Generic STANOZOLOL INN entry, pharmaceutical patent expiration information and freedom to operate

Sponsor	Phase
Fundação de Amparo à Pesquisa do Estado de São Paulo	Phase 4
Federal University of São Paulo	Phase 4

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Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Lundbeck Inc	WINSTROL	stanozolol	TABLET;ORAL	012885-001	May 14, 1984		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Exclusivity Expiration

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Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Lundbeck Inc	WINSTROL	stanozolol	TABLET;ORAL	012885-001	May 14, 1984	3,704,295	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>Patent No.	>Patent Expiration

Last updated: September 2, 2026

Stanozolol is a mature, low-revenue pharmaceutical with limited legitimate medical demand, no meaningful remaining patent exclusivity, and a larger illicit market than its approved therapeutic market. U.S. commercial activity is concentrated in small generic supplies, compounding, specialty distribution, and veterinary or international channels. Public companies do not generally report stanozolol revenue separately, so no audited global product-market figure is available. Its financial trajectory is best described as long-term erosion from branded sales toward a fragmented, compliance-heavy commodity market.

What is the current market position of stanozolol?

Stanozolol is a synthetic anabolic steroid derived from dihydrotestosterone. It has been marketed under the brand name Winstrol and is available in oral and injectable forms in various jurisdictions. In the United States, stanozolol is a Schedule III controlled substance under the Controlled Substances Act.[1]

The approved or historically recognized medical uses have included hereditary angioedema and selected wasting or catabolic conditions. Its clinical use has contracted because safer alternatives, including C1 esterase inhibitor products and other targeted therapies for hereditary angioedema, have gained adoption.

The current market has four segments:

Segment	Market condition	Commercial outlook
U.S. approved human pharmaceutical use	Small and intermittent	Stable to declining
International human pharmaceutical use	Fragmented by country	Dependent on local registration and supply
Veterinary use	Present in selected markets	Limited by regulation and substitution
Illicit performance-enhancing use	Material but unregulated	Financially significant but not legitimate pharmaceutical revenue

Stanozolol is not a growth product in mainstream pharmaceutical markets. Demand is constrained by controlled-substance rules, adverse-effect concerns, competition from newer therapies, and reputational risk associated with anabolic-steroid misuse.

How large is the stanozolol market?

No reliable public source reports global stanozolol revenue as a standalone pharmaceutical category. Commercial market reports that aggregate anabolic steroids, performance-enhancing drugs, or veterinary steroids should not be treated as stanozolol-specific revenue estimates.

The legitimate market is likely small relative to major branded medicines because:

Stanozolol is an old small-molecule product with generic competition.
The original branded franchise has largely disappeared from major pharmaceutical-company reporting.
Few manufacturers have an economic incentive to maintain broad distribution.
Physician demand is concentrated in narrow indications.
Controlled-substance compliance raises operating costs without creating meaningful pricing power.

Retail prices can vary substantially by country, dosage form, manufacturer, pharmacy channel, and supply status. Price changes therefore do not provide a reliable proxy for market expansion. A temporary shortage can increase transaction prices while total unit demand remains unchanged.

Where is the revenue concentrated?

Revenue is likely concentrated among private or specialty manufacturers rather than large multinational pharmaceutical companies. Generic products may be sold through wholesalers, hospital pharmacies, specialty pharmacies, compounding channels, or local distributors. Manufacturer-level revenue is generally not disclosed in annual reports.

The illicit market cannot be included in pharmaceutical revenue estimates. It has no consistent product-quality controls, no dependable transaction records, and frequently involves counterfeit or misbranded products. FDA has repeatedly warned that unapproved bodybuilding products may contain anabolic steroids or steroid-like substances and may create serious safety risks.[2]

When does stanozolol lose exclusivity?

Stanozolol lost meaningful U.S. patent exclusivity decades ago. The active ingredient and core oral and injectable dosage technologies are not protected by a current branded patent estate that would prevent generic competition.

