Pinealon Sequence: The Glu-Asp-Arg (EDR) Tripeptide

Three amino acids. Two peptide bonds. That is the whole molecule, and the entire pinealon sequence weighs roughly 418 daltons, about a tenth of the mass of semaglutide and smaller than almost anything else sitting beside it in a research freezer.

What is the pinealon sequence?

The pinealon sequence is Glu-Asp-Arg, written EDR in single-letter code and H-Glu-Asp-Arg-OH as the free acid. Its molecular formula is C15H26N6O8, with an average molecular mass near 418.4 g/mol and a monoisotopic mass near 418.18 Da. At pH 7.4 the molecule carries a net charge of about -1, which drives its solubility and its chromatographic behaviour.

Searches for pinealon peptide sequence, pinealon structure, glu-asp-arg and pinealon tripeptide all resolve to the same chemistry, and that chemistry is unambiguous. The common misconception is that pinealon is a glandular extract or a branded variant of epitalon. It is neither: it is a fully synthetic tripeptide with a defined residue order and a different formula from epitalon. What follows covers the structure and mass arithmetic, ionisation at physiological pH, where EDR sits among the short peptide bioregulators, how the pinealon sequence is confirmed analytically, and what the published literature has actually examined.

What exactly is the Glu-Asp-Arg tripeptide?

The Glu-Asp-Arg tripeptide is a linear chain of three proteinogenic L-amino acids: L-glutamic acid at the N-terminus, L-aspartic acid in the middle, and L-arginine at the C-terminus. Written in standard N-to-C convention it reads H-Glu-Asp-Arg-OH, abbreviated EDR. There is no cyclisation, no disulfide bridge, no N-terminal acetylation, and no non-canonical residue in the reference structure.

Two features define its character. Two of the three side chains are ionisable carboxylates (the gamma-carboxyl of glutamate and the beta-carboxyl of aspartate), and the third is a guanidinium group on arginine, which stays protonated across the entire physiological range. That pairing of two acidic residues with one strongly basic residue is what makes the pinealon sequence behave the way it does in water, on a column, and in an electrospray source.

A recurring source of confusion in catalog listings is the assumption that pinealon is a pineal extract. It is not. Material described as EDR is assembled by solid-phase peptide synthesis, residue by residue, then cleaved and lyophilised, which is precisely why the sequence can be verified independently rather than assayed as a mixture. The free acid and the C-terminal amide are also distinct compounds: the amide form is lighter by roughly one mass unit, and a certificate that reports 417.4 instead of 418.4 is describing the amide, not the acid. Catalog reference material for the compound sits on the pinealon overview page and the Pinealon 10mg listing.

Which molecular formula and mass correspond to this structure?

The formula C15H26N6O8 is derived by summing the three residue formulas and subtracting the two water molecules lost when the peptide bonds form. The arithmetic is deterministic, which is why every honest certificate reports the same numbers for the pinealon sequence.

Both numbers matter for different reasons. The average mass near 418.4 g/mol is the figure used for gravimetric work and the figure printed on most certificates. The monoisotopic mass of 418.18 Da is the figure a mass spectrometer is actually measuring, with the protonated species [M+H]+ appearing near m/z 419.19 in positive-mode electrospray and the deprotonated [M-H]- near m/z 417.17 in negative mode. A supplier certificate that reports an observed mass several units away from those values is describing a different molecule, a salt adduct, or a degradation product, and the difference is worth understanding before anything else on the document is read. Background on how those values are generated is covered on the mass spectrometry peptide verification page.

What charge does the molecule carry at physiological pH?

At pH 7.4 the EDR tripeptide carries a net charge of approximately -1. The arithmetic runs through five ionisable groups, using standard reference pKa values for free amino acids as the approximation.

The C-terminal carboxyl of arginine (pKa near 2.2) is deprotonated, contributing -1. The aspartate side chain (pKa near 3.7) is deprotonated, contributing -1. The glutamate side chain (pKa near 4.2) is deprotonated, contributing -1. The N-terminal alpha-amino group of glutamate (pKa near 9.0 to 9.6) is protonated, contributing +1. The arginine guanidinium group (pKa near 12.5) is protonated, contributing +1. Three negatives and two positives leave a net -1.

That calculation also places the isoelectric point in the acidic range, somewhere near pH 4, between the aspartate and glutamate side-chain pKa values. Practical consequences follow directly. The pinealon sequence is strongly hydrophilic and dissolves readily in aqueous buffers. It retains poorly on reversed-phase C18 columns without an ion-pairing agent such as trifluoroacetic acid, and it tends to elute early in a standard analytical gradient, which is exactly why a short retention time on an EDR chromatogram is expected rather than suspicious. Anion-exchange separation is feasible because of the net negative charge. For context on how those chromatograms are read, see the HPLC peptide purity explainer.

Where does EDR sit among the short peptide bioregulators?

