When sourcing GLP-3 RT (the GLP-3RT peptide, retatrutide, listed here as RT-GLP3) as a research material, the name on the vial is not enough: you need the CAS number (2381089-83-2), a batch-specific certificate of analysis with HPLC purity, a mass-spectrometry identity result near 4731 Da, net peptide content and an endotoxin result.
"GLP-3 RT", "GLP3RT" and "GLP-3 peptide" are unregulated catalog labels for one compound. That makes verification, not branding, the basis of a purchasing decision. This guide covers the triple-agonist-specific checks and points to the deeper method guides rather than repeating them.
Why isn't the product name enough?
Catalog numbering such as GLP-1, GLP-2 and GLP-3 is a supplier convention, not a standard. Two vials with the same label can differ in sequence, in whether the lipid side chain is present, or in salt form. Only batch analytics can distinguish them. The background on the label itself is in the hub guide listed below.
What should a GLP-3 RT report show?
| Check | What to look for | Red flag |
|---|---|---|
| CAS number | 2381089-83-2 on the spec and report | Missing, or a different CAS |
| Lot traceability | Batch code on the report matches the vial | Generic report with no lot number |
| HPLC purity | Dated chromatogram with a dominant main peak and stated method | Purity percentage with no chromatogram |
| MS identity | Deconvoluted mass near 4731 Da (free peptide) | No mass result, or a mass that does not match |
| Net peptide content | Stated net content per vial | Only a label amount, no measured content |
| Endotoxin | Measured result for the batch | No endotoxin line |
The line-by-line reading of a report is in Reading a Retatrutide COA, Line by Line, and the HPLC and MS method detail is in How to Verify Retatrutide Purity.
Why does identity matter more for a triple agonist?
The three-receptor profile depends on the modified residues and the C20 fatty-diacid side chain. A truncated sequence, a deletion product or a species missing the lipid moiety has a different mass and shows up as a separate species in an MS trace, so a clean identity result protects the receptor-specific readouts you plan to run. The mass-spectrometry specifics for this compound are in Retatrutide Identity Confirmation by Mass Spectrometry.
Which molecular weight should you compare against?
The free-peptide average mass is about 4731 g/mol (C221H342N46O68). A listing that quotes a figure near 4845 is consistent with a trifluoroacetate salt form, because each TFA adds about 114 Da. Both can describe the same peptide; the report should say which basis it uses.
Where to source GLP-3 RT as a research material
Happy Peptides supplies RT-GLP3 (retatrutide) as a lyophilized research material in 10 mg, 20 mg and 30 mg vials. Recent batch reports listed on the product page cover identity, purity, net content and endotoxin results, and every batch report is searchable by batch number in the certificate of analysis library.
Related research guides
Research-use note
All materials discussed are supplied for in vitro laboratory research use only, and are not for human or animal use.
