Last updated: July 31, 2026
Danazol is an established generic androgenic steroid with no active branded exclusivity, no meaningful patent barrier, and limited current clinical-development activity. Its commercial use is concentrated in hereditary angioedema, endometriosis and selected off-label hematologic or gynecologic indications. Demand should remain stable to modestly declining through 2030, with supply continuity, safety monitoring and generic manufacturer participation driving the market more than innovation or patent protection.
What is the current FDA status of danazol?
Danazol is an FDA-approved oral synthetic androgen available in capsules. The historical branded product is Danocrine. U.S. generic products are marketed in 50 mg, 100 mg and 200 mg capsules, subject to manufacturer-specific availability.
| Regulatory item |
Status |
| Active ingredient |
Danazol |
| Dosage form |
Oral capsule |
| FDA approval history |
Original approval in the 1970s |
| Historical reference brand |
Danocrine |
| Common strengths |
50 mg, 100 mg, 200 mg |
| U.S. prescription status |
Prescription only |
| Primary approved uses |
Endometriosis, fibrocystic breast disease, hereditary angioedema |
| Current innovation pathway |
Generic-drug market |
| Biologic status |
Not applicable |
| FDA exclusivity |
Expired |
| U.S. regulatory risk |
Product availability, labeling, safety and manufacturing continuity |
Danazol suppresses pituitary gonadotropin secretion and has weak androgenic and anabolic activity. In hereditary angioedema, it increases hepatic production of C1 esterase inhibitor and can reduce attack frequency. In endometriosis, it suppresses ovarian steroidogenesis and produces a hypoestrogenic environment.[1][2]
The principal safety limitations are weight gain, acne, hirsutism, voice changes, menstrual disruption, adverse lipid effects, hepatotoxicity and fetal virilization. The FDA label advises against use during pregnancy and recommends liver-function monitoring during treatment.[1]
What clinical trials are studying danazol?
The current danazol clinical-trial landscape is small and predominantly investigator-led. Danazol does not have an active late-stage program comparable with modern hereditary-angioedema products such as lanadelumab, berotralstat, garadacimab or plasma-derived C1-inhibitor products.
Clinical-trial activity by indication
| Indication |
Current development position |
Commercial relevance |
| Hereditary angioedema |
Historical evidence and guideline-supported use; limited new interventional development |
Residual demand where cost or access favors oral generic therapy |
| Endometriosis |
Historical randomized studies; no major current registration program |
Declining use because of tolerability and newer hormonal options |
| Fibrocystic breast disease |
Historical approved indication; limited contemporary trial activity |
Low |
| Immune thrombocytopenia and other hematologic disorders |
Off-label, case-series and small-study use |
Niche and specialist-dependent |
| Myelofibrosis or marrow-failure syndromes |
Historical or exploratory androgen use, generally not a danazol growth market |
Limited |
| Emerging anti-aging or performance uses |
No accepted FDA development pathway |
Not a regulated growth segment |
ClinicalTrials.gov remains the principal U.S. registry for identifying active and completed danazol studies. Registry records include older studies and studies in which danazol is a comparator, background therapy or investigational treatment. The presence of a registry record does not indicate an active commercial development program.[3]
No current evidence supports a new-drug application, priority review, breakthrough designation or pivotal trial program for danazol. Its development profile is therefore best described as mature, generic and indication-specific.
What are the most important recent clinical developments?
The major clinical change is substitution, not innovation. For hereditary angioedema, modern prophylactic therapies have reduced reliance on danazol because they avoid the androgenic adverse-effect burden.
Guidelines continue to place attenuated androgens such as danazol among effective prophylactic options, particularly where newer treatments are unavailable or unaffordable. They are generally not preferred when safer long-term alternatives exist.[4]
For endometriosis, danazol has largely been displaced by combined hormonal contraceptives, progestins, gonadotropin-releasing hormone antagonists and other hormonal strategies. Its adverse-effect profile limits chronic use. Contemporary trials are focused on newer mechanisms rather than reformulating or repositioning danazol.
When does danazol lose exclusivity?
Danazol lost meaningful U.S. market exclusivity decades ago. The product is a small-molecule generic, not a biologic, and it does not have biosimilar exclusivity issues.
| Exclusivity category |
Danazol position |
| New chemical entity exclusivity |
Expired |
| Orphan-drug exclusivity |
No current relevant exclusivity identified |
| Pediatric exclusivity |
Expired or not commercially relevant |
| Patent term extension |
No current commercial significance |
| Generic approval pathway |
Abbreviated New Drug Application |
| Biosimilar competition |
Not applicable |
The commercial market is governed by abbreviated generic approvals, manufacturing capacity, regulatory compliance and wholesaler contracting. New entrants may face formulation, bioequivalence and supply-chain requirements, but not an effective blocking patent estate.
What patents protect danazol and its formulations?
No active, commercially meaningful patent barrier is expected to prevent generic danazol sales in the United States. The original compound, basic oral capsule technology and historical therapeutic-use claims are long past ordinary patent terms.
