FDA Has Seized 'Thousands' of Fake Units of Ozempic Amid Reported Cases of 'Adverse Reactions' in Patients The FDA says it's received reports of five known cases of patients having adverse reactions to the counterfeit drugs.

Those looking to slim down before the New Year might want to heed an important warning.

On Thursday, the FDA said that it had seized "thousands of units" of counterfeit Ozempic, a semaglutide injectable used as a weight loss drug, which have made their way to pharmacies and suppliers.

The agency says that five people have been affected by the counterfeit drugs so far but that their conditions have not been serious, and their symptoms are "consistent with known common adverse reactions" to authentic Ozempic, including nausea, vomiting and diarrhea.

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The FDA warned that not only is the Ozempic substance itself counterfeit, but the drug information, label, carton and needle used for the injection are also counterfeit, noting that there's no way to confirm that the needles are sterile.

Patients and pharmacies are encouraged to purchase the substance only through distributors authorized by Novo Nordisk, Ozempic's manufacturer.

"FDA takes reports of possible counterfeit products seriously and works closely with other federal agencies and the private sector to help protect the nation's drug supply," the agency wrote in a release. "FDA's investigation is ongoing, and the agency is working with Novo Nordisk to identify, investigate, and remove further suspected counterfeit semaglutide injectable products found in the U.S."

In June, Novo Nordisk filed lawsuits against five med spas and wellness clinics in four U.S. states for allegedly selling counterfeit Ozempic and Wegovy, another weight loss drug.

Related: Novo Nordisk, the Maker of Ozempic, Is Suing Spas and Clinics For Allegedly Selling Knockoffs

"Our priority is to ensure that patients have a safe and positive experience with our FDA-approved semaglutide medicines, and these actions are a direct reflection of that focus," Doug Langa, president of Novo Nordisk, said in a company release at the time. "We believe it's important to provide additional tools and education to support the proper use of our approved semaglutide products and create broad public awareness regarding the difference between our FDA-approved medicines and other products being labeled as semaglutide."

Those who believe they may have been sold counterfeit medication are encouraged to report it to the FDA here.