Stanozolol

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Stanozolol

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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 Stanozolol

Quick Facts

Property Description
Active ingredient Stanozolol (17alpha-methylstanozolol)
Form Oral tablets, Injectable aqueous suspension
Pharmacological class Anabolic-Androgenic Steroid (AAS)
General purpose Promote tissue building, counteract catabolism
Origin Synthetic, derived from dihydrotestosterone (DHT)

Stanozolol: Pharmacological Classification and Identity

Stanozolol is a powerful, synthetic prescription drug classified as an Anabolic-Androgenic Steroid (AAS). The substance is chemically identified by the International Nonproprietary Name (INN) Stanozolol. Its origin is purely synthetic, acting as a derivative of the naturally occurring hormone dihydrotestosterone (DHT). This structural modification is clinically recognized for enhancing its therapeutic potential compared to non-alkylated androgens.

The compound’s defining characteristic is its unique 17alpha-alkylation, a structural alteration that grants it high oral bioavailability and resistance to breakdown by the liver. This structural difference, which includes a fused pyrazole ring, makes Stanozolol stand out among other AAS formulations by generally exhibiting a favorable ratio of tissue-building (anabolic) properties relative to its masculinizing (androgenic) effects.

Composition and Available Pharmaceutical Forms

Stanozolol is primarily supplied as a single-ingredient product in two distinct identity forms: oral tablets and an injectable aqueous suspension. The tablets contain the 17alpha-methylstanozolol active compound. The injectable form is noteworthy because it is prepared as a milky-white aqueous suspension—a fine dispersion of solid Stanozolol particles in water—rather than the oil-based solutions common to many other injected steroids. This compositional distinction allows for both convenient oral administration and a sustained release profile when administered via intramuscular injection.

General Purpose and Primary Anabolic Action

The general purpose of Stanozolol is to promote robust tissue building and counteract states of severe physical wasting (catabolism) through enhanced protein synthesis. The drug achieves this by binding to androgen receptors, which triggers an intensified anabolic action, maximizing the body's nitrogen retention and accelerating the construction of cellular protein. This powerful physiological signaling is leveraged in medicine to support strength and overall physical recovery, particularly in patient scenarios involving significant loss of lean body mass associated with chronic or debilitating illnesses.

What side effects are possible with Stanozolol?

Possible Side Effects and Safety Information

The safety profile of Stanozolol, an anabolic-androgenic steroid, is strictly defined by regulatory documents, emphasizing the potential for serious, life-altering, and time-dependent adverse reactions. This profile is consistent across official regulatory bodies such as the FDA and EMA.


Adverse Reaction Categories

Adverse reactions are formally categorized by system-organ class, with major concerns centered on the Hepatobiliary Disorders (liver), Reproductive System Disorders, and Vascular Disorders.

Classification Common Adverse Reactions Rare, Serious Adverse Reactions
Hepatobiliary (Not common) Cholestatic Hepatitis, Jaundice, Peliosis Hepatis, Hepatic Neoplasms
General Acne (new or worsening), Insomnia, Headache Edema with Congestive Heart Failure (in susceptible patients)
Reproductive Changes in sexual desire Irreversible Virilization (in females), Prostatic Hypertrophy (in elderly males)

Safety Considerations and Restrictions

Serious Hepatic Events, including liver tumors and peliosis hepatis, are explicitly documented as being associated with prolonged administration and high-dose therapy. Due to the risk of severe liver toxicity, mandatory periodic monitoring of liver function tests is an essential requirement noted in regulatory documents.

Population-specific risks are highly defined:

  • Female Patients: The label notes a significant risk of virilization (masculinizing effects), with certain changes like voice deepening and clitoral enlargement possibly being irreversible.
  • Prepubertal Patients: There is a documented risk of premature cessation of linear bone growth due to early epiphyseal closure.
  • Pregnancy: The medication is contraindicated (Pregnancy Category X) due to the known potential for fetal harm.

Overdose and Emergency Response

Overdose and When to Seek Help: Official Regulatory Guidance

Regulatory agencies provide specific, limited information regarding acute Stanozolol overdose. The official guidance focuses primarily on mandatory action due to a lack of defined acute symptoms.

