Mounjaro vs Wegovy: New Clinical Trial Finds Mounjaro Superior for Weight Loss

In a landmark head-to-head clinical trial, Eli Lilly’s tirzepatide-based injection Mounjaro has been shown to be “superior” to Novo Nordisk’s semaglutide-based Wegovy for the treatment of obesity.

The trial, published following rigorous research conducted between April 2023 and November 2024, compared two groups of patients living with obesity but without type 2 diabetes. Participants were given either tirzepatide (10 mg or 15 mg) or semaglutide (1.7 mg or 2.4 mg)—both of which are part of the GLP-1 receptor agonist (GLP-1RA) class of medications.

How the Two Weight Loss Medications Compare

While both treatments led to meaningful weight loss, tirzepatide outperformed semaglutide significantly:

• Tirzepatide (Mounjaro) users lost an average of 22.8 kg, which is a 20.2% reduction in body weight after 72 weeks.

• Semaglutide (Wegovy) users saw a 13.7% reduction, with an average loss of 15 kg over the same period.

In addition, a greater percentage of Mounjaro users achieved key weight loss milestones, including reductions of at least 10%, 15%, 20%, and 25% of their body weight.

Women in both treatment arms experienced more significant weight loss than men—around 6% more on average, the data revealed.

About the Trial Participants

To take part in the study, patients needed to have:

• A BMI of 30 or more, or BMI of 27+ with an obesity-related condition such as high blood pressure or cardiovascular disease

• A documented history of at least one unsuccessful dietary attempt at weight loss

The trial included 750 participants and was conducted over an 18-month period, with careful dose titration for both medications.

Dosing Regimens Compared

The trial followed each medication's recommended dose escalation:

• Tirzepatide (Mounjaro): Started at 2.5 mg weekly, increased every 4 weeks by 2.5 mg to a maximum of 10 mg or 15 mg.

• Semaglutide (Wegovy): Started at 0.25 mg weekly, escalating every 4 weeks through 0.5 mg, 1.0 mg, 1.7 mg, up to a max of 2.4 mg.

A New Generation of Obesity Treatment

The researchers concluded that tirzepatide represents a new generation of highly effective medications for managing obesity in people without diabetes. The results of this trial may shift clinical prescribing preferences and patient demand.

This comes amid reports that Mounjaro has already overtaken Wegovy in popularity according to recent Ready Health prescribing data from the first half of 2025

What Does This Mean for Patients?

If you're currently exploring medical options for weight loss, this study adds weight to the argument that Mounjaro may offer more powerful results than Wegovy, especially for those without diabetes. However, it's important to consider factors such as tolerability, cost, and individual health conditions before choosing a treatment.

Ready Health Clinic in Standish offers expert consultation and prescription services for GLP-1 medications like Mounjaro and Wegovy. Our weight management plans are overseen by qualified medical professionals and tailored to your personal goals and health profile.

📞 Book your consultation today to discuss your eligibility and start your journey to sustainable weight loss.