ESTROGEL Drug Patent Profile

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Which patents cover Estrogel, and when can generic versions of Estrogel launch?

Estrogel is a drug marketed by Ascend Theraps Us and is included in one NDA.

The generic ingredient in ESTROGEL is estradiol. There is one drug master file entry for this compound. Forty-seven suppliers are listed for this compound. Additional details are available on the estradiol profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Estrogel

A generic version of ESTROGEL was approved as estradiol by BARR LABS INC on October 22^nd, 1997.

Summary for ESTROGEL

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	94
Clinical Trials:	8
Patent Applications:	4,044
Drug Sales Revenues:	Drug sales revenues for ESTROGEL
What excipients (inactive ingredients) are in ESTROGEL?	ESTROGEL excipients list
DailyMed Link:	ESTROGEL at DailyMed

See drug sales revenues for ESTROGEL

Recent Clinical Trials for ESTROGEL

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
University of Jyvaskyla	PHASE2
Tampere University Hospital	PHASE2
Central Finland Hospital District	PHASE2

See all ESTROGEL clinical trials

Pharmacology for ESTROGEL

Drug Class	Estrogen
Mechanism of Action	Estrogen Receptor Agonists

US Patents and Regulatory Information for ESTROGEL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Ascend Theraps Us	ESTROGEL	estradiol	GEL, METERED;TRANSDERMAL	021166-002	Feb 9, 2004	AB	RX	Yes	Yes
Ascend Theraps Us	ESTROGEL	estradiol	GEL;TOPICAL	021166-001	Feb 9, 2004		DISCN	No	No

EstroGel Market Dynamics, Financial Trajectory, Patents, and Generic Competition

Last updated: October 26, 2026

EstroGel is a prescription transdermal estradiol gel marketed in the United States by Ascend Therapeutics. Its commercial position depends on menopausal hormone therapy demand, pharmacy coverage, generic estradiol gel competition, and the broader shift toward lower-dose and localized estrogen products. EstroGel has no publicly reported standalone revenue, and Ascend is privately held. Public data therefore support market and competitive analysis, but not a verified product-level revenue series.

What is EstroGel and how does it work?

EstroGel is a transdermal gel containing 0.06% estradiol. The product is applied to the skin and delivers systemic estrogen without oral first-pass hepatic exposure. One pump actuation delivers 1.25 grams of gel containing 0.75 mg of estradiol; the usual starting dose is one pump daily, subject to clinical adjustment. (FDA, 2023a)

The FDA-approved label covers treatment of moderate-to-severe vasomotor symptoms and vulvar and vaginal atrophy associated with menopause. Estrogen-alone therapy is indicated for women without a uterus. Women with an intact uterus generally require a progestogen to reduce endometrial hyperplasia risk. (FDA, 2023a)

EstroGel product profile

Attribute	EstroGel profile
Active ingredient	Estradiol
Dosage form	Transdermal gel
Strength	0.06%
Standard pump delivery	1.25 g gel, 0.75 mg estradiol
Route	Topical, systemic transdermal absorption
FDA application	NDA 021166
Primary use	Menopausal vasomotor symptoms and vulvar/vaginal atrophy
U.S. marketer	Ascend Therapeutics
Product type	Prescription drug
Regulatory category	Nonbiologic small-molecule hormone therapy

What is the FDA status of EstroGel?

EstroGel was approved by the FDA in 2004 under NDA 021166. The product remains an approved prescription estrogen therapy, subject to the class labeling requirements applicable to systemic estrogen products. Those warnings address cardiovascular events, stroke, venous thromboembolism, breast cancer, probable dementia in certain older populations, and endometrial cancer risk when estrogen is used without adequate progestogen protection. (FDA, 2023a)

The FDA label has a direct commercial effect. EstroGel is not positioned as an unrestricted wellness product. Prescribers and payers evaluate duration, dose, contraindications, age, route of administration, and whether a local vaginal product could address the patient’s symptoms with lower systemic exposure.

How does EstroGel compare with oral estradiol?

