Reference comparison
Retatrutide vs Tirzepatide
Both are synthetic incretin-receptor agonists developed as single molecules that engage more than one receptor. The difference between them is how many receptors, and which.
Research use only. Not for human or veterinary use. This page compares what each compound is and what published literature has examined. It does not describe outcomes, does not recommend either material, and is not guidance on use.
Side by side
| Retatrutide | Tirzepatide | |
|---|---|---|
| Class | GLP-1 / GIP | GLP-1 / GIP |
| CAS number | 2381089-83-2 | 2023788-19-2 |
| Molecular formula | C221H342N46O68 | C225H348N48O68 |
| Molecular weight | 4731.3 g/mol (parent peptide) | 4813.5 g/mol (parent peptide) |
| Sequence | 39 amino acids; Aib at 2 & 20; α-methyl-Leu13; Lys17 lipidated (C20 diacid–γGlu–AEEA); C-terminal amide | 39 amino acids; Aib at 2 & 13; Lys20 lipidated (C20 diacid–γGlu–2×AEEA); C-terminal amide |
| Vial strengths | 10 mg, 20 mg, 30 mg, 40 mg, 60 mg | 10 mg, 15 mg, 20 mg, 30 mg, 60 mg |
| From | $195 | $230 |
| Purity (current lot) | 99.78% | 99.08% |
| Physical form | Sterile freeze-dried powder | Sterile freeze-dried powder |
Every figure above is the published value for the lot currently in stock. How our testing works →
How they differ
Receptor targets
Tirzepatide is a dual agonist: it binds the GIP and GLP-1 receptors. Retatrutide is a triple agonist, adding the glucagon receptor to those two. This is the substantive structural difference between the two molecules and the reason retatrutide is described in the literature as a 'triple-G' agonist.
Origin and characterisation
Both originate from Eli Lilly programmes. Tirzepatide is the more extensively characterised of the two in published human pharmacology; retatrutide (LY3437943) has been described in receptor-pharmacology work and in rodent models, with clinical characterisation more recent and more limited.
Molecular scale
Both are lipidated peptides of roughly forty residues engineered for extended half-life, using a fatty-diacid chain to promote albumin binding. Their molecular weights are close; the sequences and the modification chemistry differ.
As supplied
Both ship as sterile lyophilised powder with an HPLC-MS certificate published against the specific lot. Retatrutide is stocked at three strengths and tirzepatide at two, so the practical difference for a laboratory is often how much material a single vial represents.
Both, as supplied
Retatrutide
- Retatrutide 10mg $105
- Retatrutide 20mg $130
- Retatrutide 30mg $145
- Retatrutide 40mg $170
- Retatrutide 60mg $195
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