Exclusivity category	Current position
Original compound patent	Expired
Original formulation protection	Expired or commercially irrelevant
U.S. new chemical entity exclusivity	Expired
Current U.S. pediatric exclusivity	None identified
Current orphan exclusivity	None identified for stanozolol
Current branded market exclusivity	None of practical importance
Generic competition	Permitted, subject to FDA approval and controlled-substance requirements

The relevant commercial issue is not the date of a single patent expiration. It is that stanozolol has been available as an old generic product for many years. Any remaining patent rights would need to cover a specific new formulation, manufacturing process, combination, or delivery system rather than the established active ingredient itself.

What is the Orange Book status of stanozolol?

The U.S. Orange Book is the key source for approved drug products, therapeutic-equivalence evaluations, patents, and exclusivity information.[3] Stanozolol does not have a commercially significant active Orange Book patent listing that creates a barrier to ordinary generic entry.

The historical Winstrol product was an older branded product, and FDA records identify discontinued versions and legacy approvals. The practical market position is that generic applicants do not face a current branded patent wall comparable to those protecting high-value specialty medicines.

An Orange Book review should distinguish among:

a product listed as discontinued;
an approval that remains legally active but has limited distribution;
a patent listing that has expired;
a product with no current commercial supply;
a generic application that is approved but not actively marketed.

These distinctions matter because nominal approval does not guarantee commercial availability.

How strong is the patent estate for stanozolol?

The patent estate is weak from a blocking-rights perspective and stronger only in narrow technical areas.

Active ingredient and composition patents

The active ingredient is old and widely described in the pharmaceutical literature. Composition-of-matter protection has no current value in the United States or other mature generic markets.

Formulation patents

A manufacturer could seek protection for a novel formulation, such as:

modified-release oral delivery;
a depot injectable formulation;
a transdermal system;
a combination product;
a stability-enhanced formulation;
a specialized veterinary delivery system.

Such rights would protect only the claimed formulation. They would not prevent competitors from selling conventional immediate-release tablets or other non-infringing presentations.

Method-of-use patents

Method-of-use protection could theoretically cover a defined disease, patient population, dosing regimen, or treatment protocol. Its commercial value would be limited because stanozolol has a narrow and declining clinical market. Enforcement would also be difficult where prescriptions are written for broader or off-label uses.

Manufacturing and process protection

Manufacturing know-how may be more important than patents. Controlled-substance handling, impurity control, steroid synthesis, analytical testing, and regulatory documentation can create practical barriers. These are supply and compliance barriers, not durable monopoly rights.

Which companies are challenging stanozolol exclusivity?

No major current Paragraph IV litigation campaign is associated with stanozolol comparable to litigation around high-revenue branded drugs. Generic entry occurred long ago, and the product is already a mature generic.

A Paragraph IV certification is relevant only when a listed patent remains in the Orange Book. For stanozolol, the commercial question is generally whether an applicant can obtain or maintain an abbreviated new drug application, not whether it can defeat a current blockbuster patent.

Potential competitive pressure comes from:

generic tablet manufacturers;
specialty and hospital suppliers;
compounders operating within applicable law;
international manufacturers;
veterinary-drug suppliers;
illicit producers, which compete outside the regulated market.

The principal regulatory risk for legitimate suppliers is not patent litigation. It is loss of manufacturing capacity, controlled-substance compliance failure, quality defects, or inability to justify continued commercial distribution.

What FDA regulatory status affects stanozolol sales?

FDA status affects supply reliability more than market exclusivity.

A legitimate U.S. supplier must address:

an approved drug application or lawful compounding pathway;
current good manufacturing practice requirements;
controlled-substance registration and recordkeeping;
prescription-only distribution;
labeling and pharmacovigilance obligations;
import and supply-chain controls;
product quality and sterility requirements for injectables.

