Cortagen is a commercial designation for the tetrapeptide Ala-Glu-Asp-Pro. This is an identity reference: sequence, expected mass, analytical behaviour and verification. It makes no claim about what the compound does and contains no preparation, handling or dosing guidance.
The sequence behind the name
Cortagen is Ala-Glu-Asp-Pro, abbreviated AEDP. Four standard L-amino acids, average free-acid mass approximately 430 g/mol.
Structurally it is Cartalax (Ala-Glu-Asp) with a proline added at the C-terminus, and it differs from Epithalon (Ala-Glu-Asp-Gly) only in that fourth residue — proline in place of glycine, a difference of 40 Da. Three compounds sharing the same first three residues, sold under three unrelated names, is a good illustration of why the trade name is not an identifier.
What the proline does
Proline is the one residue in the standard set whose side chain loops back onto the backbone nitrogen. That has two practical effects on the analysis.
Cis–trans isomerism. The bond preceding a proline can adopt two conformations that interconvert slowly on the chromatographic timescale. On a well-resolved method this can present as a broadened peak or, occasionally, as a shoulder. It is a conformational artefact of the compound, not a second substance, and mistaking it for an impurity is a common misreading of proline-containing peptides.
Slightly better retention. The pyrrolidine ring is more hydrophobic than a glycine, so AEDP retains marginally better on C18 than the purely small-and-acidic sequences in the same family. Marginally — it is still an early-eluting, polar analyte that needs a shallow gradient to separate properly.
Detection
No aromatic residue is present, so there is no useful signal at 280 nm. Read at approximately 214 nm on the peptide bond. As with the rest of this family, a purity number published without the wavelength and gradient does not tell you enough to compare it against anyone else’s.
What an analysis should show
Column chemistry and dimensions, mobile phase and gradient, detection wavelength, retention time, integrated peak area with the integration window visible, and a mass confirmation near 430 g/mol for the free acid. Separately: net peptide content and the declared counter-ion form. If the trace shows a shoulder, a supplier who can tell you whether it is proline isomerism or a genuine second component is a supplier who has actually looked at their own data.
Confirming identity independently
Query public chemical databases on Ala-Glu-Asp-Pro rather than on the word Cortagen. Our product pages carry compound identity links that run those queries directly.
How Cortagen is supplied here
Cortagen 20mg is supplied as a lyophilised powder in a sealed vial, with an independent reverse-phase HPLC analysis published on the product page alongside net peptide content, counter-ion form and vial size. Vials carry no batch or lot numbers and are matched to their published test by crimp and cap colour.
Frequently asked questions
What is the sequence of Cortagen?
Ala-Glu-Asp-Pro (AEDP), a tetrapeptide.
How is Cortagen different from Epithalon?
One residue. Epithalon is Ala-Glu-Asp-Gly, Cortagen is Ala-Glu-Asp-Pro. They differ by roughly 40 Da and behave differently on a column, but they are close enough that mass confirmation should be read carefully rather than assumed.
What molecular weight should I expect?
Approximately 430 g/mol as the free acid; higher as a salt.
Why does my Cortagen peak look broad or show a shoulder?
Proline-containing peptides can show cis–trans conformational broadening on the bond preceding the proline. It is a property of the molecule rather than a contaminant, though it should be confirmed by mass rather than assumed.
Research use only. All products supplied by Battle Born Peptides are laboratory reference materials for in-vitro research and analytical use by qualified professionals. They are not drugs, foods, dietary supplements, cosmetics or medical devices; they are not approved by the FDA or any other regulator for use in humans or animals; and they are not intended to diagnose, treat, cure, mitigate or prevent any disease, or to affect the structure or any function of the body of humans or animals. Nothing in this article is preparation, handling or dosing guidance. See our full research-use terms.