In a groundbreaking development, the diabetes drug Mounjaro, manufactured by Eli Lilly, has demonstrated its remarkable potential as a powerful aid for weight loss in individuals grappling with obesity or excess weight. A recent study has unveiled that, when combined with an intensive diet and exercise regimen, Mounjaro can help overweight individuals shed an average of approximately 27 kilograms (60 pounds).
The study, published in the journal Nature Medicine, found that participants who integrated Mounjaro into their weight loss journey lost a substantial amount of weight over a period of around 19 months. In contrast, a control group that followed a similar diet and exercise program but received placebo injections initially lost weight, only to regain some of it later.
Dr. Thomas Wadden, an obesity researcher and psychology professor at the University of Pennsylvania, who led the study, emphasized the significance of these findings: “This study says that if you lose weight before you start the drug, you can then add a lot more weight loss after.” The results, which were also presented at a medical conference, indicate that Eli Lilly’s Mounjaro could potentially become one of the most potent medical treatments for obesity to date, according to experts in the field.
Dr. Caroline Apovian, an expert in obesity treatment at Brigham and Women’s Hospital in Massachusetts, underscored the impact of the study, stating, “Any way you slice it, it’s a quarter of your total body weight.” This remarkable achievement comes at a time when obesity and related health concerns continue to be a global health crisis.
Mounjaro, also known by its generic name tirzepatide, was initially approved in the United States in May 2022 for the treatment of diabetes. However, it has since been used “off-label” to combat obesity, joining the increasing demand for diabetes and weight-loss medications such as Ozempic and Wegovy, produced by Novo Nordisk. All of these drugs, with monthly retail prices exceeding $900, have faced shortages for several months.
Tirzepatide functions by targeting two hormones that play a crucial role in regulating appetite and the sensation of fullness after eating, which are vital for weight management. The study, funded by Eli Lilly, enrolled approximately 800 participants who had obesity or were overweight with weight-related health complications but did not have diabetes.
After an initial three-month phase of rigorous diet and exercise, over 200 participants left the study due to insufficient weight loss or other reasons. The remaining nearly 600 individuals were randomly assigned to receive either tirzepatide or a placebo via weekly injections for approximately 16 months, with nearly 500 participants completing the study.
During the diet-and-exercise phase, both groups experienced a weight loss of about 7% of their initial body weight, equating to nearly 8 kilograms. However, those who received tirzepatide continued to lose an additional 18.4% of their initial body weight, averaging around 20 kilograms more. In contrast, those who received the placebo injections regained about 2.5% of their initial weight, equivalent to 2.7 kilograms.
The study demonstrated the remarkable efficacy of tirzepatide, with approximately 88% of participants losing 5% or more of their body weight, compared to just 17% of those in the placebo group. Impressively, nearly 29% of those taking the drug achieved a weight loss of at least a quarter of their body weight, a rate similar to that seen with bariatric surgery.
Despite these promising results, the drug did exhibit some side effects, including nausea, diarrhea, and constipation, which were reported more frequently in the tirzepatide group compared to the placebo group. These side effects were generally mild to moderate in intensity and were more likely to occur as the drug’s dosage was increased. Over 10% of individuals in the tirzepatide group discontinued the study due to side effects, in contrast to approximately 2% of those in the placebo group.
Eli Lilly is expected to release the results of another study in the near future, which the company claims shows similarly high rates of weight loss. The U.S. Food and Drug Administration has granted Eli Lilly a fast-track review of tirzepatide for obesity treatment, with the possibility of marketing the drug under a different brand name. A decision is anticipated by the end of the year, potentially marking a significant milestone in the treatment of obesity.