Factor	EstroGel	Oral estradiol
Administration	Daily skin application	Daily tablet
Hepatic first-pass exposure	Avoided	Present
Dose flexibility	Gel dose can be adjusted within label parameters	Fixed tablet strengths
Adherence risk	Application technique and skin transfer	Tablet adherence
Commercial position	Transdermal premium or branded generic segment	Larger, more commoditized tablet market
Competitive alternatives	Patches, sprays, emulsions, compounded gels	Generic estradiol tablets

Transdermal delivery is an important demand driver because some prescribers prefer it for patients with elevated thrombotic or metabolic concerns. The product remains exposed to competition from estradiol patches, sprays, pumps, compounded preparations, and generic gels.

How large is the EstroGel market?

The addressable market is the U.S. systemic menopausal hormone therapy market rather than the EstroGel product alone. EstroGel competes within a category that includes:

• Generic oral estradiol.
• Estradiol transdermal patches.
• Estradiol topical emulsions, sprays, and gels.
• Conjugated estrogens.
• Combination estrogen-progestin products.
• Vaginal estrogen creams, tablets, rings, and inserts.
• Compounded hormone replacement therapies.

Demand is supported by the large postmenopausal population and renewed clinical interest in individualized hormone therapy. Product selection is constrained by safety labeling, symptom type, age at initiation, time since menopause, route of administration, and insurance coverage.

The market is fragmented. Oral estradiol and transdermal patches generally have greater prescription volume than branded estrogen gels because they have broader generic availability and lower out-of-pocket cost. EstroGel can retain value among patients who prefer gel delivery or who do not tolerate patches.

What market forces affect EstroGel sales?

Market force	Effect on EstroGel
Generic estradiol availability	Reduces pricing power and payer preference
Preference for transdermal estrogen	Supports demand
Insurance formulary controls	Can shift prescriptions to patches or lower-cost gels
Menopause treatment awareness	Expands diagnosis and treatment consideration
Safety concerns about systemic estrogen	Limits duration and eligible population
Local vaginal estrogen growth	Diverts some atrophy-related demand
Compounded hormone therapy	Creates lower-cost but less standardized competition
Supply reliability	Can improve substitution opportunities when alternatives are unavailable
Brand recognition	Supports retention in a mature category but does not prevent generic substitution

What is EstroGel’s financial trajectory?

EstroGel does not have a publicly reported standalone revenue history. Ascend Therapeutics is privately held, and its public disclosures do not provide audited EstroGel sales, operating margin, prescription volume, or product-level cash flow. Perrigo’s historical public filings and other large-company disclosures do not establish a reliable current EstroGel revenue series. (Perrigo, 2023)

The financial trajectory is therefore best characterized by product maturity rather than reported revenue growth:

1. The product moved from protected branded commercialization into a mature systemic estrogen market.
2. Generic estradiol gel availability increased price and formulary pressure.
3. Prescription value shifted from patent exclusivity to brand retention, distribution, manufacturing reliability, and payer access.
4. Revenue growth is likely constrained unless the marketer gains share through supply continuity, contracting, or expanded prescriber adoption.
5. Gross margin is likely higher than for many commodity oral generics but lower than for a fully protected branded product because the underlying active ingredient is well established and multiple delivery formats compete.

Does EstroGel generate material revenue for its marketer?

Public sources do not establish a verified dollar figure. Ascend’s private ownership structure prevents the type of product-level disclosure available for publicly traded pharmaceutical companies. The commercial asset may still be strategically valuable because a mature transdermal product can generate recurring prescription revenue with lower clinical-development risk than a new drug.

The principal valuation variables are net price, refill persistence, payer mix, generic substitution, manufacturing cost, pharmacy distribution, and the number of competing estradiol products. Prescription volume alone would not establish profitability.

What patents protect EstroGel?

EstroGel’s commercial protection is not equivalent to that of a newly launched chemical entity. Estradiol is an established active ingredient, and the relevant intellectual-property value has historically depended on formulation, delivery system, manufacturing, and regulatory exclusivity rather than novel molecular composition.

The FDA Orange Book is the primary source for patents and exclusivity associated with approved drug products. Orange Book records must be evaluated by NDA and product presentation because listed patents can change through updates, delistings, and patent-expiration events. (FDA, 2024)

What formulations are protected by EstroGel patents?

