Scroll through TikTok or Instagram for five minutes, and you're bound to see someone showing off their latest "designer dupe." The trend is everywhere, and social media is leading the charge, with influencers pointing their followers to affordable lookalikes and bragging about scoring the same style for a fraction of the price.

Lululemon, famous for its $100-plus leggings and sporty zip-ups, has become prime territory for these budget-friendly alternatives. And this isn't the first time the brand's designs have been copied. In fact, Lululemon says several companies have replicated its apparel in the past, with many of those lookalikes going viral under hashtags like "#LululemonDupes" on TikTok and beyond.

Now, the company is taking formal action. Lululemon has filed a lawsuit against Costco, accusing the retail giant of moving beyond inspiration and into outright imitation.

Inside Lululemon's Lawsuit Against Costco

According to the complaint, Costco is selling clothes that Lululemon says look strikingly similar to some of its most popular items, including the Scuba hoodies, Define jackets, and ABC pants.

One product getting special attention is the Hi-Tec Men’s Scuba Full Zip, which popped up on Costco’s website for just $19.97. Compare that with Lululemon’s typical $100+ price tag for similar pieces, and you can see why this grabbed headlines.

In the lawsuit, Lululemon accuses Costco of “unlawfully trading” on its brand reputation, suggesting the warehouse retailer is benefiting from years of Lululemon’s marketing, design work, and customer loyalty. The company argues that these lookalike products could easily confuse shoppers, especially those already familiar with Lululemon’s signature designs.

At the heart of the case is a legal concept called trade dress infringement. Put simply, it’s the idea that Costco’s products mimic the overall look and feel of Lululemon’s items so closely that consumers might assume there’s a connection between the two brands.

And while it’s no secret that plenty of retailers sell similar styles, Lululemon’s lawsuit makes it clear they believe Costco has crossed the line.

The Rise of Fashion Dupes and the Legal Gray Area

The timing of the lawsuit aligns perfectly with the widespread explosion of fashion dupes, fueled almost entirely by social media.

Influencers regularly spotlight budget-friendly alternatives to high-end brands, giving followers detailed shopping guides to find similar styles for less. And it’s not just activewear getting the dupe treatment. Target, Walmart, and newer players like Quince have all gone viral for their affordable takes on designer goods from Hermès-inspired slippers to Bottega Veneta-style handbags.

Legally speaking, though, not all dupes are considered infringement. Simply selling something that looks similar doesn’t automatically land a company in court. For Lululemon to win this case, they need to prove that Costco’s products are likely to cause “consumer confusion” or that they copy design elements that are distinctive and legally protectable.

And that’s where things get complicated.

Alexandra Roberts, a professor of law and media at Northeastern University, weighed in on the case, calling some of Lululemon’s claims a bit of a stretch. According to Roberts, functional design elements like the “triangle-shaped crotch area” on the ABC pants typically don’t qualify for trademark protection.

Still, she noted that Lululemon does raise some valid points, especially regarding the overall branding and marketing of the Costco products.

Lululemon’s Legal Track Record and What's Next

If this all feels a little familiar, there’s a reason. Lululemon has taken legal action over copycat designs before. Back in 2021, the company sued Peloton, claiming its new activewear line infringed on Lululemon designs. That case didn’t go the distance in court. Instead, it ended with Lululemon and Peloton forming a five-year business partnership. Now, Lululemon is Peloton’s official athletic apparel provider.

Whether Costco and Lululemon will settle, partner up, or take this all the way to trial is still unknown. As of now, Costco hasn’t publicly commented on the lawsuit.

One thing is clear, as long as social media keeps fueling the dupe craze, this will likely not be the last legal battle we see.

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