When do the patents on MICRONOR expire, and when will MICRONOR go generic?

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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
Janssen Pharms	MICRONOR	norethindrone	TABLET;ORAL-28	016954-001	Approved Prior to Jan 1, 1982		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

Last updated: October 17, 2026

Micronor is a mature, low-cost progestin-only oral contraceptive containing norethindrone 0.35 mg. Its commercial position is driven by generic substitution, contraceptive access policy, pharmacy availability, and competition from newer progestin-only products rather than by patent exclusivity. The original brand has limited publicly disclosed revenue because manufacturers do not report Micronor sales as a standalone financial line item. Norethindrone 0.35 mg remains commercially relevant, but the economic value has shifted from the brand to generic manufacturers and pharmacy channels.

What is Micronor and how is it used?

Micronor is a prescription progestin-only contraceptive, commonly called a “mini-pill.” Each tablet contains 0.35 mg of norethindrone. It is taken daily without a tablet-free interval. The product is used when estrogen-containing contraceptives are unsuitable or undesirable, including in some breastfeeding patients and patients with contraindications to estrogen exposure. The FDA-approved label requires strict daily adherence because the dosing schedule provides a narrower missed-pill margin than many combined oral contraceptives. [1]

Attribute	Micronor
Active ingredient	Norethindrone
Strength	0.35 mg
Dosage form	Oral tablet
Therapeutic class	Progestin-only contraceptive
FDA route	Prescription drug
Original U.S. approval	1973
Reference product NDA	017031
Biological product	No
Current commercial model	Brand plus multiple generic equivalents

Micronor is distinct from Opill, the over-the-counter norgestrel 0.075 mg progestin-only pill approved by FDA in 2023. Opill’s active ingredient, dosage, labeling, and regulatory status differ from Micronor even though both are estrogen-free oral contraceptives. [2]

What is the FDA and Orange Book status of Micronor?

Micronor is an older FDA-approved prescription product with no remaining new-drug exclusivity of commercial significance. The product’s regulatory value is based on an established NDA and a well-known active ingredient, not on a current period of FDA exclusivity.

The FDA Orange Book lists approved drug products, therapeutic equivalence information, patents submitted by NDA holders, and applicable exclusivity data. For a product approved in the 1970s, any original approval exclusivity has expired. Micronor’s present competitive exposure is therefore primarily generic substitution and pricing pressure. [3]

FDA regulatory milestones

Event	Approximate timing
Original Micronor approval	1973
Generic norethindrone 0.35 mg development	Began after reference-product approval and expiration of applicable barriers
OTC Opill approval	2023
Current market structure	Brand and generic prescription products, with a separate OTC progestin-only competitor

Micronor does not receive biologic-reference-product protection, pediatric exclusivity, or a new chemical entity period today. Any remaining regulatory protection would need to arise from a later qualifying innovation, labeling change, or listed patent, rather than from the original approval.

What patents protect Micronor?

Micronor has no commercially meaningful active-ingredient patent barrier. Norethindrone is an established progestin whose core composition and contraceptive use were disclosed decades ago. The original product’s patent and exclusivity position has expired.

Patent estate assessment

Patent category	Current Micronor position
Active-ingredient patent	Expired or commercially irrelevant
Original product patent	Expired
New chemical entity exclusivity	Expired
Formulation patent	No material current barrier publicly associated with the legacy product
Method-of-use patent	No material current barrier identified for standard contraceptive use
Manufacturing patent	No barrier that prevents routine generic production
Orange Book blocking patent	No material barrier expected for market entry

Micronor’s formulation is comparatively simple: a low-dose immediate-release oral tablet. The product does not depend on a complex delivery device, depot system, biologic manufacturing process, or proprietary controlled-release technology. Generic manufacturers can compete through abbreviated new drug applications using the established reference product and conventional tablet manufacturing.

When did Micronor lose exclusivity?

Micronor lost practical exclusivity decades ago. The drug’s 1973 approval placed it outside the period of modern commercial protection that applies to recently launched small-molecule medicines. The market has had generic norethindrone 0.35 mg alternatives for many years.

