Zepbound (Tirzepatide) More Effective Than Wegovy for Weight Loss, Eli Lilly Trial Shows

A new clinical trial funded by Eli Lilly has found that Zepbound (tirzepatide) delivers significantly better weight loss results compared to Wegovy (semaglutide), a similar drug developed by Novo Nordisk.

What the Study Found

The SURMOUNT-5 trial, published in The New England Journal of Medicine, was a Phase 3b open-label trial involving 751 adults with obesity but without diabetes. Participants were randomized to receive either tirzepatide or semaglutide once a week.

After 72 weeks, the average weight loss was:

• 20.2% for tirzepatide (Zepbound), or approximately 50.3 pounds
• 13.7% for semaglutide (Wegovy), or about 33.1 pounds

Additionally, 32% of participants on tirzepatide lost 25% or more of their body weight, compared to 16% on semaglutide. Waist circumference and other metabolic risk factors also improved more in the tirzepatide group.

Why Tirzepatide Outperforms Semaglutide

Experts believe tirzepatide’s dual mechanism of action gives it the edge. It targets both the GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) receptors, while semaglutide targets only GLP-1.

Dr. Raj Dasgupta, a medical advisor not involved in the trial, explained that the second pathway enhances appetite control and energy metabolism, resulting in more significant fat loss for Zepbound users.

Safety and Side Effects

Both drugs were generally well tolerated. However:

• Semaglutide users reported more dropouts due to gastrointestinal side effects like nausea and diarrhea.
• Tirzepatide users had more injection-site reactions, though these were usually mild.

Most side effects were temporary and occurred during dose adjustments.

Real-World Impact and Access Challenges

While Zepbound shows promise, cost and insurance coverage remain major barriers. Dr. Austin Shuxiao noted that tirzepatide is often harder to get approved for patients with limited insurance plans.

“Insurance will dictate patients’ access to medication, not just medical preference,” he said. Nonetheless, Shuxiao believes that GLP-1 medications like tirzepatide could be transformative in obesity treatment if long-term safety is confirmed.

Takeaway for Patients

For individuals struggling with obesity, these results offer new hope. Tirzepatide provides an alternative for those who don’t respond well to semaglutide or who experience undesirable side effects.

However, both physicians and researchers emphasize that no drug is a magic solution. Best outcomes still depend on a holistic approach that includes:

• Healthy nutrition
• Consistent physical activity
• Quality sleep
• Stress management

Conclusion

Tirzepatide (Zepbound) has emerged as a leading contender in obesity treatment, offering greater weight loss and metabolic improvements than semaglutide. With further research and improved insurance access, this dual-acting medication could become a cornerstone in the fight against obesity.