Retatrutide (triple agonist) achieves equivalent weight loss to dual agonists but excels at extreme weight loss targets | Research

The takeaway

Bayesian NMA of 19 RCTs (29,506 adults) shows retatrutide and dual agonists achieve equivalent mean weight loss (~11 kg) surpassing GLP-1RAs (~9 kg), but retatrutide has the highest ≥15% weight loss odds (OR 54.6) and the highest adverse event risk.

OR 54.6 for ≥15% weight loss
Retatrutide (triple GLP-1/GIP/glucagon agonist) achieves extreme weight loss targets 54.6x more than placebo—far exceeding single and dual agonists

What the researchers found

Mean weight loss: retatrutide ~11 kg, dual agonists ~11 kg, GLP-1RAs ~9 kg. ≥15% weight loss OR: retatrutide 54.6, dual 16.4, GLP-1RA 9.0. T2DM reduced loss by 4-5 kg. Retatrutide: highest AE risk. Female/high-BMI: better outcomes.

Why it matters

This is the first comprehensive NMA comparing all incretin-based weight loss drug classes. It establishes the efficacy hierarchy and identifies which patients respond best to each class.

How the study worked

Systematic review and Bayesian NMA of 19 RCTs (29,506 adults, BMI ≥25). Agents: liraglutide, semaglutide, survodutide, tirzepatide, retatrutide vs placebo. Outcomes at ≥36 weeks. Subgroup analyses by diabetes, sex, age, BMI.

What this study cannot tell us

Bayesian NMA has inherent assumptions. Retatrutide data limited (fewer trials). Head-to-head comparisons sparse. Different trial durations and populations.

How to read the evidence

Bayesian NMA of 19 RCTs with 29,506 participants. High-quality evidence synthesis. Retatrutide evidence still limited compared to established agents.

When this study was published

Published in 2025.

The bigger picture

The obesity drug landscape now has three tiers of incretin-based therapy: single, dual, and triple agonists. This hierarchy enables personalized selection—more potent agents for patients needing extreme weight loss, balanced options for those prioritizing tolerability.

Questions still open

When will retatrutide receive regulatory approval?
Can retatrutide's higher AE risk be managed with dose optimization?
Will quadruple agonists emerge as the next tier?

Common questions

What is retatrutide and how is it different?

Retatrutide activates three hormone receptors simultaneously: GLP-1, GIP, and glucagon. This "triple agonist" approach produces more extreme weight loss than drugs targeting one (semaglutide) or two (tirzepatide) receptors, but also comes with more side effects.

Which weight loss drug should I choose?

It depends on your goals and tolerance: GLP-1 agonists like semaglutide (~9 kg loss) for moderate weight loss with established safety; dual agonists like tirzepatide (~11 kg) for greater loss with a good safety balance; retatrutide (~11 kg mean but highest extreme loss rates) for ambitious targets, accepting higher side effect risk.

Read the original research

Efficacy and Safety of GLP-1 Receptor Agonists, Dual Agonists, and Retatrutide for Weight Loss in Adults With Overweight or Obesity: A Bayesian NMA.

Obesity (Silver Spring, Md.), 33(11), 2046-2054

View on PubMed ↗Publisher’s paper ↗

Citation

Sinha, Binayak; Ghosal, Samit. (2025). Efficacy and Safety of GLP-1 Receptor Agonists, Dual Agonists, and Retatrutide for Weight Loss in Adults With Overweight or Obesity: A Bayesian NMA.. Obesity (Silver Spring, Md.), 33(11), 2046-2054. https://doi.org/10.1002/oby.24360