Secondhand fashion platform Poshmark revealed a 103% increase in plus-size clothing listings, including a 103% increase in 3XL, 80% in 4XL, and 73% in 5XL listings over the past two years, Vogue Business reported. Poshmark also noted a 78% increase in new items with the term “weight loss” in a description or listing title.

“With the rise of these new medications, we expect that Poshmark will support our customers through yet another life change,” Poshmark cofounder and senior vice president of seller experience Tracy Sun told Vogue Business. “We’re noticing shifts in supply and demand, and we monitor these trends closely to stay attuned to the customer.”

Combined with Americans getting rid of plus-size clothes is GLP-1 med users’ hunt for a new wardrobe. Jennifer Hyman, cofounder and CEO of designer apparel rental platform Rent the Runway, noticed that more of its consumers are purchasing smaller sizes than they have in the past 15 years. High-end fashion and luxury brands like Lafayette and Amarra are also aware of the trend.

There’s good reason these buying patterns could be associated with a growing base of consumers using weight-loss drugs, Leigh O’Donnell, market research firm Kantar’s consulting division vice president, told Fortune. Those in the process of losing weight may be cycling through different sizes of clothing, leading them to secondhand markets as opposed to buying new clothes. If you’re someone who’s getting rid of old clothes that no longer fit, you may accrue points through resale platforms, which incentivizes you to buy on those platforms, O’Donnell argued.

But for those who are reaching their target weight for the first time, there’s an added appeal to shopping: the prospect of developing a zhuzhed-up personal style. As Ozempic users change shopping habits for groceries and household goods, leaning toward items with denser nutrients or greater quality, they may have the same philosophy regarding their wardrobe.

“Especially if you’re reinventing yourself, you maybe don’t want to go for throwaway clothing,” O’Donnell said.

How Ozempic is shaking up consumer products

With about one in eight Americans having tried Ozempic or another GLP-1 inhibitor like Wegovy, it’s no surprise that the changes in body shapes and sizes would spur action from the fashion world. The industry has struggled amid weak consumer confidence, and as of May, apparel and accessory sales fell 0.9% year over year, according to data from the U.S. Census Bureau.

The Ozempic shake-up could be even better news for the secondhand luxury industry, which has bucked the downward trend of the fashion sector. High-end resale has already grown twice as fast as the primary luxury market as inflation-struck consumers with expensive tastes look for affordable alternatives to their favorite brands. The luxury resale market reached $49 billion in 2023, according to management consultancy Bain & Co., and it’s expected to grow 1% to 4% this year.

Other industries have already jumped at the opportunity to appeal to the growing consumer base of Ozempic users. Nestlé rolled out a line of smaller-portioned frozen meals specifically for users of GLP-1 meds. WeightWatchers launched a plan offering weight-loss drugs like Wegovy.

But there’s a risk for these large-scale changes, as the long-term impact of these drugs is largely unknown, with many users regaining weight after they stop taking the drugs. While Ozempic may be a craze now, its lasting impact on consumer products remains difficult to determine.

There are risks involved for the fashion market trying to keep up with the times. While those on weight-loss drugs may be looking for new clothes, they may not be ready to take the luxury plunge until they reach their desired weight, O’Donnell said.

“Almost everybody that I’ve spoken to qualitatively with GLP-1 says, ‘I’m coming along, but I’m not quite there yet, so I’m going to hold back,’” she said.

This isn’t just a problem for secondhand markets. As clothing sizes shrink, clothing producers may experience growing pains trying to adapt, noted Prashant Agrawal, founder and CEO of AI-based forecasting firm Impact Analytics. The firm found that as more people use weight-loss drugs, retailers are compensating by changing sizing models to accommodate smaller frames. 

Sizing curves, or the array of sizes retailers provide for consumers, has always been a hit-or-miss model for stocking inventory. By introducing the variable of shoppers looking for smaller clothes, it becomes even harder to determine those sizing curves. Get those curves wrong and clothing companies could lose $20 million a year in unused inventory and wasted resources.

“It’s something that retailers need to monitor,” Agrawal said in a statement. “It’s a sustainability issue. We can’t make things that won’t get used.”