Mounjaro vs. Ozempic: The Battle of Weight Loss Jabs

The world of weight loss medications recently witnessed a significant head-to-head study between two major contenders: Mounjaro and Ozempic. Conducted by American scientists, this extensive study involved over 18,000 participants and aimed to determine which drug proved more effective in aiding weight loss. Here's a detailed look at the findings and implications of this groundbreaking research.

Nutrient-dense foods are rich in vitamins, minerals and other nutrients important to our health.

Study Design and Participants

The study, published in JAMA Internal Medicine, evaluated the effectiveness of two drugs, Mounjaro and Ozempic, both of which work by mimicking hormones that induce a feeling of fullness. 


The study cohort included adults with type 2 diabetes who took one of the weekly injections for up to a year. Participants were evenly divided, with half receiving Mounjaro (tirzepatide) and the other half receiving Ozempic (semaglutide). 


The initial average weights of participants were similar, with the Mounjaro group averaging 110 kg and the Ozempic group slightly lighter at 109 kg.

Key Findings

The results demonstrated a clear victory for Mounjaro. Patients on Mounjaro were 224% more likely to lose approximately a sixth of their body weight compared to those on Ozempic. On average, Mounjaro users lost up to 7% more weight than those using Ozempic.


Specific weight loss milestones also favored Mounjaro:

  • 5% Weight Loss: 82% of Mounjaro patients achieved this goal, compared to 66% of Ozempic patients.
  • 10% Weight Loss: About 60% of Mounjaro patients reached this milestone, versus just under 40% for Ozempic.
  • 15% Weight Loss: 42% of Mounjaro users hit this target, compared to 18% of Ozempic users.

These statistics translate to a 76% increased chance of achieving 5% weight loss, an 84% increased chance of reaching 10% weight loss, and an impressive 224% increased likelihood of losing 15% or more body weight with Mounjaro.

Time-based Weight Loss

Over different intervals (three months, six months, and one year), Mounjaro consistently led in average weight loss. Participants lost 2.4%, 4.3%, and 6.9% more weight at these intervals compared to those on Ozempic.

Side Effects and Safety

Importantly, the study found no significant difference in the occurrence of gastrointestinal side effects, such as diarrhea and vomiting, between the two groups. This suggests that the superior weight loss benefits of Mounjaro do not come at the cost of increased adverse effects.

Conclusions and Future Research

The study concluded that tirzepatide (Mounjaro) significantly outperformed semaglutide (Ozempic) in achieving clinically meaningful weight loss in adults with type 2 diabetes. However, researchers noted that their findings were specific to patients with type 2 diabetes. Both drugs are also available to obese individuals without diabetes, with semaglutide marketed as Wegovy for this purpose.


Further research is expected, particularly studies focusing solely on obese patients without diabetes, to validate these findings. Such a study is currently underway and expected to publish results later this year.

Broader Implications

The popularity and effectiveness of weight loss jabs like Mounjaro and Ozempic have profound implications. With obesity rates soaring—26% of adults in England and 41.9% in the US are classified as obese—these medications offer a promising tool to combat this public health crisis.


The potential benefits of these drugs extend beyond weight loss, including reducing risks of heart attacks, strokes, and other health conditions. As such, there is ongoing debate about whether these medications should be proactively prescribed to curb cardiovascular diseases.


In summary, Mounjaro has emerged as the front-runner in the battle of weight loss jabs, showing superior efficacy over Ozempic. As research continues and usage broadens, these findings could significantly impact obesity treatment strategies worldwide.

Balance Macronutrients

Our expert team is here to help. It's FREE with your CheqUp prescription

Don't forget - your CheqUp prescription comes with free access to our expert team who can advise on topics including exercise, Mounjaro side effects, nutrition and generally act as a sounding board for your weight loss journey. 

Book your appointment today

Findings summarised from the original study published in JAMA Internal Medicine, July 2024.

"Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity"


Read our customer reviews

Published: 28th June 2024