Documented Overdose Profile

Feature Official Regulatory Statement
Documented Symptoms Symptoms of acute overdose are not formally known or specified in the primary regulatory labeling. Non-specific effects such as nausea and gastrointestinal upset may occur.
Severity Acute overdose is officially stated to be unlikely to threaten life.
Antidote Status There is no specific antidote for Stanozolol overdose documented in the official prescribing information.

Emergency Actions Required

When a Stanozolol overdose is suspected, official regulatory documentation mandates specific help-seeking actions. These instructions are the primary guidance provided in the event of an overdose.

  • Required Action: The mandatory instruction is to contact an emergency room or a poison control center for advice immediately if an overdose is suspected.
  • Management: Management is generally described as being limited to supportive care.

This structure reflects the official position that emergency consultation is required because acute manifestations are non-specific and a specific antidote does not exist.

Therapeutic Uses of Stanozolol

Main Therapeutic Uses and Benefits of Stanozolol

Stanozolol is considered relevant for the long-term management of conditions characterized by periods of heightened symptoms . It is commonly used in therapeutic domains where supportive symptom management is appropriate, and is considered relevant in conditions presenting with systemic or localized discomfort, such as hereditary angioedema (HAE) and specific types of chronic physical wasting or muscle loss due to extended illness.

Its therapeutic application is considered relevant in contexts marked by increased discomfort. It is applied in addressing symptom clusters that may become intense or disruptive, such as recurrent episodes of localized swelling or symptoms related to systemic imbalance and loss of strength.

“The medication may assist with managing symptoms that create noticeable physiological strain and loss of strength, supporting the patient during difficult episodes.”

This supportive role assists with maintaining functional stability when symptoms are more noticeable, contributing to improved comfort during symptomatic periods.


Quick Fact: Supportive Management for Recurrent Swelling Stanozolol is commonly used to help with symptom clusters related to recurrent, unpredictable swelling, assisting patients in coping more steadily with these episodic manifestations.

Eligibility and Restrictions for Use

Who Can and Cannot Use Stanozolol?

Eligibility for Stanozolol is strictly determined by regulatory labeling, which outlines specific contraindications and patient restrictions.

Absolute Contraindications

Stanozolol is contraindicated and must not be used in the following patient populations, as stated in official prescribing information:

  • Patients with diagnosed carcinoma of the prostate or carcinoma of the breast.
  • Patients with hypercalcemia (high levels of calcium in the blood).
  • Females who are pregnant or who may become pregnant during treatment.
  • Patients with severe liver disease or known hypersensitivity to the drug.

Restrictions and Special Considerations

Use is restricted or requires special monitoring in several other groups due to potential risks, as documented by regulatory authorities:

  • Patients with pre-existing hepatic (liver) or renal (kidney) impairment.
  • Patients with cardiovascular disease, a history of a heart attack, high cholesterol, or Diabetes Mellitus.
  • Use in the pediatric population requires caution and monitoring of bone development to mitigate the risk of premature epiphyseal closure.
  • For females who are breastfeeding, use is not recommended due to insufficient data on excretion into human milk.

What should I know about interactions with other medicines?

Stanozolol is known to interact with several classes of medications, which can alter its effectiveness or significantly increase the risk of adverse effects. It is crucial to inform a healthcare provider of all prescription drugs, over-the-counter medicines, and supplements being taken.

Major Drug Interactions

Drug Class Potential Interaction Monitoring Required
Oral Anticoagulants (e.g., Warfarin) Stanozolol can potentiate the effect of blood thinners, significantly increasing the risk of bleeding. Close monitoring of Prothrombin Time and International Normalized Ratio (INR); anticoagulant dose adjustment.
Corticosteroids (e.g., Prednisone) Concurrent use can increase the risk of edema (fluid retention), particularly in patients with pre-existing heart or liver conditions. Monitoring for signs of fluid retention and hypertension.

Moderate Drug Interactions

Drug Class Potential Interaction Monitoring Required
Antidiabetic Agents (e.g., Insulin, Sulfonylureas) Stanozolol can lower blood glucose levels, which may lead to hypoglycemia when combined with diabetes medicines. Frequent self-monitoring of blood glucose; possible dosage adjustment of antidiabetic agents.

