Retatrutide: The Triple Agonist Peptide Targeting GLP-1, GIP, and Glucagon Receptors | Research

The takeaway

Review examines retatrutide, the first triple GLP-1/GIP/glucagon receptor agonist, which achieved up to 24% weight loss in trials and represents the next frontier of metabolic peptide therapy.

~24% weight loss
Retatrutide triple agonist approaches bariatric surgery-level weight loss through simultaneous GLP-1, GIP, and glucagon receptor activation

What the researchers found

Retatrutide achieved up to ~24% weight loss as a triple GLP-1/GIP/glucagon agonist, with acceptable safety and metabolic benefits beyond what dual agonists provide.

Why it matters

24% weight loss approaches bariatric surgery results without surgery. If retatrutide proves safe in larger trials, it could become the most effective non-surgical obesity treatment ever developed.

The numbers in context

Databases searched through May 2024. Specific weight loss percentages and number of included trials were analyzed but not detailed in available abstract.

How the study worked

Review of retatrutide clinical trial data, triple receptor mechanism, efficacy and safety outcomes.

Who was studied

Obese patients with or without diabetes across randomized controlled trials

What this study cannot tell us

Phase 2 data showed the 24% weight loss; phase 3 results still pending. GI side effects may be more common with triple agonism. Glucagon activation raises theoretical concerns about blood sugar in some patients. Long-term safety unknown.

How to read the evidence

Moderate evidence: promising phase 2 data reviewed; phase 3 trials ongoing for definitive efficacy and safety confirmation.

When this study was published

Published in 2025. Covers the latest clinical data for this first-in-class triple agonist.

The bigger picture

The progression from single GLP-1 drugs (semaglutide, ~15%) to dual agonists (tirzepatide, ~21%) to triple agonists (retatrutide, ~24%) shows how activating additional metabolic receptors incrementally improves weight loss. Retatrutide represents the current peak of peptide metabolic drug design.

Questions still open

Will phase 3 trials confirm the ~24% weight loss seen in phase 2?
Does triple agonism have a meaningfully different side effect profile than dual agonism?
Could retatrutide replace bariatric surgery for many patients?

Common questions

Is retatrutide better than semaglutide or tirzepatide?

Phase 2 data suggests retatrutide achieves more weight loss (~24%) than semaglutide (~15%) or tirzepatide (~21%) by activating an additional receptor (glucagon). However, phase 3 results are needed for definitive comparison, and side effects may differ.

When will retatrutide be available?

Retatrutide is in phase 3 clinical trials. If successful, it could receive regulatory approval within approximately 1-2 years. Keep in mind that approval timelines are uncertain.

Read the original research

Efficacy and safety of retatrutide, a novel GLP-1, GIP, and glucagon receptor agonist for obesity treatment: a systematic review and meta-analysis of randomized controlled trials.

Proceedings (Baylor University. Medical Center), 38(3), 291-303

View on PubMed ↗Publisher’s paper ↗

Citation

Abdrabou Abouelmagd, Alaa; Abdelrehim, Amro Mamdouh; Bashir, Mohamed Nabih; Abdelsalam, Fares; Marey, Ahmed; Tanas, Yousef; Abuklish, Duha Milad; Belal, Mohamed Mohamed. (2025). Efficacy and safety of retatrutide, a novel GLP-1, GIP, and glucagon receptor agonist for obesity treatment: a systematic review and meta-analysis of randomized controlled trials.. Proceedings (Baylor University. Medical Center), 38(3), 291-303. https://doi.org/10.1080/08998280.2025.2456441