Investors are scrambling to adjust, after the telehealth specialist Hims & Hers said it would stop selling an alternative to Novo Nordisk's Wegovy and Ozempic weight-loss drugs. Hims stock stood about 17% lower at under $42.

Hims & Hers said on Monday that it may no longer be able to sell compounded versions of the weight-loss drug made by Novo Nordisk because its pathway to do so closed when the U.S. FDA declared Friday that the drug's shortage was over.

Weight-loss drugs aren’t just slimming waists; they create a $100 billion market opportunity. With plenty up for grabs, pharmaceutical giants like Eli Lilly and Company (LLY), Novo Nordisk (NVO), and Amgen (AMGN) are betting big on next-generation weight loss treatments to dominate this booming market.

Hims & Hers Health Inc. shares lost as much as a fifth of their value in after-market trading Monday after the company said that it will soon stop selling some compound weight-loss drugs.

Shares of Hims & Hers Health tumbled 18% premarket on Tuesday as Wall Street analysts questioned the telehealth provider's lofty sales forecast in the face of looming restrictions on compounded weight-loss drugs.

After the FDA removed semaglutide injection products from a shortage list, compounders like Hims have 60-90 days to stop making copies.