When do the patents on UNISOM expire, and when will generic UNISOM be available?

Sponsor	Phase
Hospira, Inc.	Phase 4
University of Pennsylvania	Phase 4
Hospira, now a wholly owned subsidiary of Pfizer	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
Pfizer	UNISOM	doxylamine succinate	CAPSULE;ORAL	019440-001	Feb 5, 1986		DISCN	No	No	⤷ Start Trial	⤷ Start Trial				⤷ Start Trial
Chattem	UNISOM	doxylamine succinate	TABLET;ORAL	018066-001	Approved Prior to Jan 1, 1982		OTC	Yes	Yes	⤷ 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: February 19, 2026

UNISOM, a non-prescription hypnotic agent, has maintained a stable market presence for decades. Its primary active ingredient, Doxylamine succinate, targets histamine receptors to induce sleep. The drug's market position is characterized by consistent demand, a well-established consumer base, and a highly competitive over-the-counter (OTC) sleep aid segment.

What is the Current Market Size and Growth Projection for UNISOM?

The global market for OTC sleep aids is substantial, driven by increasing stress levels, irregular sleep patterns, and an aging population. While specific, granular data for UNISOM's standalone market share is proprietary and not publicly disclosed by its manufacturer, Perrigo Company plc, industry reports offer insights into the broader OTC sleep aid market.

The global OTC sleep aid market was valued at approximately $7 billion in 2023 and is projected to grow at a Compound Annual Growth Rate (CAGR) of 5.5% between 2024 and 2030. This growth is attributed to several factors:

Rising Incidence of Sleep Disorders: Insomnia and other sleep disturbances are increasingly prevalent, affecting a significant portion of the adult population.
Consumer Preference for Non-Prescription Options: Many consumers prefer self-treating mild to moderate sleep issues with readily available OTC products over consulting healthcare professionals and obtaining prescriptions.
Aging Demographics: Older adults are more susceptible to sleep disturbances, contributing to sustained demand for sleep aids.
Increased Awareness and Marketing: Greater public awareness of sleep health and aggressive marketing by manufacturers have boosted consumer engagement with OTC sleep aid products.

UNISOM competes in this expansive market against a range of products, including other antihistamine-based sleep aids, herbal supplements (e.g., valerian root, melatonin), and other drug classes. Its established brand recognition and accessibility position it as a significant player within the antihistamine sub-segment of the OTC sleep aid market.

Who are the Key Competitors for UNISOM?

The competitive landscape for UNISOM is robust, with numerous brands vying for consumer attention in the OTC sleep aid category. Competitors can be broadly categorized by their active ingredients and market approach.

Major Antihistamine-Based Competitors:

These products utilize similar pharmacological mechanisms to UNISOM, primarily by blocking histamine H1 receptors.

ZzzQuil: Manufactured by Vicks (Procter & Gamble), ZzzQuil is a leading competitor. It also contains diphenhydramine HCl as its active ingredient in some formulations and Doxylamine succinate in others, directly mirroring UNISOM's primary active ingredient. ZzzQuil offers various product formats, including liquids, caplets, and melts, enhancing its market appeal.
Sominex: Historically a strong competitor, Sominex also uses diphenhydramine HCl as its active ingredient. While its market presence may have shifted over time, it remains a recognized brand within the category.
Unisom SleepTabs/SleepGels: Perrigo also offers variations under the UNISOM brand, such as SleepTabs and SleepGels, which contain Doxylamine succinate, directly competing with its own core product line and further segmenting the market.

Melatonin-Based Competitors:

Melatonin is a hormone that regulates the sleep-wake cycle. Its growing popularity has led to a surge in melatonin-based sleep aids.

Nature Made Melatonin: A well-known brand offering various melatonin supplements in different dosages and formulations (e.g., gummies, tablets).
Natrol Melatonin: Another prominent brand with a wide array of melatonin products, often emphasizing specific benefits like rapid release or extended release.
Kirkland Signature Melatonin: Costco's house brand offers a cost-effective melatonin option, appealing to price-conscious consumers.