EDR belongs to a family of di-, tri- and tetrapeptides described in the Russian gerontology literature as short peptide bioregulators, a research programme associated with Vladimir Khavinson and the St. Petersburg Institute of Bioregulation and Gerontology. The table below compares the four most frequently referenced members by sequence and physicochemical profile. Masses are calculated as free acids from standard residue masses.

The comparison matters because the names are used loosely online while the molecules are not interchangeable. Epitalon and the pinealon sequence differ in residue count, formula, mass and net charge, so no analytical result for one substitutes for the other. Side-by-side reading is available on the epitalon vs pinealon comparison, the epithalon overview, the what is epithalone explainer, the epithalon research summary and the pinealon vs DSIP structural comparison.

Why does the residue order in the pinealon sequence matter?

Here is the detail most structural write-ups skip: a scrambled version of EDR has an identical molecular formula and an identical intact mass. Reverse the order to RDE, or swap the acidic residues to DER, and the instrument still reads 418.18 Da monoisotopic and 418.4 average. Intact mass confirmation proves composition. It does not prove sequence.

Sequence isomers are distinguished by tandem mass spectrometry, where the molecule is fragmented along the backbone and the resulting b-ion and y-ion series are read against the expected pattern for Glu-Asp-Arg. Edman degradation, which removes and identifies one residue at a time from the N-terminus, is the classical orthogonal method. Amino acid analysis after acid hydrolysis confirms the 1:1:1 ratio of glutamate, aspartate and arginine but, again, says nothing about order.

Synthesis errors split into two categories, and only one is easy to catch. Deletion sequences, where a residue fails to couple, change the mass measurably: losing the central aspartate would leave Glu-Arg at roughly 303.3 g/mol, which no mass spectrometer would mistake for the parent. Isobaric errors, including scrambling and isoaspartate formation, leave the mass untouched and are caught only by fragmentation or chromatographic resolution. That asymmetry is the single strongest argument for insisting on both a chromatogram and a mass spectrum rather than one or the other, a trade-off laid out on the HPLC vs mass spectrometry comparison page.

What has the published literature actually examined?

The research record on the pinealon sequence is narrower than the volume of online discussion suggests. Most of it comes from the Khavinson research programme and collaborators, is indexed on PubMed under the author name Khavinson VKh, and appears substantially in Bulletin of Experimental Biology and Medicine alongside Russian-language gerontology and neuroendocrinology journals.

The published work is preclinical. It covers cell-free systems examining peptide interaction with nucleic acids, cultured neuronal and other cell models, and rodent experiments including models of hypoxia and models of prenatal stress. Reported endpoints in those papers are biochemical and histological markers rather than clinical outcomes. Independent replication by unaffiliated groups is limited, and the body of work is characterised by small experimental series rather than large multi-centre designs.

What the literature does not contain is any approved clinical indication, any large randomised controlled trial, or any regulatory review of EDR as a drug product in the United States. Claims circulating about sleep, cognition or longevity outcomes extend well past what has been demonstrated, and anyone reading those claims should trace them back to the primary source before accepting them. Research-history context for the wider bioregulator programme sits on the epithalon history page and the 2026 research news roundup, while the way sleep-related discussion has developed around this compound is addressed on the pinealon and sleep research page.

What mechanism do those papers propose?

The mechanism proposed in the Khavinson literature is direct peptide interaction with DNA and chromatin proteins. The argument runs that short, highly charged peptides of this size can enter cells and nuclei, associate with specific sequences in the DNA major groove or with histone proteins, and modulate transcription of associated genes. Molecular modelling and docking papers from the same programme support the proposal computationally.

The structural logic is at least internally consistent. At 418 Da with a net negative charge and no hydrophobic bulk, the pinealon sequence is small, polar and unlikely to behave like a classical receptor ligand. Its charge distribution, two carboxylates against one guanidinium, resembles the electrostatic complementarity that DNA-binding motifs exploit.

Let's be direct about this: the structural chemistry of EDR is settled, and the mechanism is not. A sequence-specific peptide-DNA interaction that modulates gene expression is a hypothesis with modelling support and preclinical data from a largely single-source research programme. It is not established consensus pharmacology, it has not been validated by independent laboratories at scale, and it should be described as a proposal rather than a finding. Readers comparing mechanistic stories across this category will find the same caveat applies to adjacent discussions on the epithalon and NAD comparison and the NAD and epithalon research page.

Which analytical methods confirm the sequence?

Confirming that a vial contains the pinealon sequence rather than something adjacent requires more than one test, because no single method covers identity, sequence and impurity profile at once.

Reversed-phase HPLC with ultraviolet detection produces the purity profile and shows whether the main peak is accompanied by closely eluting related substances. Electrospray mass spectrometry confirms the intact molecular mass against the expected 418.18 Da monoisotopic value. Tandem MS fragmentation confirms residue order. Amino acid analysis confirms composition. Supporting tests on a complete certificate typically include water content by Karl Fischer titration, residual solvent analysis, and counterion content, which for a peptide of this kind is usually acetate or trifluoroacetate left over from synthesis and purification.

