◆ Weightloss · Comparison · Incretin Agonists
Semaglutide vs Tirzepatide vs Retatrutide: A Research Comparison
A verified side-by-side comparison of three generations of incretin-based compounds — single, dual and triple receptor agonists — by receptor target, structure, and published efficacy.
Silverback Research Team
Independent Literature Review
Compound Data
✓ Research Grade| Semaglutide | GLP-1R agonist · FDA & TGA approved (Ozempic/Wegovy) |
| Tirzepatide | GLP-1R/GIPR dual agonist · FDA & TGA approved (Mounjaro/Zepbound) |
| Retatrutide | GLP-1R/GIPR/GCGR triple agonist · investigational only |
Research use only. All information is sourced from published literature for informational purposes. Silverback Peptides products are strictly for laboratory research. Not for human consumption, therapeutic use, or veterinary use.
Overview
Key Takeaways
- These three compounds represent successive generations of incretin pharmacology: single (semaglutide), dual (tirzepatide), and triple (retatrutide) receptor agonism.
- Semaglutide and tirzepatide are approved by both the FDA and TGA. Retatrutide remains investigational with no regulatory approvals.
- In their respective pivotal trials, headline mean weight loss increased with each added receptor target — though these come from separate trials and are not head-to-head.
This comparison summarises the published receptor profiles and pivotal-trial efficacy of three widely studied incretin-based compounds. An important caveat: the figures below come from separate trials with different populations, durations and doses — they are not direct head-to-head comparisons. Silverback Peptides supplies these strictly for laboratory research.
Side-by-Side Comparison
The table below summarises the key differentiators across the three compounds.
| Parameter | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Receptor targets | GLP-1R | GLP-1R · GIPR | GLP-1R · GIPR · GCGR |
| Regulatory status | FDA & TGA approved | FDA & TGA approved | Investigational |
| Pivotal trial | STEP-1 | SURMOUNT-1 | Phase 2 / TRIUMPH-1 |
| Mean weight loss | −14.9% (68 wk, 2.4mg) | −22.5% (72 wk, 15mg) | −24.2% Ph2 48wk / −28.3% TRIUMPH-1 80wk |
Interpreting the Data
Key Takeaways
- More receptor targets has tracked with greater mean weight loss across these trials — but cross-trial comparison is not equivalent to a head-to-head study.
- The retatrutide TRIUMPH-1 80-week figure is recent (2026) topline data; confirm against the primary publication before relying on it.
The progression from single to triple agonism has been associated with progressively greater mean weight reduction. Semaglutide acts via selective GLP-1R agonism; tirzepatide adds GIPR for synergistic insulinotropic action; retatrutide adds glucagon-receptor agonism, which increases energy expenditure and hepatic fat oxidation.
These figures are drawn from separate pivotal trials and should not be read as a direct comparison. The retatrutide 80-week TRIUMPH-1 figure in particular is recent topline data and should be verified against the final peer-reviewed publication.
References
- [1] Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. DOI ↗
- [2] Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205-217. DOI ↗
- [3] Coskun T, Urva S, Roell WC, et al. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss. Cell Metab. 2022;34(9):1234-1247. DOI ↗