The relevant commercial conclusion is straightforward: Micronor is a mature multi-source product. A generic entrant does not need to overcome a current branded patent moat. It must satisfy FDA approval requirements, demonstrate bioequivalence where applicable, establish manufacturing compliance, and obtain commercial distribution.

How many patents cover Micronor today?

No meaningful current patent count can be used to support a Micronor market-exclusion thesis. Legacy patents may appear in historical patent databases or relate broadly to steroid chemistry, contraceptive combinations, or manufacturing methods. Those records do not necessarily create an enforceable barrier to generic norethindrone 0.35 mg tablets.

Patent analysis should distinguish between:

Historical patents associated with norethindrone or oral contraception.
Patents listed for the specific Micronor reference product.
Expired patents.
Active patents that could support a Paragraph IV suit.
Patents covering a different product, strength, route, or formulation.

On that basis, Micronor has a weak current patent estate. Its competitive risks are commercial and regulatory rather than litigation-driven.

Are there Paragraph IV challenges or Micronor patent lawsuits?

Micronor is unlikely to generate substantial current Paragraph IV litigation because the product lacks a valuable active patent platform. Paragraph IV litigation generally matters when an ANDA applicant certifies that a listed patent is invalid, unenforceable, or not infringed. A legacy norethindrone tablet with no commercially material blocking patent does not present the same litigation profile as a recently launched specialty drug.

No major current litigation campaign is associated with Micronor comparable to disputes involving branded medicines with high annual sales and multiple Orange Book patents. There is also no apparent settlement structure that would delay generic entry for a material period.

Litigation and settlement exposure

Issue	Micronor assessment
Paragraph IV risk	Low
Patent-infringement litigation	Low
Authorized-generic strategy	Possible but not central to market structure
Reverse-payment settlement risk	Low
Injunction risk	Low
Launch-at-risk dynamics	Limited

The absence of litigation value does not eliminate ordinary supply, manufacturing, trademark, or labeling disputes. It does remove the principal patent-based mechanism for delaying generic competition.

What generic products compete with Micronor?

Generic norethindrone 0.35 mg tablets compete directly with Micronor. Marketed names have included Camila, Errin, Heather, Jencycla, Norlyroc, and Incassia, although individual products may enter, exit, or change manufacturers over time. Many prescriptions are dispensed under the generic name rather than a brand name.

Product group	Active ingredient	Prescription status	Competitive relationship
Micronor	Norethindrone 0.35 mg	Prescription	Reference brand
Generic norethindrone tablets	Norethindrone 0.35 mg	Prescription	Direct substitutes
Slynd	Drospirenone 4 mg	Prescription	Differentiated progestin-only competitor
Opill	Norgestrel 0.075 mg	OTC	Adjacent progestin-only competitor
Combined oral contraceptives	Estrogen plus progestin	Prescription or other access models	Broader contraceptive substitutes

Slynd competes through a newer formulation and different progestin profile. Its commercial model depends more heavily on brand pricing, insurance coverage, and patient preference. Opill expands the estrogen-free oral contraceptive category through nonprescription access, but it does not directly replace Micronor on an active-ingredient basis.

What formulations are protected by Micronor patents?

Micronor is an immediate-release oral tablet. There is no current evidence of a commercially material proprietary delivery system attached to the product. The formulation’s simplicity reduces technical differentiation and manufacturing barriers.

The primary formulation risks are operational:

Consistent low-dose content uniformity.
Stability and packaging compliance.
Good manufacturing practice compliance.
Reliable API sourcing.
FDA approval maintenance.
Product availability across wholesalers and pharmacies.

These requirements matter commercially but do not create durable exclusivity comparable to extended-release, injectable, implantable, transdermal, or device-linked contraceptive technologies.

How strong is the Micronor patent estate?

