Epithalon — also written epitalon — is the best known of a family of very short synthetic peptides that circulate under coined laboratory designations. This article is an identity reference for it: sequence, mass, chromatographic behaviour, and how a buyer verifies that a vial contains what the label says. It makes no claim about what the compound does and contains no preparation, handling or dosing guidance.
The sequence behind the name
Epithalon is the tetrapeptide Ala-Glu-Asp-Gly, abbreviated AEDG. Four standard L-amino acids, no non-natural residues, no terminal modification in the common free-acid form, average free-acid mass approximately 390 g/mol.
The family it belongs to, and why the names mislead
Epithalon is one of a group of two-, three- and four-residue synthetic peptides sold under coined names rather than systematic ones. The names carry no structural information at all, and several of the compounds share most of their sequence:
- Cartalax — Ala-Glu-Asp (AED), about 333 g/mol
- Cortagen — Ala-Glu-Asp-Pro (AEDP), about 430 g/mol
- Cardiogen — Ala-Glu-Asp-Arg (AEDR), about 489 g/mol
- Livagen — Lys-Glu-Asp-Ala (KEDA), about 461 g/mol
- Pinealon — Glu-Asp-Arg (EDR), about 418 g/mol
- Chonluten — Glu-Asp-Gly (EDG), about 319 g/mol
Four of those six share the Ala-Glu-Asp core and differ only in what is attached at the C-terminus. Nothing in the trade names tells you that. If you are comparing vendors, comparing sequences is the only comparison that means anything.
The analytical problem with very short peptides
Weak retention. A tetrapeptide of small, polar residues barely interacts with a C18 stationary phase. It elutes early, often near the solvent front, where it shares retention space with salts and polar synthesis residues. A generic gradient built for longer, more hydrophobic peptides will under-resolve it and return a flattering purity figure.
No aromatic residue. AEDG contains no tryptophan, tyrosine or phenylalanine, so there is nothing to detect at 280 nm. The analysis has to be read at approximately 214 nm on the peptide bond, where the mobile phase absorbs more and baseline quality matters more.
Counter-ion is a large share of the mass. A trifluoroacetate salt on a 390 g/mol peptide carries proportionally far more counter-ion mass than the same salt on a 3,000 g/mol peptide. The gap between chromatographic purity and net peptide content is widest exactly where the peptide is smallest, so both numbers are required and they answer different questions.
Practical consequence
For this category, ask for the method as well as the number. A purity figure for a short polar peptide is far more method-dependent than one for a longer, more hydrophobic compound, and a shallow gradient at 214 nm on an appropriate column is doing considerably more work than a generic method would.
Confirming identity independently
Search on the sequence, not the designation. Public chemical databases index these compounds by structure far more reliably than by trade name. Our product pages carry compound identity links that query those databases directly, which is the appropriate way to resolve a name that exists mainly as a commercial label.
How Epithalon is supplied here
Epithalon 10mg is supplied as a lyophilised powder in a sealed vial. These compounds sit in our chromatin and gene-expression peptides category, grouped by the pathway they are studied against rather than by any intended outcome. Each product page carries an independent reverse-phase HPLC analysis, 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 amino acid sequence of Epithalon?
Ala-Glu-Asp-Gly (AEDG), a tetrapeptide of four standard L-amino acids.
Is epitalon the same as epithalon?
Yes — the two spellings refer to the same AEDG tetrapeptide. Epithalamin is a different thing: a peptide preparation rather than this single defined sequence.
What molecular weight should the mass spectrum show?
Approximately 390 g/mol for the free acid. A salt form reads higher, which is why the counter-ion must be declared.
Why do two suppliers report different purity for the same peptide?
Because for short polar peptides the figure depends heavily on the column, gradient and detection wavelength. Compare methods before comparing numbers.
Do the vials carry a lot number?
No. Vials carry no batch or lot identifiers and are matched to their published test by crimp and cap colour.
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.