The Legality of Trends: How Close Can a Dupe Get?

[1] 

“Dupe” culture is one of many trends that has exploded over the last several years on TikTok.[2] Short for “duplicate”, dupes are knockoff items of luxury products, often being sold at much cheaper prices than the original.[3] Unlike counterfeit items, dupes are usually sold without the trademarked logos of the original product.[4] Dupes are no longer being viewed as products for people who cannot afford the original, but more as a ‘badge-of-honor’ for acquiring a bargain version of the more expensive original.[5] TikTok videos using the hashtag “dupe” have acquired billions of views, with creators even using their platforms to promote dupes to their fans.[6] Although this trend has been great for consumers, this has had severe implications on fashion brands, raising questions regarding the possible infringement of their intellectual property.[7]

Trademark, Trade Dress, and Design Patents

A trademark is "any word, name, symbol, or device" that is used to identify and distinguish the products sold by one person from all other products.[8] The purpose of trademarks is to ensure the consumer can easily identify products and further the quality of a product based on the mark.[9] Trademarks are registered with the United States Office of Patents and Trademarks and can provide protection indefinitely.[10] 

Trade dress is a subset of trademark law, protecting the total image of a product that identifies its source in the marketplace, either involving the packaging and labeling of the good or the product design.[11] Trade dress must be capable for distinguishing the goods from others in the marketplace.[12] Product packaging trade dress can be inherently distinctive and protected under trademark law without proof of secondary meaning. [13] Product design trade dress cannot be inherently distinctive and must show it has acquired distinctiveness through secondary meaning.[14]

Additionally, many fashion companies rely on design patents to protect the aesthetic portions of their products.[15] Unlike trade dress, design patents only provide protection for fifteen years from the date the patent was issued and provides an exclusive right to sell that design.[16] Companies use this dual strategy to diversify their Intellectual Property (“IP”) portfolio and further protect their products, excluding competition.[17]

Lululemon v. Costco

The latest brand cracking down on dupes is the luxury athleisure brand, Lululemon.[18] The brand has filed suit against Costco on June 27, 2025, alleging that the wholesale corporation is selling extremely similar knockoff versions of Lululemon’s products, such as jackets and sweatshirts, which infringe upon its trademark, design patent, and trade dress rights.[19] Lululemon argues that Costco’s sale of products that are so similar in design is causing reputational harm to the brand as it is misleading consumers into believing Costco is an authentic supplier of Lululemon products.[20] These Costco dupes have not gone unnoticed by TikTok either, with viral videos sharing the athletic wear being sold at Costco as being “Lululemon dupes”. [21]

To succeed on its trademark and trade dress infringement claims, Lululemon has the burden to prove there was a likelihood of consumer confusion under the Sleekcraft factors.[22] This test will look to issues such as the strength of Lululemon’s brand, Costco’s use of similar products, the similarity between the products, any evidence of actual confusion in consumers, and Costco’s intent in selling the goods.[23] Lululemon also must show that their product design trade dress have formed secondary meaning in the minds of consumers because product design trade dress cannot be inherently distinctive.[24]

Inspiration or Infringement?

Because dupes are sold without the trademark or logo of authentic luxury brands, this raises the issue of ambiguity over the legality of dupes.[25] For instance, the present case claims trade dress infringement based on the similar look and feel of the products, but Costco is not selling the products using Lululemon’s trademarked logo or any intimation of it.[26] So where can brands draw the line between a product that is simply similar to their own versus a product that infringes upon its rights?

Lululemon has registered certain product features as trade dress and also holds design patents issued by the USPTO.[27] In the upcoming litigation, Lululemon is expected to argue that Costco’s sale of “dupes” infringes its trade dress, trademarks, and design patents by creating a likelihood of confusion and diluting the distinctiveness of its brand, even if consumers knowingly purchase cheaper alternatives.[28] Costco, on the other hand, will likely defend itself by arguing that no reasonable consumer is confused, that many of Lululemon’s product features are functional and therefore not protectable under trade dress law, and that its designs represent lawful competition rather than copying.[29] The outcome will depend on whether the court views Lululemon’s design elements as distinctive intellectual property or as common features of athleisure wear available for all to use.[30]

The Lululemon-Costco dispute is only one within the broader issue of the popularization of dupe culture and its conflict with the intellectual property rights of brands.[31] As an increasing number of brands struggle with this issue, it is important to question whether IP law as it stands now can keep up with the changing landscape of social trends and the pressures it applies to the creative rights of brands.[32] Where the law remains ambiguous on the legality of dupes, it is imperative to consider if fashion brands are being adequately protected from having to compete with products that are copycats of their own.[33]   

 References

[1] Photo by P.L. on Unsplash, https://unsplash.com/photos/a-shopping-mall-with-a-sign-that-says-the-store-is-open-bzZbN30D9E4.

[2] See Ana Teresa Solá, With Gen Z, Millennials Now the Biggest ‘Dupe’ Shoppers, Online Culture has ‘Flipped the Script,’ Analyst Says, CNBC (Oct. 31, 2023), https://www.cnbc.com/2023/10/31/gen-z-millennials-are-shopping-for-dupes-the-most-report-finds.html (explaining how roughly 49% of Gen Z and 44% of millennials have purposefully bought dupe of more expensive premium brand).

[3]See id. (describing reasoning behind individuals purchasing dupes).

[4] See id. (highlighting difference between counterfeits and dupes).

[5]See Ali Watkins, Lululemon Sues Costco Over Selling ‘Dupes.’ What’s Behind the Case?, New York Times (July 1, 2025), https://www.nytimes.com/2025/07/01/us/lululemon-costco-dupes-lawsuit.html.