Micronor’s patent estate is weak by branded-pharmaceutical standards. Its strengths are regulatory familiarity, physician recognition, and established clinical use. Its weaknesses are the absence of meaningful exclusivity, limited formulation differentiation, generic substitution, and low unit pricing.

Patent-estate factor	Assessment
Remaining exclusivity	Minimal
Active ingredient differentiation	Low
Formulation complexity	Low
Generic substitution pressure	High
Litigation leverage	Low
Manufacturing barrier	Low to moderate
Brand pricing power	Low
Long-term patent value	Low

Micronor’s commercial durability comes from continued demand for progestin-only contraception, not from patent protection.

What drives Micronor market dynamics?

Micronor demand is shaped by contraceptive access, prescribing preferences, patient eligibility, and supply continuity. The product remains relevant for patients who should avoid estrogen or prefer a progestin-only method. Its low price can support access in cash-pay and underinsured segments.

Principal demand drivers

Estrogen-free contraceptive demand.
Patients with certain thrombotic risks, migraine patterns, postpartum considerations, or breastfeeding needs may receive progestin-only contraception.
Low acquisition cost.
Generic norethindrone is generally less expensive than branded newer alternatives.
Provider familiarity.
Decades of clinical use reduce adoption friction.
Coverage and formulary placement.
Health plans often favor generic norethindrone before higher-cost branded products.
Access expansion.
OTC progestin-only contraception may expand the category while also diverting some demand from prescription products.
Supply reliability.
In a low-margin market, manufacturing interruptions can affect availability even when demand is stable.

The market is price-sensitive. Pharmacy benefit managers and insurers can move prescriptions toward the lowest-cost therapeutically appropriate product. Micronor therefore has limited ability to raise prices without losing volume to generics or alternative progestin-only products.

What is Micronor’s financial trajectory?

Micronor-specific revenue is not separately disclosed in the public financial reporting of the companies associated with the product. The brand should be modeled as a mature, low-growth or declining-revenue product unless a manufacturer reports a distinct commercial expansion.

The financial trajectory has four stages:

Period	Financial profile
Early commercialization	Brand-led revenue supported by product exclusivity and physician adoption
Generic entry	Volume migration and price compression
Mature multi-source market	Low unit prices, fragmented supplier base, limited brand leverage
Current outlook	Stable underlying contraceptive demand but weak brand economics

Micronor’s revenue exposure is likely modest relative to large pharmaceutical products. Its economic value is more likely to appear in portfolio-level generic or established-product revenue than as a separately material brand asset.

Revenue sensitivity

Variable	Effect on Micronor economics
Generic share increase	Reduces brand volume and price
Formulary preference	Can preserve prescription volume but favors lowest-cost supplier
OTC progestin-only expansion	May shift some demand away from prescription products
Supply disruption	Can temporarily increase demand for available suppliers
Contraceptive access expansion	Supports category demand
Newer branded products	Erodes higher-value patient segments
Reimbursement compression	Reduces manufacturer and pharmacy margins

A temporary shortage affecting one or more generic suppliers could improve Micronor dispensing volume if the brand remains available. That benefit would likely be episodic rather than structural.

Which companies are challenging Micronor commercially?

The principal challengers are generic manufacturers, branded progestin-only contraceptive companies, and OTC contraceptive suppliers. Competition is fragmented rather than concentrated in a single patent challenger.

Competitive groups

Generic manufacturers of norethindrone 0.35 mg.
Manufacturers of drospirenone 4 mg products such as Slynd.
Perrigo and other OTC contraceptive participants associated with Opill distribution.
Manufacturers of combined oral contraceptives.
Long-acting reversible contraceptive providers, including implant and intrauterine-device manufacturers.

Long-acting contraceptives compete on duration, adherence, and effectiveness rather than direct tablet price. They can reduce the addressable market for daily oral contraception but do not eliminate demand for short-term, reversible, patient-controlled oral products.

What generic launch scenarios exist for Micronor?

Because generic entry is already established, the relevant scenarios concern additional entrants, supplier exits, and channel shifts.