Potentially relevant protection categories include:

• Gel composition and excipient systems.
• Estradiol concentration and delivery characteristics.
• Metered-dose pump architecture.
• Skin-penetration and absorption performance.
• Manufacturing and filling processes.
• Packaging designed to control dose delivery.
• Method-of-use claims for menopausal symptoms.

These categories do not automatically create enforceable market exclusivity. A generic applicant can challenge listed patents, design around claim limitations, or rely on an expired patent landscape.

No current, publicly verified patent portfolio supports treating EstroGel as a product with broad, long-duration exclusivity comparable to a recently launched specialty drug.

When does EstroGel lose exclusivity?

EstroGel’s principal exclusivity risk has already shifted from future patent expiry to generic substitution and market commoditization. The key U.S. commercial event was FDA approval of generic estradiol gel products, including generic competition associated with Perrigo. FDA product databases and the Orange Book should be used to confirm current approved manufacturers and active listings. (FDA, 2024; FDA, 2023b)

Because EstroGel contains an established hormone and has been marketed for many years, its practical exclusivity is determined by:

• Active Orange Book patent listings.
• The availability of approved generic estradiol gel.
• State substitution rules.
• Payer formulary placement.
• Any authorized-generic arrangement.
• Supply disruptions affecting competing products.

EstroGel exclusivity timeline

Period	Commercial event
2004	FDA approval of EstroGel under NDA 021166
Mature-market period	Expansion of competing estradiol products and alternative routes
Generic-entry period	FDA approval of generic estradiol gel products
Current phase	Brand retention and payer competition rather than molecule-level exclusivity

Are there Paragraph IV challenges to EstroGel?

A Paragraph IV certification is relevant only when an abbreviated new drug application references a listed drug patent and asserts that the patent is invalid, unenforceable, or will not be infringed. FDA approval of a generic does not by itself prove that a Paragraph IV lawsuit occurred.

Public FDA records do not provide a complete litigation database. No major, publicly established EstroGel Paragraph IV settlement is a central current market event in the available public record. The commercial effect of generic entry is more important than litigation history because the market already contains competing estradiol gel products.

What patent litigation and settlement agreements affect EstroGel?

No widely reported active patent litigation materially changes EstroGel’s current U.S. competitive position in the available public record. The product’s main risk is substitution by approved generic estradiol products, not an unresolved high-value patent dispute.

Any acquisition, licensing, or settlement agreement involving EstroGel would need to be confirmed through SEC filings, court dockets, FDA records, or transaction announcements. Ascend’s private status limits visibility into licensing economics, royalty rates, milestone payments, and transfer pricing.

Which companies compete with EstroGel?

The competitive set includes branded and generic manufacturers across multiple delivery systems.

Competitor group	Examples	Competitive effect
Generic estradiol gel	FDA-approved generic manufacturers	Direct substitution and price pressure
Estradiol patches	Mylan/Viatris, Sandoz, other generic suppliers	Strong transdermal alternative
Oral estradiol	Multiple generic manufacturers	Lower-cost systemic alternative
Estradiol spray	Evamist and related products	Competes for patients preferring topical dosing
Estradiol emulsions	Divigel and generic or authorized-generic alternatives	Similar route with different packaging and dosing
Vaginal estrogen products	Creams, tablets, rings, inserts	Divert atrophy-focused prescribing
Compounded hormone therapy	Compounding pharmacies	Price and customization competition, with different regulatory oversight

The most direct competition comes from generic estradiol gel and other transdermal products. Vaginal estrogen is a narrower but important substitute when the treatment objective is genitourinary symptoms rather than systemic vasomotor control.

What generic launch scenarios exist for EstroGel?

Scenario 1: Stable branded niche

EstroGel retains a patient segment that values gel administration, maintains acceptable payer coverage, and benefits from limited generic supply. Revenue remains stable but pricing gradually erodes.

Scenario 2: Accelerated substitution

Payers place generic estradiol gel and patches on preferred tiers. Pharmacies substitute automatically where permitted. EstroGel prescription volume and net price decline.

