Eli Lilly has sent cease-and-desist letters to U.S. healthcare providers in recent days demanding they stop the promotion of copycat weight-loss drugs as the supply of its brand-name medicines improves, Bloomberg News reported Wednesday.

Lilly now considers the brand-name drugs to be available and said compounded drugs from state-licensed facilities should not be sold anymore, the report added, citing a spokesperson.

The U.S. Food and Drug Administration recently listed all doses of Eli Lilly's weight-loss drug Zepbound and diabetes drug Mounjaro as available, but did not remove them from the shortage list.

The health regulator and Eli Lilly did not immediately respond to Reuters requests for comment.

The letters were sent to telehealth companies, wellness centers and medical spas, a spokesperson said, according to the report.

The report also said several brick-and-mortar clinics also received letters, according to interviews and records reviewed by Bloomberg.

The letters, signed by attorneys at Kirkland & Ellis LLP, command providers to stop the "manufacture, promotion, and/or sale" of compounded versions of Lilly's Mounjaro and Zepbound, Bloomberg said.