FDA’s Drugs@FDA and Orange Book databases are the primary sources for verifying approval history, marketing status, therapeutic equivalence, patents, and exclusivity.[3][4]

Stanozolol’s regulatory burden is high relative to its revenue potential. A manufacturer may face fixed compliance costs similar to those for more valuable products while earning only limited volume-based revenue. That economics can cause intermittent supply, product discontinuation, or reliance on a small number of suppliers.

Is there biosimilar risk for stanozolol?

No. Stanozolol is a chemically synthesized small molecule, not a biologic. Biosimilar regulation under the Public Health Service Act does not apply.

The relevant competitive risks are generic substitution, therapeutic substitution, and non-approved supply. Therapeutic substitution is especially important in hereditary angioedema, where modern targeted treatments can reduce the clinical role of older anabolic-steroid therapy.

What patent litigation and settlement agreements affect stanozolol?

No material, ongoing U.S. patent litigation or settlement agreement is publicly associated with the mature stanozolol market at the level expected for a high-value branded medicine.

The absence of litigation reflects the product’s age and low commercial value. Generic manufacturers have little reason to litigate over an expired core patent estate, while branded companies have limited economic incentive to defend a declining franchise.

International disputes may arise over manufacturing, trademarks, counterfeit products, or local regulatory approvals. Those matters should not be confused with a U.S. patent-based market-exclusion strategy.

How does stanozolol compare with competing drugs?

Product or class	Primary commercial role	Competitive effect on stanozolol
C1 esterase inhibitor products	Hereditary angioedema prevention or treatment	Strong clinical substitution
Lanadelumab	Long-term hereditary angioedema prevention	Strong substitution in eligible patients
Berotralstat	Oral hereditary angioedema prevention	Competes on convenience and targeted therapy
Danazol	Older androgenic therapy	Closest legacy therapeutic comparator
Testosterone products	Hormone replacement and anabolic indications	Competes in broader steroid-related demand
Other anabolic steroids	Performance-enhancing and specialty uses	Competes in illicit and veterinary channels

Stanozolol’s main disadvantage is not necessarily price. It is the combination of limited indications, safety monitoring, controlled-substance status, and availability of more targeted therapies.

What generic launch risks exist for stanozolol?

Generic launch is legally feasible but commercially difficult.

Regulatory and manufacturing risks

A potential entrant must manage active-pharmaceutical-ingredient qualification, tablet or injectable manufacturing, stability data, bioequivalence, labeling, controlled-substance registration, and post-market quality systems.

Injectable products carry higher manufacturing and recall risk because sterility failures can create substantial liability. Oral products are operationally simpler but may face low pricing and limited pharmacy demand.

Commercial risks

The principal launch risks are:

insufficient annual volume;
wholesaler reluctance to stock a controlled anabolic steroid;
price erosion from multiple suppliers;
inconsistent API availability;
reputational exposure;
limited reimbursement;
demand concentrated in a small number of prescribers and patients.

A generic entrant would likely pursue a supply-led strategy rather than a high-price strategy. The product may be profitable as part of an existing controlled-substance portfolio, but unattractive as a standalone launch.

What is the financial trajectory for stanozolol?

Stanozolol’s legitimate pharmaceutical revenue trajectory has three phases.

Branded growth and maturity

The original Winstrol franchise benefited from historical use in anabolic, wasting, and hereditary angioedema indications. Revenue was supported by brand recognition and limited early competition.

Generic erosion

Once generic supply became available, price and market share shifted toward lower-cost products. The branded franchise lost strategic value, and stanozolol stopped appearing as a material line item for major pharmaceutical companies.

Fragmented maintenance market

The current market is a maintenance business. Revenue depends on a small prescription base, sporadic product availability, international sales, and specialty distribution. Growth is unlikely without a new formulation, a validated clinical use, or a major change in treatment guidelines.

The financial profile can be summarized as follows:

Metric	Assessment
Revenue growth	Flat to declining in legitimate markets
Gross margin	Potentially acceptable for efficient generic supply
Pricing power	Low
Volume visibility	Low
Patent protection	Negligible
Regulatory burden	High relative to product value
Litigation exposure	Low for patent disputes
Supply-chain risk	Moderate to high
Strategic value	Niche portfolio product
Upside case	Novel formulation or specialty indication
Downside case	Supplier exit and further therapeutic substitution

What licensing deals could change the market?

