Eli Lilly Warns About Potential Health Risks From Mounjaro, Zepbound Counterfeit Versions

Drug maker plans to pursue legal remedies against compounding pharmacies, medical spas and other entities that claim to sell generic versions of Mounjaro and Zepbound.

The makers of the diabetes and weight loss drugs Mounjaro and Zepbound are warning that fake and compounded versions of the medications carry an increased risk health risks and should not be used for cosmetic weight loss.

Eli Lilly published an open letter on March 7, indicating that unapproved uses of the active ingredient of Mounjaro and Zepbound, tirzepatide, can lead to bacterial infections, may contain impurities, and warns some products claiming to be those drugs have completely different chemical structures.

Mounjaro is a popular diabetes treatment that was introduced by Eli Lilly in 2022, as part of a new generation of treatments for diabetes, which are also effective for weight loss. It is part of the same class of drugs as Ozempic (semaglutide), and both medications have been widely prescribed “off-label” as diet drugs, given the positive effect they have helping to reduce hunger, decease food intake and promote feelings of fullness.

Last year, the U.S. Food and Drug Administration (FDA) announced the approval of Zepbound, containing the same active ingredient, tirzepatide, which is now specifically authorized for chronic weight management in adults with obesity.

Amid the increasing popularity of the drugs, a number of former users are now pursuing Mounjaro lawsuits, Ozempic lawsuits and Wegovy lawsuits against the manufacturers, each raising similar allegations that the drug labels fail to adequately warn about the risk of severe and long-lasting side effects, including a form of severe stomach paralysis, known as gastroparesis. However, demand for the drugs has still resulted in widespread shortages, causing many compounding pharmacies to offer generic versions of the treatment.

In its letter, Eli Lilly warns against the use of either drug as simply an easy means of losing weight.

“Mounjaro and Zepbound are indicated for the treatment of serious diseases; they are not approved for – and should not be used for –cosmetic weight loss,” the letter states. “Lilly does not promote or encourage the use of Mounjaro, Zepbound, or any Lilly medicines outside of a medicine’s FDA-approved indication.”

The company also noted that the two drugs are not approved for use by children under 18 years of age.

Fake and Compounded Mounjaro, Zepbound Risks

In addition, Lilly notes that it is the only lawful supplier of tirzepatide in the U.S., and does not sell or provide the ingredient to compounding pharmacies, warning that patients taking any product only referred to as tirzepatide, and not sold under the brand names of Mounjaro or Zepbound, are not taking an approved product.

The company warns that it has discovered products claiming to be compounded tirzepatide have been found to contain bacteria, high levels of impurities, different chemical structures, and in one case discovered that a product being sold as tirzepatide contained only sugar alcohol.

The letter indicates the company is pursuing “legal remedies” against compounding pharmacies and counterfeiters at certain medical spas, and wellness centers who falsely claim their products are Mounjaro, Zepbound, or an approved FDA alternative.

The warning comes after a report published by Reuters in January, which found that at least three cases of hypoglycemia has been linked to counterfeit Ozempic products.

The American Poison Centers indicates that it received a total of 3,316 reports involving Ozempic poisoning last year.

Mounjaro, Zepbound Stomach Paralysis

However, a number of concerns have arisen over the last year about the risks of taking the actual, approved versions of the drugs, as well as others in the class of medications known as  glucagon-like peptide-1 receptor agonists (GLP-1 RAs), which also include Ozempic and Wegovy.

In July 2023, the American Society of Anesthesiologists (ASA) issued a warning about using Ozempic and Wegovy before surgery, indicating that the lack of gastric emptying linked to the drugs could put patients at risk of vomiting and aspiration while under the effects of anesthesia. Similar side effects are linked to Mounjaro, which could also pose a problem during surgical anesthesia.

In 2017, researchers with the Mayo Clinic conducted a study involving a similar diabetes medication known as Victoza, which found that the drug caused significantly slower digestion in users, taking about 70 minutes for half the food they ate to leave their stomachs, compared to four minutes for people who did not take the drug. However, the study found that people’s bodies tended to adjust over time.

In September, the FDA issued new label warnings for Ozempic, indicating that it can increase the risk of intestinal blockages. The warning links Ozempic to a condition known as ileus, which can cause abdominal cramps, bloating, nausea, vomiting, constipation, difficulty passing gas and difficulty eating.