Herbal and Natural Supplement Competitors:

This segment includes a diverse range of products derived from plants or natural compounds.

Valerian Root Supplements: Brands like NOW Foods and Gaia Herbs offer valerian root extracts, known for their sedative properties.
Herbal Sleep Aids: Numerous brands market blends of herbs such as chamomile, passionflower, and lemon balm, often positioned as gentle, natural sleep solutions.

The competition is characterized by extensive retail placement, aggressive promotional activities, and product innovation in terms of delivery formats and added ingredients (e.g., added botanical extracts). Pricing strategies also play a crucial role, with UNISOM typically positioned as a mid-tier option, balancing brand recognition with affordability.

What is the Patent Landscape for UNISOM and Related Technologies?

UNISOM's active ingredient, Doxylamine succinate, was first patented decades ago. As a well-established generic drug and an OTC product, the original composition of matter patents have long expired. The patent landscape for UNISOM itself is therefore limited to potential patents related to specific formulations, delivery mechanisms, manufacturing processes, or synergistic combinations that have been developed over time.

Original Composition of Matter: The fundamental patent covering Doxylamine succinate has expired. This expiration allowed for generic competition and its widespread use in OTC products.
Formulation Patents: Manufacturers may hold patents on novel formulations of Doxylamine succinate that improve its stability, bioavailability, palatability, or offer extended-release properties. However, these are less common for basic OTC sleep aids and are more likely to be found in prescription drug development.
Delivery System Patents: Patents could exist for specific delivery methods, such as orally disintegrating tablets, novel capsule designs, or liquid formulations that enhance patient compliance or efficacy.
Manufacturing Process Patents: Improvements in the synthesis or purification of Doxylamine succinate, or the methods used to manufacture UNISOM products, could be patented.
Combination Therapies: While less prevalent for a standalone OTC hypnotic, patents might cover formulations combining Doxylamine succinate with other active ingredients for specific sleep-related benefits, though such combinations would require careful regulatory review.

Perrigo, as the primary marketer of UNISOM, likely holds or has licensed patents related to its specific product lines, manufacturing efficiencies, or any unique product features. However, the absence of significant new patent filings directly related to the core Doxylamine succinate molecule indicates that innovation in this area is likely focused on incremental improvements rather than breakthrough discoveries. The primary driver for UNISOM's continued market viability is its established brand, efficacy, and accessibility, rather than proprietary intellectual property on its core active ingredient.

What are the Regulatory Considerations for UNISOM?

UNISOM operates within a well-defined regulatory framework for Over-the-Counter (OTC) drugs in major markets like the United States, Canada, and Europe. The U.S. Food and Drug Administration (FDA) plays a pivotal role in overseeing its marketing, labeling, and safety.

U.S. FDA Regulations:

Monograph System: Doxylamine succinate for use as a sleep-aid is classified as a Category I active ingredient under the FDA's Over-the-Counter Monograph for Cold, Cough, Allergy, Bronchodilator, and Antihistamine Drugs [1]. This means it has been found to be safe and effective for its intended use when labeled and used according to the monograph.
Labeling Requirements: The FDA mandates specific labeling requirements for OTC sleep aids. UNISOM products must clearly state the active ingredient, its purpose (e.g., "nighttime sleep aid"), dosage instructions, warnings, and contraindications. Key warnings typically include drowsiness, potential for impairment, and not to be used for chronic insomnia without consulting a physician.
Good Manufacturing Practices (GMP): Manufacturers of UNISOM must adhere to FDA's GMP regulations, ensuring consistent quality, purity, and potency of the drug product.
Adverse Event Reporting: Like all drug manufacturers, Perrigo is required to monitor and report adverse events associated with UNISOM to the FDA.
Marketing and Claims: Advertising and promotional claims for UNISOM must be truthful and not misleading. They must align with the approved uses and indications as outlined in the product's monograph.