No major current licensing transaction is publicly associated with stanozolol. A licensing deal would make economic sense only if it added a defensible asset, such as a differentiated delivery system, a new indication, geographic registration rights, or a reliable regulated supply chain.

A simple transfer of legacy stanozolol rights would have limited value because the core molecule is generic and the market is small. The stronger transaction structures would involve:

regional commercialization rights;
manufacturing and API supply agreements;
veterinary distribution;
specialty pharmacy access;
a new formulation with separate intellectual-property protection.

What geographic markets offer the strongest opportunity?

The United States offers regulatory credibility but limited growth. Europe and other developed markets have similar pressure from generic substitution and safety controls. Emerging markets may have greater unit demand, but pricing, registration, counterfeit risk, and enforcement vary considerably.

The best commercial opportunities are likely to be niche and regional rather than global:

markets with established legal human or veterinary use;
jurisdictions with registered local products;
specialty distributors with controlled-substance capabilities;
countries where supply continuity is more important than premium pricing.

International sales must account for national controlled-substance laws, import permits, anti-doping restrictions, and local pharmacovigilance rules. Stanozolol is prohibited in sport under the World Anti-Doping Agency list, which limits legitimate athlete-related use and increases compliance risk.[5]

Key Takeaways

Stanozolol is a mature generic anabolic steroid with no meaningful remaining core patent exclusivity.
The legitimate pharmaceutical market is small, fragmented, and generally flat to declining.
No reliable public source reports standalone global stanozolol revenue.
U.S. commercial activity is constrained by Schedule III controls, FDA requirements, and limited medical demand.
Modern hereditary angioedema therapies have reduced the product’s therapeutic relevance.
Biosimilar risk is not applicable because stanozolol is a small molecule.
Patent litigation and Paragraph IV activity are not material current market drivers.
Formulation, manufacturing, and regional regulatory rights could create niche value, but the base molecule has limited strategic upside.
The strongest risks are supplier withdrawal, quality failures, price erosion, and therapeutic substitution.
Illicit demand may be substantial but should not be counted as regulated pharmaceutical revenue.

FAQs

Is stanozolol still sold by pharmaceutical companies?

Yes, stanozolol may remain available through selected generic, specialty, veterinary, or international suppliers, but availability is fragmented and can be intermittent. Major pharmaceutical companies generally do not report it as a material product.

Is Winstrol still a commercially important brand?

No. Winstrol has historical recognition, but it does not have the commercial position of a major active branded medicine. Current legitimate supply is primarily associated with generic or regional channels.

Can a company patent a new stanozolol product?

A company may seek patents for a novel formulation, delivery system, manufacturing process, combination, or method of use. It cannot recreate meaningful composition-of-matter exclusivity for the old active ingredient.

Is stanozolol profitable for generic manufacturers?

It can be profitable for a manufacturer with existing controlled-substance infrastructure, efficient production, and reliable distribution. As a standalone launch, the product has limited attractiveness because demand is small and pricing power is weak.

Does stanozolol have a future in hereditary angioedema treatment?

Its role is likely to remain limited. Newer targeted therapies have reduced reliance on older androgenic treatments, although access, cost, and local treatment guidelines can preserve some residual demand.

References

U.S. Drug Enforcement Administration. (2024). Controlled substances act: Schedule III controlled substances. https://www.deadiversion.usdoj.gov
U.S. Food and Drug Administration. (2023). Caution: Bodybuilding products can be risky. https://www.fda.gov
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th edition. https://www.fda.gov
U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
World Anti-Doping Agency. (2024). 2024 prohibited list. https://www.wada-ama.org

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	1
Drug Master File Entries:	2
Raw Ingredient (Bulk) Api Vendors:	53
Clinical Trials:	1
DailyMed Link:	stanozolol at DailyMed

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