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.

Russian research

Much of the evidence for Crystagen (the tripeptide EDP, Glu-Asp-Pro) comes from a single Russian research lineage — V.Kh. Khavinson and the St. Petersburg Institute of Bioregulation and Gerontology — and is surfaced here for completeness. It is framed honestly: the body of work is small, largely patent-derived, single-group, and not independently replicated outside Russia.

• [In vitro] Thymic-epithelial-cell proliferation. The patented peptide H-Glu-Asp-Pro-OH (EDP / Crystagen) significantly increased proliferation of human thymic epithelial cells (VTEC2.H/S line, passage 7) at 2, 20 and 200 ng/ml, with the largest effect at 200 ng/ml (~52% over control: 795±49 vs 523±32 cells), presented by the inventors as the basis of an "immunogeroprotective effect." Source: US Patent 8,057,810 B2 (Khavinson, Grigoriev, Malinin, Ryzhak; assignee at grant SIA Peptides; granted 2011-11-15; https://patents.google.com/patent/US8057810B2/en (opens in a new tab)). This is the primary source that vendor pages paraphrase as "stimulates thymic epithelial cell proliferation" — it is a patent, not a peer-reviewed study, and is in-vitro cell-line data only, not clinical evidence.

• [Animal] Age-related immunomodulation in spleen (best peer-reviewed item, with a partly null result). In an aging rat-spleen model comparing four peptides (vilon, thymogen, crystagen, R-1), crystagen was reported to activate B-cell immunity in the spleen but to have NO effect on cellular-renewal (proliferation/apoptosis balance) processes during aging — i.e. a partial, limited effect relative to the other peptides. This partly-null finding is an honest counter-signal and is preserved here rather than smoothed over. Source: Chervyakova N.A., Lin'kova N.S., Chalisova N.I., Kontsevaya E.A., Trofimova S.V., Khavinson V.Kh., "Age-related molecular aspects of immunomodulating activity of peptides in the spleen," Advances in Gerontology 2014, 4(1):12–15, DOI 10.1134/S2079057014010020. No PubMed PMID was located (this Springer-translated journal is not consistently PubMed-indexed); the DOI is the verifiable identifier. Small comparative animal study, single originating group.

• [Human] Immunogram normalization in elderly patients — a patent-level claim, NOT a controlled trial. Russian-language/patent sources describe Crystagen plus standard treatment normalizing the immunogram in ~82% of elderly/senile patients with impaired immunity versus ~56% in controls, with a greater effect on T-cell immunity (rise in CD3+ and CD4+ cells, normalization of the CD4+/CD8+ ratio) than on B lymphocytes. This single most-cited "human" figure traces to a Russian PATENT — RF Patent 2301074 (Khavinson et al., 2006) — reproduced in the group's own open-access review (PMC8365293, ref. 17; https://pmc.ncbi.nlm.nih.gov/articles/PMC8365293/ (opens in a new tab)), and NOT to a peer-reviewed randomized controlled trial. No sample size, randomization, blinding, or independent replication is verifiable, so this must be read as report/patent-level evidence, not established clinical efficacy. The full text of RF Patent 2301074 was not independently retrieved; only its claim as reproduced in the open-access review was verified. The same source also reports [Animal/In vitro] that EDP stimulated peritoneal-macrophage secretion of IL-1, IL-6 and TNF-alpha in young and old mice — likewise of patent origin from the same group.

• [In vitro] Spleen organotypic explant culture (traceable, but no standalone identifier). EDP (Glu-Asp-Pro), alongside the peptides EW (Glu-Trp) and KE (Lys-Glu) and compared to whole thymalin, was reported to increase the spleen-explant growth-zone/area index by ~20–50% and reduce cell apoptosis by ~29–42% versus control in young and old rats, with an effect weaker than whole thymalin. This finding is traceable to the open-access review PMC8365293 (cited there to refs. 6–8, Chalisova/Ryzhak et al., 2011–2017), but a single clean standalone DOI/PMID for this exact EDP-peptide spleen study was NOT isolated, so it is anchored to the review rather than asserted with an independent citation; no DOI is invented here. (A nearby 2012 Bulletin of Experimental Biology and Medicine paper, DOI 10.1007/s10517-012-1769-6, "Effect of Amino Acids on Expression of Signal Molecules in Organotypic Culture of the Spleen," tests free amino acids in spleen culture, not the EDP peptide, and is not the same study.)

• [Review] Open-access anchor. Khavinson V.Kh. et al., "The Use of Thymalin for Immunocorrection and Molecular Aspects of Biological Activity," Biology Bulletin Reviews 2021 (DOI 10.1134/S2079086421040046; PMC8365293) aggregates the EDP/Crystagen claims above (immunogram normalization, macrophage cytokines, thymic epithelial proliferation). It is authored by the originating group, so it is not independent evidence; its value is transparency — it lets each underlying claim be traced back to its patent origin.

Unverifiable / cautioned: the human immunogram trial parameters behind "~82% vs ~56%" (sample size, recruitment, randomization, blinding, duration) are not verifiable; no open-access CyberLeninka primary study on Crystagen specifically was located; and human pharmacokinetics, validated dosing and long-term safety are not established in any verifiable source. Note also that a widely-cited MDPI THP-1 macrophage study (PMID 35408963 / DOI 10.3390/ijms23073607) tests other Khavinson peptides (Epitalon, Vilon, Thymogen, Thymalin, Chonluten), NOT EDP/Crystagen, and must not be cited as Crystagen evidence.

On quality: the Crystagen evidence base is weak and characteristic of the Khavinson class — small, older, single-group (St. Petersburg Institute of Bioregulation and Gerontology), preclinical/patent-dominant, with one small peer-reviewed animal study whose result is partly null, no human RCT, no independent Western replication, and no human PK. Its Russian status — sold as a dietary supplement / parapharmaceutical ("Cytogen" bioregulator), explicitly "не является лекарственным средством" (not a medicinal product) and used only alongside main treatment — is a regulatory and commercial fact, not proof of efficacy, and is not the same as being registered as a medicine. Outside Russia it is not FDA- or EMA-approved and is sold only as a research reagent, not for human use; no registered clinical trial (ClinicalTrials.gov / EU CTR) was located.