[6] See id.

[7] See Erica Han, Georgina Jones Suzuki, and Sabrina Kim, Dupes Boom Spurs IP Risks, Opportunities For Investors, Law360, (July 7, 2025), https://www.law360.com/articles/2358324/dupes-boom-spurs-ip-risks-opportunities-for-investors.

[8] See 15 U.S.C. § 1127 (2021) (“to identify and distinguish his or her goods, including a unique product, from those manufactured or sold by others and to indicate the source of the goods, even if that source is unknown”).

[9] See Timothy M. Barber, High Court Takes Right Turn in TrafFix, But Stops Short of the Finish Line: An Economic Critique of Trade Dress Protection for Product Configuration, 7 Marq. Intell. Prop. L. Rev. 259, 262 (2003).

[10] See U.S. Patent & Trademarks Office, What is a Trademark? (last visited Sept. 24, 2025), https://www.uspto.gov/trademarks/basics/what-trademark (explaining to have strong national rights, registration is required).

[11] See Barber, supra note 9, at 263.

[12] See id. 

[13] See Two Pesos, Inc. v. Taco Cabana, Inc., 505 U.S. 763, 776 (1992) (holding if trade dress is inherently distinctive, secondary meaning not required for successful trade dress infringement claim).

[14] See Wal-Mart Stores, Inc. v. Samara Bros., Inc., 529 U.S. 205, 209 (2000) (ruling for unregistered trade dress, product’s design is distinctive only with secondary meaning).

[15] See Elizabeth D. Ferrill & Sydney N. English, Yin and Yang: Design Patents and Trade Dress Rights, Finnegan (July 27, 2015), https://www.finnegan.com/en/insights/articles/yin-and-yang-design-patents-and-trade-dress-rights.html (highlighting overlap in trade dress and design patents).

[16] See 35 U.S.C § 171 (2021) (“Whoever invents any new, original and ornamental design for an article of manufacture may obtain a patent”); see also MPEP § 1504 (9th ed. Rev. Nov. 1, 2024) (“In design patent applications, ornamentality, novelty, non-obviousness, enablement, and definiteness are necessary prerequisites to the grant of a patent.”); Ferrill & English, supra note 15 (highlighting rights associated with design patents).

[17] See Ferrill & English, supra note 15 (explaining dual strategy of design patents and trade dress in IP portfolio).

[18] See Wyatte Grantham-Philips and Anne D’Innocenzio, Lululemon’s lawsuit against Costco highlights the rise of fashion ‘dupes’, AP, (July 2, 2025), https://apnews.com/article/costco-lululemon-birkin-fashion-dupes-tiktok-2def75bcaf37e81ccb0065fe67b82101.

[19] See Compl. for Damages & Injunctive Relief ¶ 3, Lululemon Athletica Canada, Inc. v. Costco Wholesale Corp., No. 2:25‐cv‐05864‐FLA‐AJR, (C.D. Cal. filed June 27, 2025) (“Costco has unlawfully traded upon Plaintiffs’ reputation, goodwill and sweat equity by selling unauthorized and unlicensed apparel employing knockoff, infringing versions of Plaintiffs’ well-known trade dress and design patents”); see also Blake Brittain, Lululemon sues Costco for allegedly ripping off clothing designs, Reuters, (June 27, 2025),  https://www.reuters.com/legal/litigation/lululemon-sues-costco-allegedly-ripping-off-clothing-designs-2025-06-27/.

[20] See id.

[21] See Erin Davis, Lululemon Is Suing Costco For Allegedly Selling ‘Knockoffs’ of Its Leggings, Entrepreneur (July 1, 2025), https://www.entrepreneur.com/business-news/lululemon-sues-costco-over-selling-dupes-of-its-leggings/494087.

[22] See AMF Inc. v. Sleekcraft Boats, 599 F.2d 341, 348-53 (9th Cir. 1979) (explaining factors used to prove likelihood of confusion including (1) strength of Plaintiff’s mark, (2) Defendant’s use of mark, (3) similarity of two marks, (4) whether there was actual confusion, (5) intent of the Defendant, (6) whether marks are sold in similar marketplaces, (7) consumer’s degree of care regarding purchasing mark, and (8) product line expansion)

[23] See 15 U.S.C. §§ 1114(1), 1125(a) (explaining how this test establishes that reasonable prudent consumer is likely to be confused by two marks).

[24] See Wal-Mart Stores, Inc., 529 U.S. at 209.

[25] See Solá, supra note 2; see also Complaint ¶ ¶83-90, Sol de Janeiro USA, Inc. v. MCoBeauty Pty Ltd, No. 1:24‐cv‐08862 (S.D.N.Y. Nov. 20, 2024) (alleging infringement of trade dress with dupe).

[26] See Lululemon Compl. ¶ 7 (alleging the similarity between Lululemon’s trade dress with ABC pants and Costco’s imitation pants); see also LeKeisha Suggs, Beyond the Lookalike: How Dupes are Testing the Boundaries of IP Law, UnitedLex, https://unitedlex.com/insights/beyond-the-lookalike-how-dupes-are-testing-the-boundaries-of-ip-law/..

[27] See U.S. Design Patent No. D989,442; see also U.S. Design Patent No. D1,035,219; U.S. Trademark Reg. No. 4,333,759.

[28] See Suggs, supra note 26.

[29] See id. 

[30] See id.

[31] See Abby Hughes, Lawsuits over dupes are popping up in courts. But can dupes be illegal?, CBC, (July 11, 2025), https://www.cbc.ca/news/business/are-dupes-illegal-1.7581922.

[32] See Suggs, supra note 26.

[33] See Hughes, supra note 31.