Impact on Laboratory Tests

Stanozolol may interfere with several laboratory tests, including those for thyroid function by decreasing levels of thyroid-binding globulin, and tests for coagulation factors. It may also affect serum lipid profiles by lowering High-Density Lipoprotein (HDL) and elevating Low-Density Lipoprotein (LDL) levels. These changes can increase the risk of cardiovascular disease and require regular monitoring of blood lipids.

Mechanism of Action

Stanozolol functions primarily as a synthetic anabolic-androgenic steroid (AAS), structurally derived from dihydrotestosterone. Its mechanism of action involves binding as an agonist to the intracellular androgen receptor (AR), found predominantly in target tissues such as skeletal muscle and bone.

Upon ligand binding, the activated AR complex undergoes translocation into the cell nucleus. Inside the nucleus, the complex binds to specific Androgen Response Elements (AREs) in the promoter regions of target genes. This binding event modulates gene transcription, leading to an increased synthesis of specific messenger RNA (mRNA) molecules, which subsequently drives the enhanced translation of structural proteins.

This cascade results in a systemic modulation of nitrogen balance and an increase in protein synthesis within skeletal muscle tissue, a process termed anabolism. In bone tissue, stanozolol modulates factors that influence osteogenic differentiation and bone mineralization. Stanozolol also exhibits non-genomic effects, including the stimulation of blood fibrinolysis and the enhancement of C1-esterase inhibitor production via hepatic synthesis, which contributes to the modulation of the complement and contact systems.

Dosage and Administration Information

Administration Scope

Instruction Detail
Route of administration The medicine is administered via the oral route in tablet form.
Dosing schedule (for HAE prophylaxis) Initial Dose: Prescribing information specifies 2 mg taken three times per day. Maintenance Dose: The dosage is systematically reduced to the minimum effective amount, typically ranging from 0.5 mg to 2 mg daily, for long-term use.
Timing in relation to meals Stanozolol may be taken with or without food.
Preparation requirements The tablet must be ingested with a full glass of water.
Age-group administration rules Use in pediatric populations requires continuous monitoring, including evaluation for potential acceleration of bone maturation.
Missed-dose rules If a dose is missed and it is close to the next scheduled dose, the label instructs the individual to skip the missed dose and not take a double dose.
Special procedural conditions The drug requires routine clinical evaluation to guide the dose adjustment and establish the minimal dose necessary for ongoing use.

Procedural Structure

The official use of the drug follows a specific two-phase procedural structure. Administration begins with the defined initial dosage taken three times daily. This is followed by a mandated, gradual dose reduction, occurring at intervals of one to three months, with the goal of establishing the lowest possible effective maintenance dose. This sequence, combined with specific intake and missed-dose rules, formalizes the precise procedural steps for administering the medicine, ensuring the protocol governs how the medicine is introduced, adjusted, and continued over time.

Recent Clinical Evidence

Research Base for Hereditary Angioedema (HAE) Prophylaxis

Stanozolol was studied for its application in the routine prevention of swelling attacks in conditions characterized by fluctuating or episodic manifestations, specifically Hereditary Angioedema (HAE). Research for this indication involved a combination of smaller initial clinical trials and, notably, long-term observational settings that provided follow-up on patient groups for many years. These studies focused on outcomes describing episodic changes, such as the frequency and severity of HAE swelling attacks, and monitored outcomes related to acute physical manifestations in adults and adolescents. The findings describe patterns observed over these extended periods, with documented long-term observations up to 40 years. However, this evidence is limited in terms of size, as the foundational reports included modest sample sizes. Consequently, there is limited information available from recent comparative evidence that directly examines Stanozolol against newer drug therapies used for HAE today.

Research Base for Chronic Physical Wasting and Anabolic Support

Stanozolol was evaluated in the context of chronic physical wasting or muscle loss, where research examined questions related to tissue preservation and anabolic action. The evidence available for this use is limited and primarily consists of Systematic Reviews that consolidate data across the broader class of Anabolic-Androgenic Steroids (AAS). Pre-clinical studies were also conducted to explore physiological changes. Research in this area explored surrogate measures, such as changes in Lean Body Mass (LBM) and Fat-Free Mass (FFM). The available data show patterns related to measured changes in muscle mass in the study groups. However, the evidence for Stanozolol specifically is limited compared to the data for the AAS drug class.

