Pharmacist Mark Mikhael has lost 50 pounds over the past 12 months. He no longer has diabetes and finds himself “at my ideal body weight,” with his cholesterol below 200 for the first time in 20 years. “I feel fantastic,” he said.

Like millions of others, Mikhael credits the new class of weight loss drugs. But he isn’t using brand-name Wegovy or Zepbound. Mikhael, CEO of Orlando, Florida-based Olympia Pharmaceuticals, has been getting by with his own supply: injecting himself with copies of the drugs formulated by his company.

He’s far from alone. Mikhael and other industry officials estimate that several large compounding pharmacies like his are provisioning up to 2 million American patients with regular doses of semaglutide, the scientific name for Novo Nordisk’s Wegovy, Ozempic, and Rybelsus formulations, or tirzepatide, the active ingredient in Eli Lilly’s Zepbound and Mounjaro.