The fortune of the San Francisco-based telehealth company’s cofounder and chief executive, Andrew Dudum, crumbled by more than $400 million on Monday.

Novo Nordisk had been providing Hims & Hers with the FDA-approved Wegovy, an injectable semaglutide used for weight loss since late April in order to transition patients off compounded drugs, or off-label versions of the medication, according to the news release.

Novo Nordisk alleged that Hims & Hers is putting patient safety at risk by selling compounded versions of Wegovy. Novo's ending of its deal with Hims & Hers jeopardizes the healthcare platform's goal to lead the weight loss market.