Novo Nordisk said it has filed lawsuits Tuesday against multiple medical spas, weight loss clinics and compounding pharmacies for allegedly selling unauthorized versions of the drugmaker's popular medicines Ozempic and Wegovy.

For months, the drugmaker has been threatening to take legal action against clinics and compounding pharmacies offering what they claim to be semaglutide — the active ingredient in both Ozempic and Wegovy — amid an ongoing shortage in the U.S. 

The lawsuits were first reported by The Wall Street Journal.

Novo Nordisk is the sole patent holder of semaglutide and does not sell the ingredient to outside entities, raising questions about what is actually being sold to consumers.

In a release Tuesday, the company said it is suing clinics and pharmacies for "false advertising, trademark infringement and/or unlawful sales of non-FDA approved compounded products claiming to contain semaglutide."

The company has initiated five lawsuits, which were submitted in federal courts in New York, Texas, Florida and Tennessee, said Novo Nordisk spokesperson Allison Schneider.

"These unlawful marketing and sales practices, including the use of Novo Nordisk trademarks in connection with these practices, have created a high risk of consumer confusion and deception as well as potential safety concerns," the company wrote in the release.

The lawsuits from Novo Nordisk mark a significant escalation in the fight against the selling of copycat versions of Ozempic and Wegovy.

A handful of states have also threatened to sue or take other legal action against compounding pharmacies that make or dispense unauthorized versions of the weight loss drugs.

Making compounded versions of commercially available drugs is permissible under special circumstances, like a shortage, according to the Food and Drug Administration.

But state regulators say they are concerned with medications that are made using semaglutide sodium salt — a cheaper and modified version of the compound that is used for scientific research but not intended for use in humans.