New Version of Diabetes Drug Mounjaro Approved for Weight Loss

An updated version of a popular diabetes drug has joined the ranks of others currently sweeping the nation as the next weight loss miracle. 

The U.S. Food and Drug Administration (FDA) announced Nov. 8 that Mounjaro, a diabetes drug made by pharma giant Eli Lilly, will now be available for weight loss in a higher dosage called Zepbound. Studies show that the chief ingredient in Mounjaro and Zepbound, tirzepatide, may be more effective than semaglutide in Wegovy. Both are administered via weekly injection.

Wegovy is a high-dose version of Novo Nordisk’s Ozempic diabetes drug.

Mounjaro and Wegovy have gone viral on social media, with celebrities showing off their weight loss results on TikTok. 

Like Wegovy, the FDA-approved Zepbound is for people with a body mass index (BMI) of 30 or higher, along with those who are overweight with a related health problem such as diabetes or high blood pressure.

Tirzepatide and semaglutide mimic the hormones that kick in after people eat, slowing the emptying of their stomachs and making them feel fuller for longer. While both drugs imitate the key hormone GLP-1 (glucagon-like peptide 1), tirzepatide mimics a second hormone, GIP (glucose-dependent insulinotropic polypeptide). Experts believe these two imitations work together, making tirzepatide significantly more effective than semaglutide.

The FDA issued its approval for Zepbound based on two major studies.

In the first – which was sponsored by Lilly – more than 2,500 participants, some with diabetes and some not, were given varying strengths of Zepbound (approximately 1,000 received placebo shots). Participants without diabetes who received the highest strength lost about 41 pounds compared to the placebo; people with diabetes averaged nearly 27 pounds.

Overall, Wegovy helped people lose about 34 pounds.

In a second study, participants who combined Zepbound with diet and exercise lost up to 60 pounds or 25 percent of their weight, making it the most effective weight loss drug in history – comparable, even to surgery.

Both active ingredients, say experts, induce more than enough weight loss to reduce cardiovascular health risks significantly.  

However, patients must take them indefinitely; otherwise, up to two-thirds of the weight will return. 

For people with type 2 diabetes, tirzepatide also lowers the average amount of sugar in their blood. Diabetics and others who need the drug to stay healthy are at risk from a continuing shortage of tirzepatide, semaglutide, and a third drug, dulaglutide. 

Allowing their blood sugar levels to get too high is dangerous and sometimes fatal for diabetics, but pharmacy shelves across the country have been empty for months as more people utilize the drug for weight loss.

Eli Lilly said in a statement that they plan to double the manufacturer’s GLP-1 capacity by year’s end to combat the shortage.

Because most insurance companies do not cover weight management programs unless accompanied by a health condition, Zepbound will cost patients an expected $1,100 monthly.

A 2021 study comparing semaglutide to tirzepatide found that the latter resulted in greater weight loss and reduced blood sugar than its competitor.

However, with higher efficacy comes a higher risk of dangerous side effects.

Users often experience nausea, vomiting, diarrhea, and stomach pain; more severe cases can lead to pancreatitis, gastrointestinal bleeding, hypoglycemia, renal failure, gallbladder disease, thyroid tumors, and stomach paralysis. These more serious risks, unlike the milder common side effects, are not listed on the drug’s packaging.

Stomach paralysis, or gastroparesis, occurs when stomach muscles don’t contract how they should, keeping food trapped in the stomach and unable to pass through the digestive tract. Complications include malnutrition, dehydration, unstable blood sugar changes, and life-threatening intestinal blockage. 

In August 2023, a Louisiana woman with Type 2 diabetes filed a lawsuit against Eli Lilly and Novo Nordisk for failure to warn consumers of the risk of gastroparesis. After using Ozempic and Mounjaro, she endured severe stomach pain, gastrointestinal burning, and so much vomiting that she lost teeth. 

The following month, the FDA ordered Novo Nordisk to add the risk of ileus, the medical term for lack of intestinal movement leading to blockage, to its warning label. 

Increased reports of diabetes drugs causing gastroparesis around the world are expected to produce more diabetes weight loss drug lawsuits in the coming months.