Lululemon has filed a lawsuit against Costco, alleging that the wholesale giant is selling unauthorized versions of its popular $128 pants and other high-demand athleisure wear. According to the complaint, Costco’s private-label brand, Kirkland, is offering apparel that closely mimics Lululemon’s signature designs—such as the ABC pants, Define jackets, and Scuba hoodies—at prices dramatically lower than those of the original products. Lululemon claims this practice not only infringes on its design patents and trade dress but also damages its brand reputation and confuses consumers about the authenticity of the products they are purchasing.

The lawsuit, filed in a California federal court, asserts that Costco has “unlawfully traded” on Lululemon’s reputation, goodwill, and investment in product innovation by selling what it calls “knockoff” or “dupe” versions of its clothing. Lululemon’s legal team provided side-by-side comparisons in the filing, highlighting the strong resemblance between items such as the $118 Lululemon Scuba hoodie and a similar Kirkland product retailing for about $8. The company argues that these similarities are not coincidental and are designed to mislead shoppers into believing the Kirkland products are made or endorsed by Lululemon.

Lululemon’s complaint also points to the growing popularity of so-called “Lululemon dupes” on social media, with influencers using hashtags like #LululemonDupes to promote less expensive alternatives that are difficult to distinguish from the originals. The company alleges that this trend amplifies consumer confusion and further erodes the value of its intellectual property. Lululemon is seeking a court order to stop Costco from selling the disputed products, as well as full financial compensation for the alleged damages to its brand and business.

Costco has not immediately responded to requests for comment regarding the lawsuit. Lululemon emphasized in its statement that it invests heavily in research, development, and design, and that it takes the protection of its intellectual property “very seriously.” The company maintains that legal action is necessary to defend its brand against retailers it accuses of copying rather than competing fairly in the marketplace.