Unapproved, compounded versions of a popular diabetes and weight-loss drug are being sold in Canada, the Ozempic maker said, amid a warning about dosing errors that have resulted in some people being hospitalized in the United States.

Novo Nordisk told Global News on Monday that it has filed a complaint with Health Canada regarding the promotion and sale of compounded semaglutide – which is a key ingredient in both Ozempic and Wegovy – in Canada.

“We are aware that several compounding pharmacies, weight loss clinics, and medical spas are purporting to sell or offer unapproved compounded semaglutide products both in Canada and the U.S.,” a spokesperson for Novo Nordisk Canada said in an emailed statement.

“Patients should be aware that Novo Nordisk is the only company in Canada with Health Canada-approved products containing semaglutide and the only company in the U.S. with FDA-approved products containing semaglutide, identified under the trade names Ozempic, Rybelsus and Wegovy.”

Compounding is when pharmacies or other practitioners have the substances needed to mix and prepare specialty medications, and do so. It was frequently used in Canada by pharmacies during the COVID-19 pandemic when manufactured supplies of children’s pain medications were in short supply, but the pharmaceutical components to mix those medications were still available in some pharmacies.

It is only meant to be done in cases where there is limited supply of a medication “and should not be done solely for economic reasons for the healthcare professionals,” according to Health Canada guidelines on compounding.

On Friday, the U.S. Food and Drug Administration (FDA) issued an alert, warning doctors and patients about dosing errors involving compounded semaglutide injectable products that were dispensed in multiple-dose vials.

The health regulator said it had received reports of adverse events, with some requiring hospitalization, that may be related to overdoses due to patients incorrectly self-administering the compounded drug and health-care providers miscalculating doses.

Because of the dosing errors, patients mistakenly took five to 20 times more than the intended dose, the FDA said.

The Novo Nordisk spokesperson said the FDA alert does not relate to the company’s products, Ozempic or Wegovy, but pertains to compounded semaglutide products, which are not approved in Canada nor in the U.S.

Novo Nordisk has filed 21 lawsuits in the U.S. against medical spas, weight-loss clinics and compounding pharmacies engaging in “unlawful” marketing and sales of compounded drugs claiming to contain semaglutide, the spokesperson said.

Global News reached out to Health Canada about the FDA warning and the dosing errors, but did not receive a response by the time of publication.

Among the adverse events reported in the U.S., some patients experienced nausea, vomiting, abdominal pain, fainting, headache, migraine, dehydration, acute pancreatitis and gallstones.

Semaglutide, the key ingredient in Wegovy and Ozempic, belongs to the GLP-1 class of drugs, which work by helping control blood sugar levels and triggering a feeling of fullness.

The FDA flagged the higher risk to patients from the use of compounded drugs, which may contain additional ingredients, and may contribute to potential medication errors. Compounded drugs are not assessed by the FDA for safety, effectiveness or quality, the regulator said.

“Compounded drugs should only be used to meet a patient’s needs if the patient’s medical needs cannot be met by an available FDA-approved drug,” the FDA said.

It urged health-care providers and compounders to provide the appropriate syringe size and counsel patients on how to measure the dose.

Novo Nordisk’s Wegovy is available as single-dose pre-filled pens that deliver a preset dose for once-weekly dosing, while Ozempic is available as multiple-dose pre-filled pens for single-patient use, designed for once-weekly dosing.

In recent years, Canada, like other countries, has seen a high demand for medications like Ozempic, which is primarily approved for the treatment of Type 2 diabetes but has been used off-label for weight loss.

Wegovy, an on-label weight loss medication containing the same drug as Ozempic but at a higher formulation and made by the same manufacturer, also recently became available to Canadians.

The World Health Organization (WHO) warned last month about fake batches of Ozempic detected in some countries.

Health Canada told Global News in June that there had been no reports or complaints of counterfeit Ozempic in the country.

— with files from Reuters.