What Research Gaps and Uncertainties Remain

Research provides context but not individual predictions, and evidence highlights what is known—and what is still uncertain. For both indications, evidence quality varies across studies, and the sample sizes were modest in many foundational reports. A major gap for HAE is the lack of comparative evidence against newer treatments. For chronic wasting, the primary uncertainty is the reliance on data extrapolated from the broader AAS drug class. Additionally, a persistent limitation is that research focusing on outcomes reflecting daily functioning or long-term quality of life is limited.

Frequently Asked Questions (FAQ)

Common questions about Stanozolol (FAQ)


Q: Is Stanozolol considered a controlled substance?

A: According to the U.S. Drug Enforcement Administration (DEA), Stanozolol is classified as a Schedule III controlled substance. This classification is assigned because the medication is an anabolic steroid with a recognized potential for misuse or dependence. Official documents and regulatory bodies group these substances together based on their chemical structure and risk profile.


Q: Can women use Stanozolol?

A: Eligibility for Stanozolol in women is strictly defined by regulatory guidelines due to significant risks. The medication is absolutely contraindicated during pregnancy due to the known potential for fetal harm. Use in non-pregnant females for approved conditions is noted to carry a serious risk of virilization (masculinizing effects), which regulatory documents note may be irreversible. Any prescription for this population is subject to the specific monitoring requirements described in the official safety information.


Q: What is the maximum duration someone can be treated with Stanozolol?

A: Regulatory documents outline that Stanozolol treatment for conditions like Hereditary Angioedema (HAE) often involves a long-term maintenance phase. The label indicates this phase is achieved by reducing the dose to the lowest necessary amount. The regulatory label itself does not specify a maximum duration limit or cap for treatment.


Q: Can Stanozolol affect blood pressure?

A: Regulatory information indicates that Stanozolol can increase the risk of fluid retention (edema), particularly when used concurrently with other medications like corticosteroids. This fluid retention may contribute to or worsen hypertension (high blood pressure) in susceptible patients. Official information states that patients with pre-existing cardiovascular conditions are subject to special monitoring requirements for blood pressure and fluid retention during treatment.


Q: Can Stanozolol interact with dietary supplements?

A: Official prescribing information notes that supplements may alter the drug’s effectiveness or increase the risk of adverse effects, and regulatory documents require disclosure to a healthcare provider. Although the label primarily details interactions with prescription drugs like blood thinners and antidiabetic agents, the general warning acknowledges the risk of supplement interaction.


Q: Are there specific lab tests required before starting Stanozolol?

A: While the label strongly mandates periodic monitoring of liver function tests and blood lipids during treatment, official documents indicate that a full clinical evaluation is required before starting the medicine. This evaluation includes establishing a pre-treatment baseline for comparison with continuous monitoring.


Q: Does Stanozolol affect fertility in men or women?

A: Regulatory documents note that Stanozolol carries significant risks to the reproductive system, including irreversible masculinizing effects (virilization) in women and prostatic hypertrophy in elderly males. While the label does not explicitly detail the drug's direct effect on fertility (the ability to conceive), these serious reproductive adverse effects are recognized in official safety summaries.


Q: Is Stanozolol the same thing as Winstrol?

A: Yes, the name Winstrol is the registered brand name under which the active ingredient, Stanozolol, was historically marketed for human use. Stanozolol is the chemical substance name, also known as the International Nonproprietary Name (INN).


Q: How quickly does Stanozolol start to work?

A: The official product information does not typically emphasize a rapid onset time for the therapeutic effects of Stanozolol in its approved uses. While pharmacokinetic studies may estimate the time to peak concentration in the blood, regulatory documents focus more on the systemic effects that are often realized over a longer course of treatment.


Q: How long do the effects of Stanozolol last?

A: The duration of Stanozolol's presence in the body is determined by its half-life, which is the time required for half the dose to be eliminated. Official pharmacokinetic data suggests that the drug has a prolonged half-life, meaning the substance remains in the system for a sustained period after administration.


Q: Is Stanozolol banned for athletes in sports?

A: Yes, official anti-doping authorities, such as the World Anti-Doping Agency (WADA), explicitly prohibit Stanozolol for athletes at all times. The substance falls under the category of Anabolic Androgenic Steroids (AAS), which are banned in competitive sports.


Q: Does Stanozolol cause hair loss?

