Amidst the war on obesity, a clear winner has emerged in the battle between two injectable weight loss drugs. Zepbound (tirzepatide) is a Fortune 500 company Eli Lilly & Co.beat competitor Wegovy (semaglutide), a Global 500 product Nova Nordiskrecently a randomized clinical trial supported by Lilly.
After weekly administration of the medication for nearly 17 months, patients who took Zepbound lost an average of 20.2% body weight (50.3 pounds). Vegs Patients lost 13.7% (33.1 pounds), Lilly announced Dec. 4 news release. In addition, Zepbound resulted in 47% greater relative weight loss compared to 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 obesity medications, we conducted this study to help healthcare professionals and patients make informed decisions about treatment options,” Dr. Leonard Glasssenior vice president of global medical affairs Lilly Cardiometabolic Healthsays the press release. “Zepbound is in a class of its own as the only FDA-approved anti-obesity drug with a dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptor agonist, and it is changing the way millions of people manage this chronic disease.” .
The trial involved 751 American adults aged 18 and older who were either obese or overweight with at least one of the following 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 Munjaro people with type 2 diabetes Nova Nordisk does the same for semaglutide as Azempik.)
The results have not yet been peer-reviewed, but Lilly said they will be published in a peer-reviewed journal in 2025 and presented at an unspecified medical meeting.
Lilly funded the clinical trial, which the company said was designed to “demonstrate the superiority of Zepbound in percentage changes in body weight from baseline at 72 weeks compared to Wegovy.” It shouldn’t necessarily raise eyebrows, he says Dr. V. Scott Butchdirector of obesity medicine at Cleveland Clinic Bariatric and Metabolic Institute.
“We always have to consider the source of funding as a potential study bias,” says Butch Fortune by e-mail. “But this study was well designed, and we have to trust the data.”
What’s more, the results of the trial are similar to those of a non-Lilly-funded study published earlier this year in the journal JAMA Internal Medicine, Dr. Holly Loftonspecialist in obesity medicine at NYU Langone Healthpoints to Fortune. This study found that 42.3% of people who took tirezapatide, the generic name of Zepbound, lost at least 15% of their body weight over a year, compared with 15% of people who took semaglutide, the generic name of Wegovy.
Should I take Zepbound instead of Wegovy?
Both Zepbound and Wegovy are prescription medications, so you should check with your doctor if you are unsure about taking one over the other. These aren’t the only weight loss medications either, and your doctor can help you determine which ones might be right for you based on your weight loss goals and medical history.
And while Lilly’s trial results are promising, they shouldn’t be the only consideration when asking for a weight-loss drug, Lofton says.
“Both drugs show significant weight loss of more than 10%, which can improve or alleviate many weight-related conditions,” Lofton says. Fortune by e-mail. “Prescribers and patients should always consider the safety, efficacy, and availability of medications when deciding which drug is best for a patient.”
Butch reiterates, “From a patient perspective, I don’t think these study results will change public demand for tirepatide or lead to a change in medication. This confirms that there are currently two very effective drugs, but there are so many factors – cost, coverage, etc. – which are barriers to access.”
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