Patent-estate assessment
| Patent category |
Current risk |
| Compound patent |
Expired |
| Salt or polymorph patent |
No material blocking estate identified |
| Immediate-release capsule patent |
Expired or commercially irrelevant |
| Endometriosis method-of-use patent |
Expired |
| Hereditary-angioedema method-of-use patent |
Expired or not blocking generic entry |
| Manufacturing patent |
Potentially relevant to individual suppliers, not a market-wide barrier |
| Device or delivery-system patent |
Not material for current oral capsules |
The remaining intellectual-property risk is operational. A manufacturer could hold confidential process know-how, supplier contracts, analytical methods or regulatory documentation. Those assets may affect production economics but do not create branded exclusivity.
What is the Orange Book status of danazol?
Danazol is associated historically with the Danocrine reference product and generic capsule approvals. Current Orange Book analysis should distinguish between an approved product, a marketed product and a product listed as discontinued. A discontinued branded product may remain relevant as the reference product for generic approval history without representing an active commercial brand.
The expected Orange Book position is:
- No active patent listings that block ordinary generic danazol entry.
- No current three-year or five-year exclusivity of commercial significance.
- Generic approvals based on bioequivalence to the reference product.
- Manufacturer-specific marketing status that may change as suppliers enter or leave the market.[5]
Paragraph IV litigation is therefore unlikely to be a central issue. A new generic applicant would generally face more practical risk from approval timing, product availability, quality compliance and market size than from challenging an unexpired danazol patent.
Which companies are challenging danazol exclusivity?
No significant current Paragraph IV challenger landscape is associated with danazol. The market is already genericized, and competition is primarily among existing or potential ANDA holders.
The relevant competitive groups are:
- Generic capsule manufacturers with approved U.S. ANDAs.
- Contract manufacturers supplying national or regional distributors.
- International manufacturers selling danazol in markets with local approvals.
- Specialty distributors serving hereditary-angioedema patients.
- Manufacturers of newer hereditary-angioedema therapies competing clinically rather than through patent litigation.
Company-level market shares are difficult to interpret because danazol may be supplied through multiple labelers, wholesalers and contract manufacturing arrangements. A labeler’s product listing does not necessarily equal a dedicated manufacturing facility or a significant share of prescriptions.
What patent litigation and settlement agreements affect danazol?
No major active U.S. patent litigation or settlement agreement is central to the current danazol market. The absence of litigation reflects the age of the product and the lack of a commercially valuable unexpired patent estate.
Potential disputes are more likely to involve:
- ANDA product quality or bioequivalence;
- manufacturing-site compliance;
- recalls or supply interruptions;
- trademark or labeling issues;
- state reimbursement and pharmacy contracting.
These matters can affect a supplier’s market position without changing the competitive structure of the active ingredient.
How strong is the danazol patent estate?
The danazol patent estate is weak for exclusivity purposes and moderate only as an operational barrier.
| Strength factor |
Assessment |
| Core molecule protection |
None of current commercial value |
| Formulation protection |
Low |
| Method-of-use protection |
Low |
| Manufacturing know-how |
Potentially moderate for individual suppliers |
| Regulatory barrier |
Low to moderate |
| Switching barrier |
Low for many indications; higher in stable HAE patients |
| Generic entry risk |
High |
| Brand pricing power |
Minimal |
The strongest practical barrier is physician and patient reluctance to switch a stable hereditary-angioedema regimen, especially where a patient has responded to danazol and newer products are expensive. That barrier is clinical and reimbursement-based, not patent-based.
How does danazol compare with newer hereditary-angioedema drugs?
Danazol competes mainly on acquisition cost and historical familiarity. Newer products compete on safety, convenience, mechanism and prophylactic efficacy.
| Product class |
Route |
Main advantage over danazol |
Main limitation |
| Danazol |
Oral capsule |
Low cost and oral administration |
Androgenic toxicity and monitoring |
| Lanadelumab |
Subcutaneous injection |
Long-acting prophylaxis and non-androgenic profile |
High cost and injection |
| Berotralstat |
Oral tablet |
Oral, targeted kallikrein inhibition |
Higher cost; drug-interaction considerations |
| C1-inhibitor products |
Intravenous or subcutaneous |
Replacement therapy with established use |
Administration burden and cost |
| Garadacimab |
Subcutaneous, jurisdiction-dependent |
Long-acting targeted prophylaxis |
Patent-protected branded competition and access constraints |
Danazol remains relevant in lower-resource settings and in treatment pathways where newer agents are unavailable. In higher-income markets, use is likely to contract as guidelines and payers favor non-androgenic prophylaxis.
What is the danazol market outlook through 2030?
Public company filings generally do not report danazol revenue separately. Market-research estimates for the global danazol market vary because they use different assumptions about prescription volume, international availability, hospital use and off-label demand. A precise global revenue figure cannot be treated as an audited industry metric.
