Pinealon and epithalon are the two pineal-derived short peptides from the St Petersburg bioregulator programme, and they are the pair most often compared by people deciding which to order. They are not variants of one another. One is three residues, the other four; they share two residues in the middle and differ in everything else, including vial size, molar amount per vial and the shape of their literature. This post puts them side by side on each of those axes. The pinealon post is the deep version for one; the series comparison covers all six of the family in one table.
What are the two sequences?
| Pinealon | Epithalon | |
|---|---|---|
| Sequence | Glu-Asp-Arg (EDR) | Ala-Glu-Asp-Gly (AEDG) |
| Residues | 3 | 4 |
| Formula | C15H26N6O8 | C14H22N4O9 |
| Average mass | 418.4 | 390.3 |
| CAS | 175175-23-2 | 64082-79-7 |
| PubChem CID | 10273502 | 219042 |
| Net charge near pH 7 | about minus 1 | about minus 2 |
| Chromophore | none beyond the peptide bond | none beyond the peptide bond |
Both contain the Glu-Asp pair. Pinealon ends in arginine, which carries a positive charge and makes the molecule a zwitterion; epithalon begins with alanine and ends with glycine and carries only negative charges at neutral pH. Neither has an aromatic residue, so neither absorbs at 280 nm and both are measured by HPLC at 214 nm. Neither has cysteine, methionine or tryptophan, so neither has an oxidation or light problem. Both have an aspartic acid, and epithalon's is followed by glycine, the Asp-Gly motif that isomerises more readily than most; that is the one handling difference worth noting, covered below.
Epithalon's name is spelled two ways, epithalon and epitalon, in the literature and in catalogues. They are the same peptide. The programme's original pineal extract was called Epithalamin, and the tetrapeptide was designed from it; pinealon was designed from the same source material by the same compositional method.
What do the two certificates report?
Both lots on sale were tested by Bioviridian Inc. and both certificates were issued on 17 August 2026.
| Test | Pinealon, lot PINE20-0803, COA7610 | Epithalon, lot EPIT10-0803, COA7622 |
|---|---|---|
| Identity, LC-MS/MS | 418.4 | 390.3 |
| Purity, RP-HPLC 214 nm | 99.68% | 99.68% |
| Retention time | 1.96 min | 2.04 min |
| Content | 20.80 mg against 20 mg | 10.63 mg against 10 mg |
| Endotoxin, LAL | < 0.05 EU/mL | < 0.05 EU/mL |
| Heavy metals, ICP | < 0.01 ppm | < 0.01 ppm |
The two certificates are as close to identical in quality as two lots get. Both identities are by tandem MS, which reads the fragment ladder and not only the mass, so both are sequence-level identities; the LC-MS post explains why that matters for small peptides whose single masses could in principle be shared. Both purities are the same figure by area at 214 nm. Both retention times are short, under two and a half minutes, because both peptides are very polar; the area-percent post explains why a purity figure on an early-eluting peptide leans on the identity line for support.
Both certificates can be checked against the laboratory's copy at the verification page linked from the COA library.
How do the vials compare in molar terms?
This is where the comparison stops being symmetrical.
| Pinealon | Epithalon | |
|---|---|---|
| Vial | 20 mg | 10 mg |
| Micromoles per vial, by label | 47.8 | 25.6 |
| Micromoles per vial, by measured content | 49.7 | 27.2 |
| Listed price, 2 October 2026 | $60 | $60 |
| Price per micromole | about $1.25 | about $2.34 |
The two are listed at the same price and the pinealon vial holds almost twice the molar amount. Whether that matters depends on the study: at the micromolar concentrations the published cell work used, 25 micromoles is still thousands of wells, and a single vial of either outlasts most experiments. The vial-size post and the molarity post cover how to compare on these terms properly.
What does each literature actually contain?
Here the asymmetry runs the other way.
