Tirzepatide and Retatrutide compared: chemistry, targets and regulatory records
Tirzepatide acts at the GIP and GLP-1 receptors. Retatrutide adds the glucagon receptor as a third target. Both are 39-residue lipidated peptides. Tirzepatide is an authorised medicine in the US, EU and UK; retatrutide is investigational.
Research-use information. This page summarises published literature and regulator records. It is not guidance for use, not medical advice, and not a statement that any material is suitable for use in people or animals.
How do Tirzepatide and Retatrutide differ on the facts?
| Fact | Tirzepatide | Retatrutide |
|---|---|---|
| Class | Lipidated dual GIP and GLP-1 receptor agonist (39 residues) | Lipidated triple GIP, GLP-1 and glucagon receptor agonist (39 residues) |
| Length | 39 residues | 39 residues |
| Molecular formula | C225H348N48O68 | C221H342N46O68 |
| Average molecular weight | 4813 g/mol | 4731 g/mol |
| Receptor or pathway background | Incretin and glucagon receptors | Incretin and glucagon receptors |
| FDA (Drugs@FDA) | 2 applications listed (Prescription) | No application listed |
| EMA (centrally authorised) | 1 authorised | No centrally authorised medicine listed |
| MHRA (Products) | Product documents found (106) | No product document found |
| WADA 2026 list | Not named | Not named |
| Studies in our library | 2 | 2 |
| PubMed records for the search terms | 157 | 197 |
| Registered studies (ClinicalTrials.gov) | 296 | 33 |
Data dates: chemistry checked against PubChem 2026-10-05; regulatory records 2026-10-05; WADA list 2026-10-05; PubMed counts 2026-10-05.
What do the cited papers say differs between Tirzepatide and Retatrutide?
- Retatrutide is described as a long-acting triple agonist at the GLP-1, GIP and glucagon receptors; tirzepatide as a dual GIP and GLP-1 receptor agonist.[1],[3]
- Both have 39 residues and a C20 fatty diacid chain per the catalog; their PubChem molecular formulas differ.
- A 2026 paper compared semaglutide, tirzepatide and retatrutide in human kidney cells and in mouse models.[2]
Nothing on this page ranks one compound above the other or states what either does for a person.
Which studies are cited on this page?
[1] Carneiro GRA, da Costa Nunes IK, Dos Santos Cardoso GR, Dos Santos PF, Padilha MC, Nogueira FCS, et al.. Detection and Excretion Profile of Retatrutide in Human Plasma and Urine by LC-HRMS: Implications for Antidoping Analysis. Rapid Commun Mass Spectrom. 2026;40:e70179.
LC-HRMS detection and excretion profile of retatrutide in human plasma and urine, for anti-doping analysis.
[2] Ding M, Li X, Wei Y, Wang J, Jiao B, Li C, et al.. Comparative effects of semaglutide tirzepatide and retatrutide on renal fibrosis in UUO and aged mice. iScience. 2026;29:117174.
Compared semaglutide, tirzepatide and retatrutide in human kidney cells and in mouse models of renal fibrosis and ageing.
[3] Willard FS, Douros JD, Gabe MB, Showalter AD, Wainscott DB, Suter TM, et al.. Tirzepatide is an imbalanced and biased dual GIP and GLP-1 receptor agonist. JCI Insight. 2020;5.
Measured receptor binding and signalling of tirzepatide at the GIP and GLP-1 receptors, reporting imbalanced and biased agonism.