FDA Restricts Compounded GLP-1 Drugs as Weight-Loss Pill Race Heats Up

The U.S. Food and Drug Administration (FDA) is moving to exclude semaglutide, tirzepatide and liraglutide — the active ingredients in popular GLP-1 weight-loss and diabetes drugs including Wegovy, Ozempic, Zepbound and Mounjaro — from its 503B bulks list. The agency said the drugs are no longer on its drug shortage list, and after evaluating the proposed clinical need, a review of the evidence did not support a medical need for most instances of the drugs being administered in bulk. Regulators are accepting public comments through June 29 before making a final determination.

“When FDA-approved drugs are available, outsourcing facilities cannot lawfully compound using bulk drug substances unless there is a clear clinical need,” the FDA commissioner said. The action is aimed at improving safety and stopping widespread, unregulated versions of these high-demand weight-loss and diabetes drugs from being sold online by third-party distributors. It will not affect traditional prescriptions or direct distribution from the companies.

The weight-loss drug market is booming, with biotech firms racing to capture a slice of a fast-growing sector dominated by Novo Nordisk and Eli Lilly. The British health regulator approved a pill version of Novo’s blockbuster obesity drug Wegovy in June, and the European Medicines Agency recommended approval of the Wegovy pill in May. Lilly won U.S. approval for its weight-loss pill orforglipron, branded as Foundayo, in April, more than three months after Novo secured clearance for the Wegovy pill, as the multibillion-dollar market shifts toward oral therapies. Eli Lilly built a $1.5 billion stockpile of the pill in advance of FDA approval.

Novo Nordisk is developing a next-generation injection called amycretin and CagriSema, touted as a potent successor to Wegovy. Amycretin, which targets GLP-1 and amylin hormones, showed statistically significant weight loss of up to 14.5% at 36 weeks in patients with type 2 diabetes in a mid-stage study. CagriSema helped overweight patients cut their weight by 22.7% in one of two late-stage trials, below Novo’s expectations of 25%; Novo filed a marketing application for potential U.S. approval of CagriSema in December. Novo also struck a licensing deal worth up to $2 billion with China-based United Laboratories for its “triple-G” weight-loss drug candidate that targets three hormones.

Through a buyout last year, Pfizer gained access to Metsera’s obesity drugs, including MET-097i, a GLP-1 therapy designed for a once-monthly injection. The drug, now known as PF-3944 and called berobenatide, led to up to 12.3% weight loss in patients without diabetes, with no plateau observed at week 28, when given as a monthly injection. It had a mean nausea rate of about 38% and a mean vomiting rate of about 23.3%, a side-effect profile similar to Novo Nordisk’s weekly Wegovy injection, according to data presented at a medical meeting in June. Pfizer is targeting 2028 for its first approval in the weight-loss drug market and plans to advance more than 20 clinical trials involving obesity treatments this year.

Separately, Novo Nordisk said it is suing Eli Lilly over “false and materially misleading” adverts for Lilly’s rival weight-loss and anti-diabetes treatments. Novo complained that Lilly “intentionally selected outdated studies” that compared Lilly’s highest doses against lower doses of Novo’s medicines, and that the ads “deceptively presented those results as proof of broad, product-level superiority while burying or omitting critical clinical context.” The ad campaign was “aired during recent, widely viewed global sporting broadcasts and on TikTok and Facebook.” Eli Lilly responded that the trial underpinning its advertising, Surmount-5, is “the only direct, head-to-head randomised clinical trial comparing tirzepatide and semaglutide in the context of weight management,” and said it firmly stands by its advertising campaign.

Anti-obesity treatments mimic a hormone secreted by the intestines, GLP-1, and can be used for weight loss and/or to treat type 2 diabetes. The competing drugs are a financial windfall for each of the pharmaceutical giants, and the weight-loss sector is expected to generate about $100 billion in annual sales in the next decade.