Epithalon has the more specific and more cited body of work. The 2003 paper by Khavinson, Bondarev and Butyugov in the Bulletin of Experimental Biology and Medicine reported telomerase activity and telomere elongation in cultured human somatic cells exposed to the peptide. That is a specific, measurable, in-vitro claim with a defined readout, and it is the reason epithalon is the better known of the two. The group's wider work on epithalon in aged animals is summarised in its reviews.
Pinealon has a smaller literature centred on the 2011 Rejuvenation Research paper, which reported increased viability, reduced free-radical measurements and proliferative effects in cultured cells.
What the two have in common is the profile of the whole series: the work is mainly from one laboratory, in cells and rodents, with independent replication sparse and no registered clinical trial for either. A search of ClinicalTrials.gov on 2 October 2026 found none. The bioregulator evidence post is the longer treatment of what that means for a study design, and it applies equally to both.
How should a researcher choose?
By the readout the study needs, not by the name.
- A study reproducing or extending the telomerase work has one obvious compound, epithalon, and a defined assay to reproduce.
- A study on cell viability or oxidative measurements in culture has pinealon's paper as its nearest precedent.
- A study of the series as a class, which the series comparison is built for, needs both and probably vilon and vesugen as well, run in parallel with the same controls.
- A study that needs a very polar, non-aromatic, non-oxidising short peptide as a control for something else can use either; pinealon gives twice the molar amount for the money.
What handling differs?
Very little. Both dissolve instantly in water. Both are stored lyophilized at minus 20 °C and as frozen aliquots in solution. The one difference is epithalon's Asp-Gly motif, which is the classic site for isomerisation to isoaspartate and for succinimide formation; at neutral pH and cold it is slow, at alkaline pH it is not. Hold epithalon stocks near neutral and do not leave them warm. Pinealon's aspartate is followed by arginine, which is a less reactive neighbour. The reconstituted shelf-life post has the general rules, and the diluent post covers when reconstitution solution is appropriate for either.
Frequently asked questions
Is epithalon just pinealon plus a residue?
No. Pinealon is Glu-Asp-Arg and epithalon is Ala-Glu-Asp-Gly. They share Glu-Asp and differ at both ends. Epithalon is the lighter molecule despite having one more residue, because alanine and glycine are small and arginine is large.
Are epithalon and epitalon different compounds?
No. Two spellings of one tetrapeptide, Ala-Glu-Asp-Gly, CAS 64082-79-7.
Why is pinealon sold in 20 mg and epithalon in 10 mg?
Catalogue sizing, which this comparison does not try to justify beyond the arithmetic: at the listed prices the pinealon vial holds about twice the micromoles. Both sizes are far more than one in-vitro study consumes.
Which has the better evidence?
Epithalon has the more specific published claim, the 2003 telomerase paper, with a defined in-vitro readout. Neither has independent large-scale replication or a registered clinical trial.
Which should I order?
The one whose published assay matches the readout you intend to measure. For a class study, both. Both are sold for laboratory research use only and not for human or animal use.
References
- Khavinson VK, Bondarev IE, Butyugov AA. Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells. Bulletin of Experimental Biology and Medicine 2003;135(6):590-592. doi.org/10.1023/a:1025493705728
- Khavinson V, Ribakova Y, Kulebiakin K, et al. Pinealon increases cell viability by suppression of free radical levels and activating proliferative processes. Rejuvenation Research 2011;14(5):535-541. doi.org/10.1089/rej.2011.1172
- PubChem, National Library of Medicine. Epitalon, CID 219042, C14H22N4O9, 390.35 g/mol. Read 2 October 2026. pubchem.ncbi.nlm.nih.gov/compound/219042
- PubChem, National Library of Medicine. Pinealon, CID 10273502, C15H26N6O8, 418.4 g/mol. Read 2 October 2026. pubchem.ncbi.nlm.nih.gov/compound/10273502
- Bioviridian Inc. Certificates COA7610 (lot PINE20-0803) and COA7622 (lot EPIT10-0803), both issued 17 August 2026. bioviridians.com/coa-search.html
Every product mentioned is sold for laboratory research use only and is not for human or animal use. Nothing on this page describes or recommends use of the material sold here in humans or animals.
