential for premature puberty.

Q: Does taking Провирон affect the production of natural hormones in the body?

A: Research suggests Mesterolone has a limited or lesser suppressive effect on the pituitary gonadotropins (FSH and LH) compared to certain other androgens, potentially resulting in less inhibition of the body's natural hormone production.

Q: Is Провирон effective for erectile dysfunction not directly caused by androgen deficiency?

A: Official research evidence notes that efficacy is limited when hormonal factors alone are not the main cause of the disturbance. Therefore, its intended effectiveness relates specifically to sexual function issues linked to androgen deficiency.

How should Провирон be stored and disposed of?

How to Store and Dispose of Proviron (Mesterolone)

Official Storage Requirements

Proviron tablets must be stored at a temperature not exceeding 30 C in a cool, dry place, strictly following the regulatory mandate to maintain product stability. To prevent environmental damage from dampness and heat, the medicine should not be stored in a car, in a bathroom, or near a sink. It is a regulatory requirement that the tablets be kept in their original pack until the time of use and be stored out of the sight and reach of children.

Disposal Instructions

Unused or expired Proviron must not be disposed of via household waste or wastewater to prevent environmental contamination. The official instruction is to return any unused medicine to a pharmacist for appropriate pharmaceutical waste disposal, adhering to local regulations for controlled waste.

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

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