International Regulations:

Regulatory frameworks in other countries (e.g., Health Canada, European Medicines Agency) share similar principles of safety, efficacy, and quality. However, specific monograph requirements and labeling standards may vary, requiring manufacturers to adapt their product formulations and labeling for different markets.

The OTC status of UNISOM, particularly its Doxylamine succinate component, has significantly reduced the regulatory burden compared to prescription drugs. This allows for wider distribution and consumer access. However, ongoing vigilance regarding safety data and adherence to evolving regulatory standards are critical for maintaining its market position. The absence of significant shifts in the regulatory classification or safety profile of Doxylamine succinate has contributed to UNISOM's long-term market stability.

What is the Financial Trajectory and Revenue Generation of UNISOM?

As a product within Perrigo Company plc's Consumer Self-Care Americas segment, UNISOM's specific financial performance is not broken out as a standalone revenue line. However, its contribution is embedded within the overall segment performance, which generally exhibits stable revenue streams from established OTC brands.

Perrigo's Consumer Self-Care Americas segment, which includes UNISOM, is a significant contributor to the company's overall revenue. This segment typically generates several billion dollars annually. The financial trajectory of UNISOM is characterized by:

Stable Demand: The consistent demand for sleep aids, driven by lifestyle factors, ensures a predictable revenue base for UNISOM.
Mature Product Lifecycle: UNISOM is in a mature stage of its product lifecycle. Revenue growth is likely to be modest, driven by market expansion and price adjustments rather than significant market share gains or new product introductions based on novel active ingredients.
Brand Loyalty and Retail Placement: Established brand recognition and strong relationships with major retailers (pharmacies, supermarkets, mass merchandisers) ensure consistent product availability and sales.
Cost of Goods Sold (COGS): As a generic active ingredient, Doxylamine succinate is generally cost-effective to manufacture, contributing to healthy gross margins for the finished product. Perrigo benefits from economies of scale in manufacturing and procurement.
Marketing and Promotional Spend: While UNISOM is a well-known brand, ongoing investment in marketing and promotional activities is necessary to maintain visibility in a crowded OTC market and to counter competitor promotions. This spend impacts net revenue.
Generic Competition Impact: Although UNISOM itself is an OTC product and not a patented prescription drug facing direct generic equivalents, the broader OTC sleep aid market does include numerous brands with similar active ingredients or alternative mechanisms, creating price pressure and requiring effective differentiation.
Impact of Inflation and Supply Chain: Like all consumer products, UNISOM's profitability can be influenced by raw material costs, manufacturing expenses, and logistics, particularly in periods of inflation or supply chain disruptions.

While precise figures for UNISOM are undisclosed, its financial trajectory is aligned with the stable, cash-flow generating profile of mature OTC brands. Perrigo's overall strategy for such brands involves efficient manufacturing, broad distribution, and targeted marketing to maintain market share and profitability.

What are the Future Outlook and Potential Risks for UNISOM?

The future outlook for UNISOM remains one of continued market presence, driven by its established efficacy and consumer trust. However, several factors could influence its trajectory.

Future Outlook:

Sustained Demand: The underlying drivers for sleep aid consumption—stress, lifestyle changes, and an aging population—are expected to persist, ensuring continued demand for UNISOM.
Brand Resilience: UNISOM's long-standing brand recognition offers a significant competitive advantage. Consumers familiar with the brand are likely to continue purchasing it.
Expansion in Emerging Markets: As healthcare access and consumer spending power increase in emerging economies, there may be opportunities for market expansion, provided regulatory pathways are navigated.
Product Line Extensions: Perrigo could potentially leverage the UNISOM brand for line extensions, such as combining Doxylamine succinate with other mild sedatives or complementary ingredients, although such developments would require significant regulatory scrutiny.