A: Stanozolol is an anabolic-androgenic steroid, and the official label notes side effects related to its androgenic (masculinizing) properties. Specifically, regulatory documents list hair changes such as hirsutism (increased body hair) in females. The potential for male-pattern hair loss is also a recognized androgenic effect of this drug class.


Q: Can Stanozolol affect mood or cause anxiety?

A: The official list of adverse reactions includes neurological side effects such as insomnia (difficulty sleeping) and headache. While severe mental status changes are addressed as part of the overall risk profile for anabolic steroids, specific terms like 'anxiety' or 'mood changes' may not be explicitly listed in the general adverse reaction sections.


Q: Is it normal to feel nausea after taking Stanozolol?

A: Nausea is listed in official documentation as a potential symptom of serious adverse hepatic (liver) events. Official safety information notes that if nausea is experienced along with other symptoms, such as abdominal pain or dark urine, these may be signs of liver toxicity. This requires immediate reporting to a healthcare professional as noted in regulatory documents.


Q: Is there a generic version of Stanozolol available?

A: Stanozolol is the active chemical substance, which can be sourced as a generic ingredient. However, the commercial tablet product (Winstrol) that contained Stanozolol was discontinued. This means that generic equivalents of the previously approved tablet product are not widely marketed.


Q: Does Stanozolol interact with common painkillers like ibuprofen?

A: Official drug interaction lists focus primarily on major and moderate interactions, such as those with blood thinners, corticosteroids, and antidiabetic agents. Common non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are generally not listed as a major or moderate interaction in regulatory documents.


Q: What are the signs of a serious allergic reaction to Stanozolol?

A: Official drug safety information describes the signs of a serious allergic reaction, also known as hypersensitivity. These can include difficulty breathing, swelling of the face, lips, tongue, or throat, or the sudden appearance of hives.


Q: Why is Stanozolol sometimes prescribed for certain types of anemia?

A: In some regions and historically, Stanozolol was indicated as an anabolic agent to support treatment for certain refractory anemias (anemias that do not respond to standard therapy). This use is based on the drug's ability to stimulate the production of red blood cells, a process known as erythropoiesis.


Q: How is Stanozolol eliminated from the body?

A: According to official pharmacokinetic information, Stanozolol is extensively metabolized (broken down) by the liver. The resulting metabolites are then primarily eliminated from the body via excretion in the urine and feces.


Q: Does Stanozolol have a risk of dependence or misuse?

A: Yes, regulatory bodies recognize that Stanozolol, as an anabolic steroid, carries a potential for misuse and psychological or physical dependence. This recognition is the basis for its classification as a controlled substance.


Q: What should be done if a person suspects an overdose of Stanozolol?

A: Official safety guidance emphasizes that in the event an overdose is suspected, contacting a poison control center or emergency medical services for professional medical advice is required.


Q: Is Stanozolol approved for veterinary use as well?

A: Yes, regulatory bodies, including the FDA, have approved Stanozolol for specific applications in veterinary medicine. These approved uses often involve promoting weight gain, stimulating appetite, or improving muscle condition in certain animal species.


Q: What happens when Stanozolol is stopped suddenly?

A: Abrupt cessation of anabolic steroids is officially associated with the potential for psychological and physical withdrawal symptoms. Official product information suggests that any change in administration, including stopping the drug, must be managed by a healthcare provider.


Q: How long does Stanozolol stay detectable in the system?

A: Detection time is highly variable and depends on the specific analytical test used (e.g., in a doping context) and the form of the drug administered. Regulatory pharmacokinetic data suggests a prolonged presence of the drug in the body, but specific detection windows are not fixed on human drug labels.

How should Stanozolol be stored and disposed of?

How to Store and Dispose of Stanozolol

Stanozolol must be stored according to official regulatory specifications to maintain its stability.

Storage Requirements

Detail Required Condition
Temperature Store at Controlled Room Temperature (between 15 C and 30 C or 59 F and 86 F).
Protection Must be protected from excessive heat, moisture, and direct light; do not freeze.
Container Keep in a tight, light-resistant container.
Safety Must be kept out of the sight and reach of children.

Disposal Instructions

Unused or expired Stanozolol must be handled as pharmaceutical waste. Dispose of the medication in accordance with local requirements and official guidelines. It is typically specified that the product should not be disposed of via wastewater or regular household waste.

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

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