A new meta-analysis from the University of Georgia has provided what its authors say is a comprehensive comparison of three popular GLP-1 medications for weight loss, finding that tirzepatide (sold as Zepbound and Mounjaro) produced the greatest results among non-diabetic patients.
The study examined weight loss outcomes across 14,000 patients taking one of three medications: tirzepatide, semaglutide (Wegovy, Ozempic), or liraglutide (Saxenda, Victoza). Researchers at UGA's College of Pharmacy conducted the review to determine which drug provided the most effective weight loss without elevated side effects.
What the Left Is Saying
Progressive health policy advocates have pointed to studies like this one as evidence that newer GLP-1 medications should be more widely accessible. Groups including Families USA and certain Democratic lawmakers have argued that Medicare and other federal health programs should cover these drugs, particularly for patients with obesity-related conditions. Senator Bernie Sanders of Vermont has repeatedly called for lower drug prices, arguing that pharmaceutical companies profit excessively before treatments become affordable to those who need them.
"When you have a medication that produces 20% body weight loss, that's a game-changer for public health," said Dr. Ashish Jha, former White House COVID-19 response coordinator, in comments cited by progressive health policy observers. "But it only matters if people can actually afford to take it."
What the Right Is Saying
Conservative healthcare analysts and Republican lawmakers have emphasized that drug development requires substantial investment and that robust patent protections incentivize the innovation that produces breakthrough treatments. The Pharmaceutical Research and Manufacturers of America (PhRMA) has argued that price controls or mandatory negotiations could discourage companies from pursuing difficult, expensive research.
"These results represent exactly what our free-market system is designed to produce—competition that drives medical progress," said a spokesperson for the American Enterprise Institute's health policy team. "The solution isn't government price-setting, it's ensuring more Americans have choices in their healthcare."
What the Numbers Show
According to the UGA meta-analysis published this week, weight loss results varied significantly by medication: tirzepatide users lost more than 20% of their starting body weight; semaglutide users lost approximately 15%; and liraglutide users lost roughly 8%. All three medications work by mimicking a hormone that lowers blood sugar, slows digestion, and signals satiety to the brain.
The study noted a key pharmacological difference: while Wegovy and Saxenda target only GLP-1 receptors, Zepbound is classified as a dual agonist, targeting both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors. Lead author Pooja Galah, a Ph.D. student at the UGA College of Pharmacy, stated that side effects including nausea and gastrointestinal issues did not significantly differ between medications.
The research did not examine outcomes after patients discontinued use, though other studies have documented weight regain following cessation of GLP-1 therapies. The analysis also did not distinguish between injectable and newer oral formulations, which clinical trials suggest are somewhat less effective than their injectable counterparts.
The Bottom Line
The meta-analysis adds to a growing body of evidence that dual-agonist medications like tirzepatide may offer superior weight loss outcomes compared to single-receptor GLP-1 drugs. However, cost remains a significant factor: Zepbound and Wegovy list for approximately $1,000 per month without insurance coverage.
Policymakers in both parties have shown interest in GLP-1 drug pricing as these medications become more widely prescribed. The Trump administration has signaled interest in allowing Medicare to negotiate prices for certain obesity treatments, though details remain under discussion. What happens with federal drug pricing policy could significantly affect how broadly these effective but expensive treatments reach American patients.