Base case

Generic norethindrone remains the dominant volume channel. Micronor retains a small brand segment supported by prescribing continuity, patient preference, or pharmacy availability.

Upside case

A generic shortage, brand supply advantage, or renewed demand for estrogen-free contraception temporarily increases Micronor volume. The effect is limited by the availability of alternative generic products.

Downside case

Further generic price erosion, formulary exclusion, or OTC substitution reduces brand prescriptions. Micronor becomes a residual product with limited commercial importance.

Regulatory-access case

Broader contraceptive access increases total progestin-only pill utilization. Micronor benefits only if prescribers and payers continue to favor norethindrone over newer prescription and OTC options.

Does Micronor have biosimilar risk?

No. Micronor is a small-molecule tablet, not a biologic. Biosimilar competition does not apply. The relevant competitive framework is ANDA-based generic substitution, therapeutic alternatives, OTC conversion, and pharmacy benefit management.

What licensing deals affect Micronor?

No major recent licensing transaction is publicly associated with Micronor that changes its exclusivity or financial outlook. The product’s commercial history has involved established pharmaceutical ownership, distribution, and generic competition rather than a high-value platform license.

Any transaction involving Micronor would likely be evaluated as part of a broader established-products portfolio. Valuation would depend on net sales, gross margin, supply commitments, manufacturing rights, and distribution economics rather than patent duration.

What is the geographic coverage of Micronor?

Micronor is primarily relevant to the U.S. prescription market. Norethindrone-based progestin-only contraceptives are also marketed internationally under different brand names, strengths, regulatory labels, and commercial owners. Global analysis requires product-by-product verification because approval status, naming, reimbursement, and OTC access differ by country.

The U.S. market remains the most important jurisdiction for Micronor’s recognized brand identity, Orange Book status, and ANDA substitution analysis.

Key Takeaways

Micronor is a norethindrone 0.35 mg progestin-only oral contraceptive approved in the U.S. in 1973.
Its original exclusivity has expired, and its current patent estate is commercially weak.
Generic norethindrone products are the principal direct competitors.
Paragraph IV litigation, settlement risk, and patent-based generic delay are low.
Micronor is not a biologic and has no biosimilar exposure.
Financial reporting does not separately disclose Micronor revenue.
The brand’s likely trajectory is mature, low-growth, and exposed to price erosion.
Category demand is supported by estrogen-free contraceptive needs and access expansion.
Opill is an adjacent OTC competitor with a different active ingredient and dose.
Slynd is a higher-value branded progestin-only competitor with differentiated dosing and commercial positioning.

FAQs

Is Micronor still protected by a patent?

No commercially meaningful patent protection is expected to block generic norethindrone 0.35 mg competition. The product’s original patent and exclusivity periods expired long ago.

Is Micronor the same as Opill?

No. Micronor contains norethindrone 0.35 mg and is prescription-only. Opill contains norgestrel 0.075 mg and is an FDA-approved OTC product.

Can a generic manufacturer launch Micronor without a patent settlement?

Yes. Generic norethindrone products have already entered the market, and no material settlement-based delay is central to current competition.

Does Micronor generate material revenue for its manufacturer?

Public filings do not separately identify Micronor revenue. The product is best treated as a mature portfolio asset rather than a major standalone revenue driver.

What is the main commercial risk to Micronor?

The main risk is continued substitution by lower-priced generics and newer progestin-only products, compounded by formulary pressure and possible migration to OTC contraception.

References

U.S. Food and Drug Administration. (n.d.). Micronor (norethindrone) tablets, USP prescribing information. https://www.accessdata.fda.gov
U.S. Food and Drug Administration. (2023). FDA approves first nonprescription daily oral contraceptive. https://www.fda.gov/news-events/press-announcements/fda-approves-first-nonprescription-daily-oral-contraceptive
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files
U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	76
Clinical Trials:	2
Patent Applications:	3,889
What excipients (inactive ingredients) are in MICRONOR?	MICRONOR excipients list
DailyMed Link:	MICRONOR at DailyMed

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