Lululemon sues Costco over alleged ‘dupe’ apparel, but can it win the battle?

Lululemon, the high-end athletic apparel brand, has filed a federal lawsuit against Costco, accusing the retail giant of selling and manufacturing low-cost imitations of some of its most popular products. The lawsuit, filed in California, claims Costco’s offerings—including the Danskin Half-Zip Pullover ($8 vs. Lululemon’s $118 SCUBA pullover), Spyder Women’s Yoga Jacket ($22 vs. Lululemon’s $128 Define jacket), and Kirkland 5 Pocket Performance Pant ($10 vs. Lululemon’s $128 ABC Pant)—are unauthorized replicas that infringe on Lululemon’s patents and trade dress.

Lululemon alleges Costco’s products are designed to closely mimic the look and feel of its originals, potentially confusing consumers and harming Lululemon’s brand reputation. The lawsuit cites violations of the Lanham Act, patent infringement, and breaches of California’s Unfair Business Practices Act, seeking damages for lost revenue and “substantial harm” to the brand.

This legal battle is part of a larger trend fueled by “dupe culture,” where consumers—often inspired by viral TikTok trends—actively seek out cheaper alternatives to luxury products. The hashtag #dupe has amassed over 6 billion views on TikTok, reflecting the mainstream acceptance of buying and sharing imitation goods.


However, legal experts say Lululemon faces an uphill battle. Trademark attorney Karl Zielaznick explains that to win, Lululemon must prove not only that Costco’s products are copies, but that they genuinely mislead consumers into thinking they are buying authentic Lululemon items. “Customers often recognize they are not purchasing a $5,000 watch for $100... They understand it’s a different, counterfeit product,” Zielaznick told Forbes. Courts have previously ruled against brands in similar cases, even when imitation was admitted, unless there was clear evidence of consumer confusion and intent to deceive.

Lululemon claims it previously warned Costco in November 2024 about selling hoodies that copied its SCUBA design, and while Costco briefly removed some items, the retailer allegedly resumed sales of similar products. Costco has not yet commented publicly on the lawsuit.