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COPENHAGEN, Feb 9 (Reuters) - Novo Nordisk's NOVOb.CO shares jumped more than 8% on Monday after telehealth firm Hims & Hers HIMS.N cancelled the launch of a $49 weight-loss pill over the weekend, following legal threats from Novo and the U.S. Food and Drug Administration.

Hims introduced the compounded pill based on semaglutide - a key ingredient in Novo's blockbuster drugs Wegovy and Ozempic - last Thursday, prompting pushback from the Danish drugmaker and regulatory authorities.

Hims said on Saturday that it would stop offering the treatment after holding "constructive conversations with stakeholders."

The swift reversal marks a rare victory in Novo's battle against compounded versions of its GLP-1 drugs. Compounders copy brand-name medicines by combining, mixing or altering drug ingredients.

Hims did not respond to Reuters' questions on Saturday about whether it would continue selling compounded semaglutide injections on its website.

PRICING PRESSURES REMAIN FOR NOVO

Novo Nordisk's shares had already rebounded over 5% on Friday after FDA Commissioner Marty Makary signalled a crackdown on unauthorized compounded GLP-1 medications, which have challenged the drugmaker's pricing power in the weight-loss and diabetes markets.

Novo still faces heavy competition in the rapidly shifting GLP-1 market, however, as rival Eli Lilly LLY.N and multiple compounding pharmacies offer injectable versions of semaglutide.

Novo Nordisk's market value peaked in June 2024, but it has since shed nearly two-thirds of its value. After it flagged "unprecedented price pressure" at its full-year earnings last week, its stock plunged 17%.

Despite pioneering the obesity drug market, those struggles underscore how quickly its dominance has eroded. And with Eli Lilly's oral GLP-1 pill orforglipron expected to launch in April, competitive pressures are likely to intensify further.

Hims, Novo Nordisk and Eli Lilly all ran advertisements during Sunday's Super Bowl promoting their weight-loss treatments.