Base-case projection
The base case is a low-growth or declining mature-generic market through 2030.
| Driver |
2025-2030 effect |
| Expired exclusivity |
Sustained price pressure |
| Newer HAE prophylaxis |
Reduced use in developed markets |
| Low-cost access |
Continued demand in price-sensitive markets |
| Endometriosis substitution |
Continued volume erosion |
| Generic supplier turnover |
Periodic supply volatility |
| Manufacturing concentration |
Potential short-term shortages |
| New clinical trials |
Unlikely to create material demand |
Scenario analysis
| Scenario |
Market outcome through 2030 |
Main assumptions |
| Downside |
Moderate volume and revenue decline |
Rapid conversion to modern HAE therapy and continued endometriosis substitution |
| Base case |
Stable to modest decline |
Persistent low-cost use, especially outside premium markets |
| Upside |
Temporary volume stabilization |
Supply shortages or reimbursement pressure increase use of low-cost prophylaxis |
Revenue exposure is concentrated in generic suppliers and distributors rather than an originator. Pricing power is limited, and a supplier’s value is tied to reliable production, regulatory compliance and access to active pharmaceutical ingredient sources.
What generic launch risks exist for danazol?
A new generic entrant would face low intellectual-property risk but meaningful commercial and operational risk.
Key launch risks
- The total addressable market is small relative to high-volume generic products.
- Several suppliers may compete for a limited prescription base.
- Price erosion can occur quickly after launch.
- FDA manufacturing observations or supply interruptions can create volatility.
- Hereditary-angioedema patients may not switch easily from a stable regimen.
- Newer products can displace demand even when danazol remains clinically effective.
- Endometriosis demand is structurally weaker than historical demand.
- Procurement contracts may favor established suppliers.
The strongest launch opportunity is a reliable, competitively priced product with uninterrupted supply. A novel formulation would need a clear tolerability, adherence or dosing advantage to support meaningful differentiation.
Where is danazol commercial demand strongest?
Demand is likely to persist in three geographic segments:
- Countries where hereditary-angioedema biologics and targeted small molecules are not reimbursed.
- Health systems that prioritize low acquisition cost over long-term androgenic safety.
- Markets with established specialist familiarity and local generic manufacturing.
North America and Western Europe have the greatest access to newer therapies and therefore the highest substitution risk. Emerging markets may retain danazol longer because price and availability determine treatment selection.
International status varies by national registration, reimbursement and supply. FDA approval does not establish automatic authorization in Europe, Asia-Pacific, Latin America or the Middle East.
What manufacturing and intellectual-property barriers affect danazol?
Danazol manufacturing is technically mature, but suppliers must maintain control over steroid synthesis, impurity profiles, analytical validation, capsule uniformity and dissolution performance. The relevant risks include:
- Active pharmaceutical ingredient availability;
- steroid-related impurity control;
- validated bioequivalence;
- content uniformity at low capsule strengths;
- supplier qualification;
- facility compliance;
- packaging and stability;
- recall management.
These factors can produce temporary shortages or supplier exits. They do not support durable premium pricing unless the market experiences a sustained supply disruption.
Key Takeaways
- Danazol is an old, FDA-approved generic oral androgen with no meaningful remaining market exclusivity.
- Current clinical activity is limited; no major commercial development program is evident.
- Hereditary angioedema is the most durable demand segment, but newer non-androgenic therapies are displacing use.
- Endometriosis and fibrocystic breast disease are no longer major growth indications.
- The patent estate is commercially weak, and Paragraph IV litigation is not a major market issue.
- Orange Book relevance is tied to reference-product and generic-approval history rather than active patent protection.
- Market revenue is not separately disclosed by most suppliers; a stable-to-declining outlook through 2030 is the most defensible base case.
- Generic supply reliability, manufacturing compliance and pricing will determine commercial performance.
FAQs About Danazol Clinical Trials and Market Forecasts
Is danazol still FDA approved?
Yes. Danazol remains an FDA-approved oral capsule for indications including endometriosis, fibrocystic breast disease and hereditary angioedema, subject to product-specific marketing status.[1][5]
Is danazol a biologic or a biosimilar?
No. Danazol is a synthetic small-molecule drug. Biosimilar regulation does not apply.
Can a generic company launch danazol without a patent challenge?
Ordinarily, yes, if the applicant satisfies the applicable ANDA requirements and no relevant unexpired patent or exclusivity blocks approval.
Why do some hereditary-angioedema patients still use danazol?
Low cost, oral administration, historical familiarity and limited access to newer therapies support continued use in selected patients.[4]
Does danazol have a meaningful reformulation opportunity?
The opportunity is limited. A reformulation would need to reduce androgenic toxicity, improve tolerability or materially simplify dosing while preserving efficacy. Without that differentiation, generic pricing and newer HAE therapies constrain commercial returns.
References
- U.S. Food and Drug Administration. (n.d.). Danazol prescribing information. FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/
- National Library of Medicine. (n.d.). Danazol. DailyMed. https://dailymed.nlm.nih.gov/dailymed/
- National Library of Medicine. (n.d.). ClinicalTrials.gov: Danazol studies. https://clinicaltrials.gov/search?term=danazol
- Maurer, M., Magerl, M., Betschel, S., et al. (2022). The international WAO/EAACI guideline for the management of hereditary angioedema. Allergy, 77(7), 1961-1990. https://doi.org/10.1111/all.15214
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