Scenario 3: Transdermal category expansion

Greater acceptance of transdermal estrogen expands the category. EstroGel gains prescriptions, but much of the incremental volume flows to lower-cost patches and generic gels.

Scenario 4: Supply-driven share gain

Shortages or manufacturing interruptions affecting patches or competing gels allow EstroGel to gain temporary share. The benefit is unlikely to persist after supply normalizes.

How strong is the EstroGel patent estate?

EstroGel’s patent estate is commercially moderate to weak compared with a newly approved drug because the active ingredient is old, generic alternatives exist, and the main differentiation is delivery technology. Formulation and device claims can delay or complicate generic entry, but they generally do not create durable protection when competing products have alternative formulations or routes.

The most defensible value lies in:

• Regulatory approval and established labeling.
• Prescriber familiarity.
• Patient persistence.
• Manufacturing know-how.
• Pump and packaging performance.
• Distribution relationships.
• Brand or marketer continuity.

Manufacturing barriers are meaningful only if they affect reproducible dosing, gel homogeneity, pump accuracy, skin absorption, stability, or packaging. They are less valuable when a generic can demonstrate bioequivalence or therapeutic equivalence through an alternative presentation.

Does EstroGel face biosimilar risk?

No. EstroGel is a nonbiologic estradiol product, so biosimilar regulation does not apply. Its competitive threat comes from abbreviated new drug applications, generic substitution, therapeutic alternatives, and compounded products rather than biosimilars.

What is EstroGel’s geographic coverage?

EstroGel’s principal commercial importance is in the United States, where it is approved under NDA 021166 and distributed through the U.S. prescription market. International estradiol gel products may use different names, sponsors, formulations, strengths, and regulatory pathways. U.S. patent, exclusivity, pricing, and litigation conclusions should not be transferred to Canada, Europe, or other markets without country-specific review.

Key Takeaways

• EstroGel is a mature transdermal estradiol product marketed in the United States by Ascend Therapeutics.
• Its FDA application is NDA 021166, and its formulation is 0.06% estradiol gel.
• No verified standalone revenue series is publicly available because Ascend is privately held.
• The financial trajectory is driven by generic substitution, payer coverage, refill persistence, and transdermal estrogen demand.
• Generic estradiol gel and estradiol patches are the most direct competitive threats.
• EstroGel has no biosimilar risk because estradiol gel is a nonbiologic small-molecule product.
• Current commercial protection rests more on brand, supply, manufacturing, and distribution than on durable molecule-level patent exclusivity.
• No major publicly established Paragraph IV settlement or active patent dispute materially changes the current market outlook.

FAQs

Is EstroGel still commercially protected by patents?

EstroGel is not protected by the type of broad new-molecule exclusivity associated with a recent drug launch. Any remaining protection depends on current Orange Book listings, formulation claims, device claims, and manufacturing rights.

Is generic EstroGel available?

Generic estradiol gel products have received FDA approval, creating direct competition with branded EstroGel. Availability and substitution depend on the manufacturer, pharmacy inventory, payer formularies, and state law.

Is EstroGel more expensive than estradiol patches?

Usually, branded EstroGel faces greater price pressure than generic estradiol patches or tablets. Patient cost depends on insurance coverage, deductibles, formulary tier, and pharmacy pricing.

Can EstroGel revenue grow despite generic competition?

Yes, but growth would most likely come from increased transdermal estrogen use, improved payer access, supply advantages, or higher refill persistence rather than from patent-protected price increases.

Who owns the EstroGel brand?

The U.S. product is marketed by Ascend Therapeutics. Ownership, licensing, and royalty economics should be distinguished because the marketer, regulatory sponsor, manufacturer, and intellectual-property owner may not be the same entity.

References

1. U.S. Food and Drug Administration. (2023a). EstroGel (estradiol gel) prescribing information, NDA 021166.
2. U.S. Food and Drug Administration. (2023b). Drugs@FDA: FDA-approved drug products and abbreviated new drug applications.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book.
4. Perrigo Company plc. (2023). Annual report for fiscal year 2023.