F tier · safety concern
Crystagen has the thinnest record of the five: a small number of in vitro immunology papers from the originating group, no animal outcome study, no human data, no registered trial — and its amino-acid sequence could not be confirmed from any authoritative source, with retail listings giving conflicting designations.
Crystagen
Crystagen is a short peptide from Khavinson's St Petersburg group marketed as an immune 'bioregulator'. The retrievable evidence is a handful of cell-culture immunology reports — B-lymphocyte activation in aged spleen preparations, effects on thymocyte blast transformation and signalling — all from the originating group. Its sequence could not be verified against PubChem or the primary literature, and secondary sources disagree about it.
// we supply this one
available as a research reagent
≥ 98% HPLC · lyophilised powder · batch certificate published. Grade F above is our own and is not adjusted because we stock it.
the explanation
Crystagen is sold as an immune-system peptide from a Russian institute. The only studies are in cells in dishes, from the group that invented it, and there has never been a clinical trial. We could not even confirm which amino acids it contains — different sellers list different sequences — so material sold under this name cannot be verified.
regulatory status
No medicinal approval anywhere; research reagent, identity unverified
Crystagen has no marketing authorisation as a medicine in the UK, EU, or US, and no MHRA, EMA, or FDA record exists. A ClinicalTrials.gov query returns no registered study of Crystagen. In Russia it is distributed within the consumer 'Cytogens' peptide range associated with Khavinson's institute rather than as a registered medicine, and no Russian medicines-register entry could be verified; the group's own 2014 review of clinical results for its bioregulators does not include Crystagen. Because the sequence is unconfirmed and no public chemical reference record exists, identity cannot be checked against any authority. UK supply is as a research reagent only, not for human consumption.
how it works · proposed mechanism
The proposed mechanism is the family default — cell and nuclear entry followed by tissue-specific gene regulation, here directed at immune tissue. The supporting data are limited in vitro immunology readouts, and one of the group's own results is explicitly negative. Without a confirmed sequence, even the structure-activity premise cannot be evaluated.
B-cell activation in aged spleen culture
In spleen preparations from aged animals, Crystagen was reported to activate B-lymphocyte immunity. The effect was distinguished from Vilon and Thymogen, which the same paper reported acting on T-helper cells and via apoptosis inhibition respectively.
An explicit null result
The same study reported that Crystagen had no effect on cellular renewal processes in the aging spleen, unlike the comparator peptides. This is a negative finding published by the originating group and is worth weighting as such.
Thymocyte signalling effects
Earlier work reported effects of short peptides including Crystagen on thymocyte blast transformation and signal transduction pathways. These are isolated in vitro readouts with no downstream immune outcome measured.
Unverified structure-activity basis
The family's specificity claim depends on the exact residue sequence, yet Crystagen's sequence could not be confirmed from PubChem or the retrieved primary literature, and secondary designations conflict. Any structure-activity reasoning about it is therefore unfounded.
what’s reported
evidence shape
5 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
We could not confirm what Crystagen actually is. PubChem returns no compound record under the name, the retrieved primary abstracts describe it only as 'crystagen' without giving a sequence, and retail listings disagree — some give Glu-Asp-Pro (EDP), others Glu-Asp-Gly (EDG), which is the designation usually assigned to a different family member, Chonluten. On top of that unresolved identity, the biological record is the thinnest of the five: a small number of in vitro immunology papers from the originating group, one of which reports a null effect on cell renewal, with no animal outcome study, no human data and no registered trial. An immune-modulation claim built on this is unsupported, and a research reagent whose sequence cannot be verified against any public reference is unusable for rigorous work.
key published findings
- ClinicalTrials.gov contains no registered study of Crystagen (verified by registry query).
- No published human study of Crystagen was located, and the originating group's 2014 review of clinical results for its bioregulators does not include it.
- Sequence could not be verified: PubChem has no compound record under the name Crystagen, and the retrieved primary abstracts do not state a sequence — reported as null rather than guessed.
- Secondary and retail sources conflict, variously giving Glu-Asp-Pro (EDP) and Glu-Asp-Gly (EDG); EDG is the designation normally attributed to Chonluten, a different family member.
- In aged spleen culture, Crystagen was reported to activate B-cell immunity but explicitly to have no effect on cellular renewal — a negative result published by the originating group.
- All retrieved evidence is in vitro; no animal outcome model was identified.
- Formula, molar mass and CAS number are all unverifiable and reported as null.
limitations of the evidence
- Molecular identity unresolved — no verifiable sequence, formula, molar mass or CAS, which undermines every downstream claim.
- Smallest retrievable literature of the five compounds, entirely in vitro.
- Single-originator evidence base with no replication by any unaffiliated group.
- Key primary source is an English translation of a Russian journal (Advances in Gerontology / Uspekhi Gerontologii), a low-indexing venue.
- The group's own paper contains a null result for Crystagen on cell renewal, which is often omitted from secondary summaries.
- Sources are shared with the other Khavinson bioregulators in this index because these compounds are described in one common body of literature; shared reviews are not independent support.
documented safety signals
- No documented safety signals, and no published human safety data, toxicology or adverse-event surveillance of any kind.
- Absence of reported harm reflects absence of monitored human exposure.
- Unverifiable identity is itself a safety concern: with no authoritative chemical reference record and conflicting sequence designations in the market, the contents of a vial labelled 'Crystagen' cannot be confirmed.
identity
| full name | Crystagen (short peptide immune bioregulator; sequence unconfirmed) |
| category | Other |
| modality | peptide |
laboratory handling
| storage | Lyophilised powder is stored desiccated at -20 °C and protected from light. Once reconstituted, laboratory practice is refrigeration at 2-8 °C for short-term use, or aliquoting and freezing to avoid repeated freeze-thaw cycles. Handling information only; this compound has no approved human use. |
| solubility | Short hydrophilic peptide, readily soluble in sterile or bacteriostatic water and in dilute aqueous buffer. Lot-specific solubility is stated on the certificate of analysis. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
5 citedClinicalTrials.gov, US National Library of Medicine · 2026 · official
Advances in Gerontology (English translation of Uspekhi Gerontologii, Russian) · 2014 · review
Advances in Gerontology (English translation of Uspekhi Gerontologii, Russian) · 2014 · preclinical
Bulletin of Experimental Biology and Medicine (Russian translated journal) · 2002 · preclinical
Molecules · 2021 · systematic review
others in Other