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.

Hims & Hers Health shares tumbled nearly 35% Monday after Novo Nordisk said it is pulling out of its partnership with the digital pharmacy, citing "illegal" and "deceptive" practices.