Crystagen

Overview

Crystagen is a synthetic short-peptide "bioregulator" from the school of Vladimir Khavinson (St. Petersburg Institute of Bioregulation and Gerontology), marketed as an immune/thymic "Cytogen." Across the primary Khavinson literature and PubChem, its most consistent identity is the tripeptide Glu-Asp-Pro (EDP, glutamyl-aspartyl-proline), PubChem CID 145455337, molecular formula C14H21N3O8, molecular weight ~359.33 g/mol.

Its evidence base is characteristic of this class: older, mostly Russian, and largely preclinical — rodent aging models, and thymic-epithelial and lymphocyte cell cultures — with only small, uncontrolled or weakly-controlled Russian human immunogram reports. The proposed mechanism (short peptides binding gene-promoter/DNA sites to de-repress tissue-specific protein synthesis) is a hypothesis promoted by the originating group and is not independently established.

Crystagen is not FDA- or EMA-approved. It is a research reagent, not a medicine; the moment it is intended for human use it becomes an unauthorised medicine. This page describes what the literature reports while being candid about those limits.

Chemistry and structure

The exact molecular weight to full precision, and the salt/free-acid form as supplied, are not established in verifiable sources — PubChem gives ~359.33 for the free peptide.

Mechanism of action

The mechanisms below are drawn from the originating (Khavinson) group's work; note the evidence tier on each and read the overall picture as preliminary.

• Gene de-repression hypothesis. Short peptides of this class are proposed to interact complementarily with DNA / gene-promoter binding sites to de-repress tissue-specific protein synthesis (chromatin / RNA-polymerase activation). [Hypothesis] — model promoted by the originating group; not independently established. (Khavinson-group review, PMC8365293)
• Immunomodulation in vitro. Reported to stimulate lymphocyte proliferation/differentiation and cytokine secretion (IL-1, IL-6, TNFalpha) from peritoneal macrophages, and to activate proliferation of human thymic epithelial cells. [In vitro] — cell-culture data from Khavinson-group work. (PMC8365293)
• Age-associated immunoprotection. Reported immunoprotective effects in the spleen (B-cell activation) in aging rodent models. [Animal] — rodent aging models. (Advances in Gerontology, 2014)
• Immune normalization in patients. Claimed to restore/normalize immune parameters (immunogram, CD counts) in elderly patients. [Human] — small, mostly uncontrolled Russian clinical reports; not independently replicated. (PMC8365293)

Research and evidence

Human evidence. Limited and low-quality. Russian-language clinical reports cited in Khavinson-group reviews claim normalization of the immunogram in ~82% of elderly or senile immunity-impaired patients receiving Crystagen with standard therapy, versus ~56% in controls, plus increases in CD3+/CD4+ counts and a normalized CD4+/CD8+ ratio. These reports are small, mostly uncontrolled or weakly controlled, and single-school Russian data; they have not been independently replicated in peer-reviewed Western RCTs, and no registered trial (ClinicalTrials.gov / EU CTR) was found. Treat as preliminary/disputed, not established efficacy. There are no well-established human clinical trials and no verifiable human pharmacokinetics (half-life, bioavailability, oral vs injectable), validated dosing, or long-term safety data.

Status and regulation

• FDA / EMA. Not approved by the FDA or the EMA. No registered/verified clinical trials found.
• Russia. The Khavinson "Cytogen" peptides (including Crystagen) are marketed as dietary supplements / parapharmaceuticals rather than registered pharmaceuticals.
• Elsewhere. Sold only as a "research reagent / not for human use."
• Classification. An unauthorised / investigational substance the moment it is intended for human use.

There is no FDA or EMA regulatory record and no registered clinical trial for Crystagen that could be verified.

Safety

• No verifiable human safety data. Long-term safety, validated dosing, and human pharmacokinetics are not established in verifiable sources.
• Unreplicated evidence. The immune claims come from a single research school and have not been independently confirmed; safety cannot be inferred from that literature.
• Research-grade material. Product sold as a research reagent is not a regulated medicine and may differ in identity, purity, and sterility — compounded by the sequence ambiguity noted above (vendor sequences disagree with the primary record).
• Injection-related risks. Any injectable research powder carries the usual risks (local reactions, infection if non-sterile).

Legal status

Crystagen is best described by its regulatory classification, not by any notion of being "legal to take." It is not approved by the FDA or EMA; in Russia it is marketed as a supplement/parapharmaceutical; elsewhere it is sold only as a research reagent / not for human use. The absence of a specific ban is not affirmative permission — a compound becomes an unauthorised medicine the moment it is intended for human use. No source addresses any WADA sport-prohibition status for Crystagen, so none is stated here (sport eligibility is a separate axis from legality). This is not legal advice; laws differ by country and change over time — check your own jurisdiction. Information current as of 2026-07-08.

How it compares

• Thymalin — another Khavinson immune/thymic preparation, but a calf-thymus extract (a mixture) rather than a single defined peptide. It shares Crystagen's pattern of largely single-school, mostly-Russian evidence with limited independent replication.
• Epitalon — a synthetic Khavinson tetrapeptide (Ala-Glu-Asp-Gly) marketed for longevity; the same "short-peptide bioregulator" paradigm and the same caveat about single-group, sparsely-replicated evidence.
• Thymosin alpha-1 — by contrast, a single, fully defined 28-amino-acid peptide with a substantial independent international literature and approval as a medicine in a number of countries. It illustrates the gap between a well-characterised thymic peptide and a Khavinson "Cytogen" like Crystagen.

Common misconceptions

• "Crystagen's sequence is settled." It is not fully settled. The Khavinson literature and PubChem support Glu-Asp-Pro (EDP), but some vendor pages list Thr-Lys-Asp or Arg-Glu-Asp — sequences not supported by the primary record. Treat conflicting vendor sequences as unverified.
• "The immune benefits are proven in people." The human immunogram figures come from small, uncontrolled or weakly-controlled, single-school Russian reports that have not been independently replicated. They are preliminary, not established efficacy.
• "There's a known mechanism." The gene-de-repression model is a hypothesis from the originating group, not an independently established mechanism.
• "Not banned means it's legal to take." No specific ban is not affirmative permission. Intended for human use, it is an unauthorised medicine.
• "It has a CAS number." No CAS number is listed in PubChem's synonyms for CID 145455337; it is written here as Not established.