Amidst the war on obesity, a clear winner has emerged in the battle between the two weight loss injections. Zepbound (tirzepatide), manufactured by a Fortune 500 company Eli Lilly & Co.the best competitor Wegovy (semaglutide), a product of the Global 500 company Novo Nordiskin a recent one randomized clinical trial with support from Lilly.
After injecting the drugs weekly for almost 17 months, patients who took Zepbound lost an average of 20.2% of their body weight (50.3 pounds), while Wegs patients lost 13.7% (33.1 pounds), Lilly announced Dec. 4 news. In addition, Zepbound achieved a 47% greater relative weight loss than its competitor, and 31.6% of Zepbound patients lost at least 25% of their body weight, compared to 16.1% of Wegovy users.
“Given the increased interest in anti-obesity drugs, we conducted this study to help healthcare providers and patients make informed decisions about treatment choices,” Dr. Leonard Glasssenior vice president for global medical affairs at Lilly Cardiometabolic Healthit is stated in the press release. “Zepbound is in a class of its own as the only FDA-approved dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) anti-obesity drug, and is changing the way millions of people manage chronic disease .”
The trial included 751 US adults aged 18 and older who were either obese or overweight with at least one of the following health conditions: heart disease, high blood pressure, high cholesterolor obstructive sleep apnea. They received the maximum tolerated dose of Zepbound (10 mg or 15 mg) or Wegovy (1.7 mg or 2.4 mg) for 72 weeks. (None of the participants had diabetes; Lilly sells tirzepatide as Mounjaro to people with type 2 diabetes, doc Novo Nordisk does the same for semaglutide as Ozempic.)
The results have not yet been peer-reviewed, but Lilly indicated they will be published in a peer-reviewed journal in 2025 and presented at an unspecified medical meeting.
Lilly funded a clinical trial that, the company said, “was designed to demonstrate Zepbound’s superiority in percent change from baseline in body weight at 72 weeks compared to Wegovy.” This shouldn’t necessarily raise eyebrows, he says Ph.D. W. Scott Butschdirector of obesity medicine in Cleveland Clinic Bariatric and Metabolic Institute.
“We should always look at the source of funding as a potential study bias,” Butsch says Wealth via e-mail. “But this study was well designed and we should trust the data.”
What’s more, the trial’s results are similar to those of a study—not funded by Lilly—published earlier this year in the journal JAMA Internal Medicine, Ph.D. Holly Loftonobesity medicine specialist in NYU Langone Healthpoints out that Wealth. That study found that 42.3% of people taking tirzepatide, the generic name for Zepbound, lost at least 15% of their body weight within a year, compared with 15% of people taking semaglutide, the generic name for Wegovy.
Should I take Zepbound instead of Wegovy?
Both Zepbound and Wegovy are prescription drugs, so you should consult your doctor if you are concerned about taking one over the other. They’re also not the only weight-loss medications, and your doctor can help you determine which one might be right for you, based on your weight-loss goals and medical history.
And while the results of Lilly’s trial are promising, they shouldn’t be your only consideration when looking for a weight-loss drug, says Lofton.
“Both drugs show significant weight loss of over 10%, which can improve or alleviate many weight-related medical conditions,” says Lofton Wealth via e-mail. “Prescribers and patients should always consider the safety, efficacy and availability of a drug when deciding which drug is best for a patient.”
Butsch reiterates, “From a patient perspective, I do not think these study results will change public demand for tirzepatide, nor will it result in a drug switch. This confirms that there are currently two very effective drugs, but so many factors – price, coverage, etc. – which represent barriers to access.”
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