Epithalon is among the simplest compounds in any peptide catalogue: four residues, all standard, no modifications. That makes its identity unusually easy to confirm, and it throws the harder question into relief, which is what the published work supports.
The sequence
Ala-Glu-Asp-Gly, written AEDG in one-letter code. Four of the twenty standard amino acids, a free N-terminus and a free C-terminus, nothing bound and nothing methylated.
That simplicity means you can check the catalogue figures yourself in two independent ways, which is rare. Put AEDG into our molecular weight calculator and it returns C14H22N4O9 at 390.35 g/mol. Look up CAS 307297-39-8 and PubChem returns a record with the same formula and the same mass. Two routes that do not depend on each other, both agreeing with what the listing says.
The CAS number also passes the check digit, which you can confirm with our validator. Three checks on one compound, all of them available before anyone pays for anything.
What the composition tells you
Two of the four residues are acidic, glutamate and aspartate, and neither of the other two carries a charge. So this is a markedly acidic peptide, and our isoelectric point calculator puts its pI low, which is where solubility is at its minimum.
The composition also says what cannot go wrong. No methionine or cysteine means no sulfur, so the oxidation route that adds sixteen mass units to methionine-containing peptides has nowhere to act here. A formula with no S in it tells you that for free.
Asparagine and glutamine are the residues most prone to deamidation, and this sequence has neither. It does have aspartate, which can isomerise, so the sequence is not inert, but the usual short list of degradation routes is shorter than normal.
A compound you can check without the seller
Most of this site argues that a buyer should be able to confirm a claim independently. Epithalon is the clearest case on the shelf, because every structural claim about it is reachable from public sources in under a minute.
The sequence gives the formula. The formula gives the mass. The CAS number gives a registry record that states both. If a certificate for this compound disagrees with any of that, the disagreement is about the document and not about what the molecule is. Few compounds let you draw that line so cleanly, and it is worth using where you can.
Why high purity is expected, not impressive
Three coupling steps. That is the entire synthesis, and each step is the only kind of opportunity a peptide has to go wrong in assembly. A tetrapeptide of standard residues is about as easy as this chemistry gets, so a figure of 99 percent here represents very little work compared with the same figure on a long chain.
Purity percentages are not comparable across lengths, and on a compound this short the purity number is the easy half of the answer. The identity measurement is the one worth reading, and on this compound it is also easy to check against a public record.
The part that deserves caution
The chemistry is settled; the biology is not. Published work on this compound is thinner and more concentrated in a smaller set of groups than on compounds like the incretins or the copper peptides, and reviews of it are recent. (Reference: Araj et al., 2025)
We are not going to summarise claims about what it does, for the same reason this site does not do so for anything else: a catalogue page is not where that question gets settled, and a thin literature is exactly the situation where a seller restating claims adds the least and risks the most.
A seller can state the sequence, the formula, the mass, the batch and the method. On this compound all five are checkable against sources that have nothing to do with us, which is a better thing to offer than a summary.
Two names on the same molecule
Catalogues write this compound as both epithalon and epitalon, and PubChem indexes it under the second. Neither spelling is wrong and nothing turns on which one a seller uses, but a search under one may return less than a search under the other.
This is the ordinary case our note on CAS numbers describes: names drift and multiply, while a registry number stays put. On a compound whose chemistry is this easy to confirm, going through the number instead of the name removes the last place ambiguity could hide.
What a certificate should show
Purity from RP-HPLC with the column, gradient and detection wavelength written out. Identity from mass spectrometry with observed and theoretical mass both given, so you can compare the first against the PubChem formula yourself.
Net peptide content as a separate line. This matters more here than on a long peptide: at 390 daltons the molecule is light, so the trifluoroacetate counterion left by reversed-phase purification is a large share of the weighed powder. Our note on what else is in the vial works through the arithmetic.
Storage
Four residues give the ordinary degradation routes little to work with, and the sequence lacks the two that usually cause trouble. Hydrolysis of the backbone still applies, and it proceeds with time and temperature like everything else. (Reference: Manning et al., 2010)
The dry solid is hygroscopic once a vial is open, which is true of lyophilised material generally. A certificate is dated because a result belongs to a moment, and what happens afterwards is handling. Our note on storage covers the routes.
Research use only
All products sold by Codex Research are strictly for laboratory research and development. They are not for human or animal consumption and are not intended to diagnose, treat, cure, or prevent any disease.
The compound at Codex Research
Epithalon, 10 mg per vial · batch-verified, with its certificate of analysis.
Frequently asked questions
What is epithalon?
The tetrapeptide Ala-Glu-Asp-Gly, written AEDG, made of four standard amino acids with no modifications at either terminus.
What is the formula and mass of epithalon?
C14H22N4O9, 390.35 g/mol, CAS 307297-39-8. A sequence calculator and the PubChem record agree on both figures, which is two independent confirmations.
Can I verify epithalon myself before buying?
Yes, in three ways that do not involve the seller: calculate the formula from AEDG, look up the CAS number and compare, and run the check digit on that number.
Why is a high purity figure unremarkable on epithalon?
Three coupling steps make up the whole synthesis, and all four residues are standard. A tetrapeptide is about as easy as this chemistry gets, so 99 percent here represents far less work than on a long chain.
What degradation routes does this sequence avoid?
It has no methionine or cysteine, so there is no sulfur to oxidise, and no asparagine or glutamine, the residues most prone to deamidation. It does carry aspartate, which can isomerise.
How strong is the published literature on epithalon?
Thinner and concentrated in a smaller set of groups than for compounds like the incretins or copper peptides, with recent review coverage. The chemistry is settled; the biology is not, which is why this page states the chemistry and stops.
References
- Araj, S.K., et al. (2025). Overview of epitalon, a highly bioactive pineal tetrapeptide. International Journal of Molecular Sciences, 26(6), 2691.
- Epitalon compound summary (CID 219042). PubChem, National Library of Medicine.
- Merrifield, R.B. (1963). Solid phase peptide synthesis. I. The synthesis of a tetrapeptide. Journal of the American Chemical Society, 85(14), 2149-2154.
- Dong, M.W. (2006). Modern HPLC for Practicing Scientists. Wiley.
- Manning, M.C., Chou, D.K., Murphy, B.M., Payne, R.W., & Katayama, D.S. (2010). Stability of protein pharmaceuticals: an update. Pharmaceutical Research, 27(4), 544-575.