Epitalon (Epithalon, AEDG): identity and what to check

Epitalon is a synthetic tetrapeptide, sequence Ala-Glu-Asp-Gly, abbreviated AEDG, CAS 307297-39-8, formula C14H22N4O9, calculated mass 390.35 g/mol. It has no marketing authorisation in the UK or the EU. Being only four residues long, it is cheap to synthesise and unusually easy to report at a high purity figure - which is why the purity figure is the least useful number on its certificate.

Nomenclature: Epitalon, Epithalon, Epitalone, AEDG

Four spellings, one molecule. Epitalon and Epithalon are both common in the literature, Epitalone appears in supplier catalogues, and AEDG is simply the one-letter sequence read aloud: Ala-Glu-Asp-Gly. The CAS number, 307297-39-8, is the identifier that resolves all of them.

The compound is discussed in a research literature originating largely in Russian-language gerontology and continued elsewhere; a recent overview appeared in the International Journal of Molecular Sciences in 2025 (PubMed 40141333), and the wider record can be searched on PubMed. Peptorium does not summarise that work, does not carry it across to people or animals, and states no outcome of any kind. Much of the marketing attached to this peptide does exactly the opposite, which is a reason to read the primary record rather than a shop.

Identity: a four-residue sequence

The sequence is Ala-Glu-Asp-Gly, formula C₁₄H₂₂N₄O₉, mass 390.35 g/mol, listed publicly as PubChem CID 219042. Two of the four residues, glutamic acid and aspartic acid, carry side-chain carboxyl groups, which makes the peptide markedly acidic and freely soluble in water. It is a small molecule by peptide standards - lighter than a single residue of many of the compounds elsewhere on this site.

Shortness cuts both ways for a buyer. A four-residue chain is straightforward to assemble, so a genuinely high purity is easy to achieve and a high figure on a certificate is therefore weak evidence of anything: it does not distinguish a careful supplier from a careless one. What does distinguish them is the measured mass beside the theoretical 390.35, the impurity table, and whether peptide content was measured at all - because with a peptide this light, the counter-ion and residual water make up a proportionally larger share of what is in the vial than they would for a heavier chain.

Regulatory status in the UK and the European Union

Epitalon has no marketing authorisation. It is not in the EMA medicines database, it is not licensed in the United Kingdom, and it is not an authorised food supplement. In the UK, regulation 46 of the Human Medicines Regulations 2012 prohibits selling, supplying or offering an unauthorised medicinal product, and regulation 2 defines such a product by how it is presented as well as by what it does. That presentation limb is the trap around this particular compound, because the claims commonly attached to it in advertising are exactly the kind that bring a chemical inside the definition of a medicine.

"Research use only" is a purpose, not a permission

It is a statement of intended purpose by a seller: the material is offered for laboratory work and not for use in people. It is not a legal category in the UK or the EU, not a licence, and not evidence that any authority has assessed anything. It is not a quality claim, and it does not cure a claim made elsewhere on the same page.

Purity, peptide content and a very light peptide

Purity by HPLC is a ratio - the share of separated peak area belonging to the target. Peptide content is a quantity - the share of the vial's mass that is peptide at all, the balance being residual water and counter-ions left from synthesis and freeze-drying. Water is measured separately by Karl Fischer titration. For a 390 g/mol peptide the arithmetic of that balance is unforgiving: an acetate counter-ion is not a rounding error against a molecule this size, and a certificate that omits peptide content has left out the figure that matters most here. The purity and peptide content guide explains why the two cannot be derived from one another.

What Peptorium publishes about this material

This page publishes identity: the sequence, the molecular formula and a calculated mass of 390.35 g/mol. Each of those can be checked against a public register rather than taken on trust. Purity, peptide content and water describe one batch rather than a compound. Those figures belong on a certificate of analysis issued by the laboratory that tested that batch, and they travel with the material itself.

What to ask before buying

• Does the certificate report a measured mass beside the theoretical 390.35 g/mol?
• Is peptide content stated separately from purity, and is water reported by Karl Fischer? For a peptide this light, these are the informative figures.
• Which counter-ion - acetate or trifluoroacetate - and is it named?
• Is there a batch number, and a certificate for that batch alone?
• Are the impurity peaks listed with a chromatogram, and are the method and date named?
• Can the result be checked with the laboratory that produced it?

What is not known

• What a given vial contains cannot be known without analysing it.
• The published literature is largely animal and in vitro work, and this page draws no conclusion from it about anything else.
• Storage guidance for a lyophilisate is convention rather than a measured property of a particular lot.

Frequently asked questions

The lyophilisate is dissolved in bacteriostatic water, and the volume of solvent fixes the concentration of the resulting solution; the peptide calculator converts between the two. No quantity is recommended for any purpose. Material described here is for laboratory and in vitro research use only - see the research declaration.