A certificate without an attached chromatogram and spectrum is a claim, not evidence. Real Peptides publishes lot certificates of analysis at the CoA archive, and the practical skill of reading one, matching lot numbers, checking the analytical date and confirming the reported mass, is walked through on the how to read a peptide CoA guide. Where the reported figures sit relative to general research-grade standards is covered on the peptide purity levels page.

What does the structure predict about stability and storage?

The residue composition of the pinealon sequence predicts two specific degradation routes, and both are detectable if the right method is used.

An N-terminal glutamate can cyclise to pyroglutamate, losing a molecule of water and shifting the measured mass down by roughly 18 Da. That route is accelerated by heat and by time in aqueous solution, and it produces a species that mass spectrometry flags immediately. The second route is harder to see. Aspartate residues can cyclise through a succinimide intermediate and resolve to isoaspartate, which is isobaric with the parent peptide. The mass does not change. Only chromatographic separation or targeted fragmentation reveals it, which is one more reason intact mass alone is an incomplete identity check.

Beyond chemistry, the lyophilised powder is hygroscopic, and absorbed atmospheric moisture is the practical starting point for hydrolysis. Material held dry, cold and protected from light is substantially more stable than the same material in solution, and repeated freeze-thaw cycles on aqueous stocks accelerate loss. In biological systems, short peptides of this size are cleared rapidly by circulating and tissue peptidases, which is the subject of the pinealon half-life page. Laboratory handling principles are set out on the peptide storage guide, the degradation pathways explainer, the lyophilised vs liquid stability comparison and the epithalon storage page.

What is the regulatory status of EDR material?

EDR is not an approved drug in the United States. It has not been reviewed or authorised by the FDA as a therapeutic product, it holds no approved indication, and it is not a dietary ingredient. Material supplied under the name pinealon is laboratory chemical inventory, and its legitimate use is in vitro and preclinical research.

All compounds discussed on this page are sold for laboratory research use only and are not for human consumption.

Nothing on this page is guidance for use in a person or an animal, and no quantity, schedule or handling instruction for living subjects is given or implied. Questions about animal health belong with a licensed veterinarian, and questions about personal health belong with a physician. Legal status for possession and import varies by jurisdiction and changes, so the position in one country says nothing reliable about another. Jurisdictional detail and the meaning of the research-use-only designation are covered on the pinealon legality page, the epithalon legality page and the research use only explainer.

How was this page researched?

The structural figures here are calculated rather than quoted. The molecular formula for the pinealon sequence was derived by summing the standard residue formulas for glutamic acid, aspartic acid and arginine and subtracting two water molecules for the two peptide bonds. Average and monoisotopic masses were computed from standard residue mass tables, and the net charge at pH 7.4 was derived from reference pKa values for free amino acid side chains and termini, which makes it an approximation rather than a measured titration result.

Literature scope was established by searching PubMed for the EDR sequence terms and for the principal author associated with the short peptide bioregulator programme, then reading what those records describe in terms of model systems and endpoints. Where the evidence base is dominated by a single research group, that has been stated plainly rather than smoothed over.

No first-party laboratory testing is claimed anywhere on this page. Analytical descriptions reflect standard peptide characterisation practice, and lot-specific data for catalog material lives on the published certificates rather than in this text.

What should be remembered about EDR?

• The pinealon sequence is Glu-Asp-Arg (EDR), a linear tripeptide of three L-amino acids with no cyclisation, bridging or non-canonical residues.
• Its molecular formula is C15H26N6O8, with an average mass of about 418.4 g/mol and a monoisotopic mass of about 418.18 Da, giving [M+H]+ near m/z 419.19.
• At pH 7.4 the molecule carries a net charge of roughly -1, from three deprotonated carboxylates against a protonated N-terminus and guanidinium group, placing its isoelectric point in the acidic range.
• Intact mass confirms composition but not residue order, because scrambled sequences such as RDE and DER are isobaric with EDR and require MS/MS fragmentation or Edman sequencing to exclude.
• The two structurally predicted degradation routes are N-terminal pyroglutamate formation, which shifts mass by about 18 Da, and aspartate-driven isoaspartate formation, which does not change mass at all.
• Published EDR research is preclinical, concentrated in a single research programme, and carries no approved clinical indication.

Where does this fit with the related research pages?

Researchers working through this compound family usually move between the structural material and the practical documentation. Supporting reading includes the epithalon FAQ for questions that recur across the bioregulator group, the epithalon half-life page for clearance comparisons between a tetrapeptide and a tripeptide, the epithalon sourcing page for how research-grade listings are documented, and the shipping and handling page for cold-chain considerations that apply to lyophilised short peptides generally.

The pinealon sequence is one of the rare cases where the chemistry is easier to settle than the conversation around it. Three residues, one formula, one mass, one charge state at blood pH, all of it verifiable with instruments that any competent analytical laboratory already owns. The uncertainty lives entirely downstream, in what a 418-dalton molecule with two carboxylates and a guanidinium group actually does inside a cell, and that question has not been answered by the kind of independent, replicated work that would settle it. Treat the structure as fact and the mechanism as an open file.