Lululemon’s success stems from a combination of factors: awareness of consumer trends embracing look-good, feel-good wellness pursuits; a reputation for providing relatively fashion-forward workout appeal; and pricing that finds a good balance between those aspects. Because Lululemon gear provides both symbolic and functional value, the brand can justify the relatively expensive prices it charges for its leggings, jackets, and socks.

But popularity and notoriety can come with their own prices. Noting the popularity of Lululemon apparel, competitors in the crowded athletic and athleisure clothing markets have sought to mimic its success, and its style, by introducing “dupes” or duplicate versions. There’s a vast market in dupes, especially for Lululemon gear, such that #LululemonDupes remains a popular hashtag on social media. According to Lululemon though, some of those dupes cross the line into trademark infringement, as alleged in its suit against Costco.

The suit claims that certain workout pieces sold in Costco—known for its low cost offerings—resemble Lululemon’s proprietary designs too closely. Beyond broad similarities in color, material, shape, or function, as might be accepted in copycat products, it asserts that the items in contention exactly replicate the silhouettes, seams, and accents that the brand has sought to establish as markers of its own, distinctive identity and appeal.

In support of its claims, Lululemon provided evidence involving three product lines: Define jackets, Scuba jackets, and ABC pants. In side-by-side comparisons submitted to the courts, it showed how its Define jacket collection—which it promotes as overwear that can help people transition easily from a strenuous run into everyday chores—features a unique, tailored silhouette, achieved by stitching the back panels together in a novel way. Then it showed how the Jockey Ladies Yoga Jacket carried by Costco featured the same seaming along the back, producing the flattering silhouette that helped make the Define so popular. It also indicated the price difference: $168 for Lululemon’s Define design, $17 for the Costco dupe.

Another jacket, the Scuba from Lululemon, retails at $128 and features a distinctive zipper location on the front, as well as creative pocket placements. The Danskin Half-Zip Hoodie at Costco, selling for $8, displays the exact same zipper and pocket locations. The other example listed in the suit sought to set up a consistent argument, showing how the Kirkland 5-Pocket pants ($20) copy Lululemon’s ABC pant ($128), with almost imperceptible variations in coloring, pant leg style, and sizing.

According to Lululemon, because Costco is so well-known for selling private-label versions of national brands, the dupes create an unacceptable risk of increasing consumers’ confusion. That is, shoppers at Costco likely are aware that, for example, the Kirkland brand diapers on the shelves are made in the same manufacturing plant that Huggies diapers are. Thus, they might be forgiven if they believe that Kirkland-branded jackets or pants that look just like Lululemon versions actually are being produced by Lululemon.

There’s where the problem lies. To maintain its brand strength and price positioning, Lululemon needs to ensure that all its products offer high quality. If consumers get confused and believe that a dupe is made by Lululemon, and then that dupe offers poor quality, it arguably harms the brand’s hard-won position

Notably, only the dupe of the pants carries Costco’s in-house Kirkland brand. The others appear sourced from external manufacturers (i.e., Jockey and Danskin). Still, the company claims that the significant research and development it conducts to ensure that its products function at the standard that customers have come to expect deserves protection as intellectual property that others should not be allowed to copy.

Discussion Questions

1. What is the standard or threshold that applies, when it comes to defining a similar, copycat product as a fair dupe versus an illegal infringement? Has Costco crossed that line, in your opinion?
2. Analyze Lululemon’s pricing strategy, in light of its claims here. Why is it so determined to protect its designs from being mimicked by other firms, especially those that sell at lower prices?

Sources: Blake Brittain, “Lululemon Sues Costco for Allegedly Ripping Off Clothing Designs,” Reuters, June 27, 2025; Eric Goldman, “Analyzing the Lululemon v. Costco Dupe Suit,” Technology & Marketing Law Blog, July 9, 2025; Kelly Tyko, “Lululemon Sues Costco Wholesale for Selling Alleged Dupes,” Axios, July 1, 2025; Micah Barkley, “Lululemon Gets Aggressive About Lookalikes with Costco Lawsuit,” Bloomberg, July 2, 2025