Potential Risks:

Increasing Competition from Novel Sleep Aids: The market is seeing a rise in new product categories, particularly melatonin-based supplements and prescription-to-OTC switches of newer drug classes, which may offer perceived advantages in efficacy or side effect profiles to some consumers.
Evolving Regulatory Landscape: While Doxylamine succinate has a long safety record, any new safety concerns or changes in regulatory classification by bodies like the FDA could significantly impact UNISOM. Increased scrutiny on OTC sedative use is a perpetual possibility.
Shifting Consumer Preferences Towards Natural/Herbal Remedies: A growing segment of consumers is seeking "natural" alternatives. If this trend accelerates, it could divert market share from antihistamine-based products.
Marketing by Competitors: Aggressive marketing campaigns by competing brands, particularly those highlighting perceived innovation or unique benefits, can erode market share if UNISOM's marketing efforts are not equally robust or effective.
Health Concerns Regarding Antihistamine Use: While generally safe for occasional use, long-term or widespread use of first-generation antihistamines like Doxylamine succinate has been associated with potential cognitive side effects in some studies, particularly in older adults. Increased public awareness or media attention on these concerns could negatively impact demand.
Pricing Pressures: The highly competitive OTC market inherently leads to pricing pressures, which can affect profit margins if costs increase or competitors engage in aggressive discounting.

Perrigo's strategic management of UNISOM will be crucial. Maintaining cost-efficiency in production, ensuring broad and consistent distribution, and adapting marketing strategies to resonate with current consumer concerns and preferences will be key to navigating these future challenges and opportunities.

Key Takeaways

UNISOM competes in a large and growing global OTC sleep aid market, valued at approximately $7 billion annually and projected to expand at a 5.5% CAGR.
Its primary active ingredient, Doxylamine succinate, has expired composition of matter patents, placing it in a competitive landscape with numerous antihistamine, melatonin, and herbal-based sleep aids. Major competitors include ZzzQuil and Sominex.
Regulatory oversight by bodies like the U.S. FDA classifies Doxylamine succinate as safe and effective under monograph conditions, with strict labeling and manufacturing requirements.
UNISOM's financial contribution is embedded within Perrigo Company plc's stable Consumer Self-Care Americas segment, reflecting mature product lifecycle economics with predictable, albeit modest, revenue streams.
Future outlook is positive due to sustained demand and brand resilience, but risks include intensifying competition from novel sleep aids, evolving consumer preferences for natural products, and potential shifts in regulatory scrutiny.

Frequently Asked Questions

1. Is UNISOM a prescription drug or an over-the-counter (OTC) medication?

UNISOM is an over-the-counter (OTC) medication, meaning it is available for purchase without a prescription from a healthcare provider.

2. What is the primary active ingredient in UNISOM that helps with sleep?

The primary active ingredient in UNISOM is Doxylamine succinate, an antihistamine that causes drowsiness.

3. Does UNISOM have any known long-term side effects?

While generally considered safe for occasional use as directed, long-term use of first-generation antihistamines like Doxylamine succinate has been associated in some studies with potential cognitive issues, particularly in older adults. Consumers should consult healthcare professionals for chronic insomnia.

4. How does UNISOM compare to melatonin supplements for sleep?

UNISOM (Doxylamine succinate) is an antihistamine that works by blocking histamine receptors to induce sleep. Melatonin supplements, on the other hand, contain a hormone that regulates the sleep-wake cycle. They operate through different mechanisms and may be preferred by different individuals based on their sleep issues and personal responses.

5. Can UNISOM be taken daily for an extended period?

UNISOM is intended for short-term use. The product labeling generally advises consulting a doctor if sleep difficulties persist for more than two weeks, indicating it is not recommended for chronic, daily use without medical supervision.

Citations

[1] U.S. Food & Drug Administration. (2023, April 7). Over-the-counter (OTC) drugs. Retrieved from https://www.fda.gov/drugs/over-the-counter-otc-drugs

US Patents:	0
Applicants:	2
NDAs:	2
Raw Ingredient (Bulk) Api Vendors:	92
Clinical Trials:	2
Patent Applications:	1,551
DailyMed Link:	UNISOM at DailyMed

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