Quick Comparison
| Crystagen | Thymalin | |
|---|---|---|
| Half-Life | Approximately 30 minutes (acute pharmacology); proposed gene-expression effects outlast plasma exposure | Variable (complex peptide mixture; estimated several hours) |
| Typical Dosage | Oral (capsule): 100-200 mg once daily for 10-30 day cycles, repeated 2-3 times per year. Subcutaneous injection: 1-5 mg per dose, alternate days for 10-20 day cycles. Standard Khavinson cycling protocol. | Standard: 10 mg intramuscular once daily for 5-10 days. Cycled once or twice yearly for immune support. Some protocols use 10-day courses at the start of cold/flu season. |
| Administration | Oral capsule or subcutaneous injection (cycled) | Intramuscular injection |
| Research Papers | 1 papers | 3 papers |
| Categories |
Mechanism of Action
Crystagen
Crystagen is a short Khavinson tripeptide (Glu-Asp-Pro) positioned as the immune and thymus-targeted bioregulator within the wider Khavinson peptide family. The proposed mechanism follows the standard family framework: short peptides interact with gene promoter sequences in thymic and lymphocyte cell nuclei, modulating expression of genes involved in T cell maturation, cytokine production, and broader immune regulation.
Proposed effects include support for thymic function — particularly relevant given the well-documented age-related thymic involution that contributes to immunosenescence in older adults — alongside modulation of lymphocyte chromatin organisation and immune cell maturation pathways. Russian research has reported crystagen-induced improvements in lymphocyte counts, T helper cell function, and clinical recovery from infections in elderly populations and in patients recovering from immunosuppressive treatments. The peptide is often used alongside thymalin (a related thymic peptide preparation also in this database) as part of broader Khavinson immune-support protocols.
As with the rest of the Khavinson family, the efficacy evidence base sits within Russian gerontology and immunology research with limited independent Western validation. Crystagen is not validated as a treatment for primary immunodeficiency, HIV-related immune dysfunction, or other formally diagnosed immune conditions, and should not displace evidence-based immune therapy. The brief plasma half-life (around 30 minutes) reflects the proposed model of transient signalling triggering longer-lasting transcriptional changes in immune cell populations.
Thymalin
Thymalin is a complex of short peptides extracted from bovine thymus glands, representing the biologically active fraction of thymic hormones. The thymus gland is the primary organ of T-cell maturation — bone marrow-derived T-cell precursors migrate to the thymus where they undergo positive and negative selection, emerging as mature, immunocompetent CD4+ helper and CD8+ cytotoxic T cells. The thymus produces a suite of peptide hormones that guide this maturation process, and Thymalin contains a mixture of these bioactive peptides.
The peptide complex acts at multiple points in the immune system. It promotes the differentiation of pre-T cells into mature T-cell subsets, restoring the CD4/CD8 ratio toward normal values (typically 1.5-2.5:1 in healthy individuals). It enhances natural killer (NK) cell cytotoxic activity, which is critical for immune surveillance against virus-infected and neoplastic cells. It modulates cytokine production — generally promoting a balanced Th1/Th2 response rather than driving either extreme — and enhances macrophage phagocytic capacity.
The relevance to aging is direct: the thymus undergoes progressive involution (shrinkage) beginning at puberty, and by age 60-70, most thymic tissue has been replaced by fat, with minimal residual T-cell educating capacity. This thymic involution is a major driver of immunosenescence — the age-related decline in immune function that increases susceptibility to infections, cancers, and autoimmune conditions while reducing vaccine responsiveness. Thymalin aims to pharmacologically replace the thymic peptide signals lost through involution, partially restoring the immune system's ability to produce new, functional T cells. Research from the Khavinson group has reported that Thymalin treatment in elderly patients was associated with reduced mortality and improved immune markers over long-term follow-up, though these studies require independent replication in Western clinical settings.
Risks & Safety
Crystagen
Common
generally reported as well tolerated.
Serious
very limited Western clinical data; theoretical concern with use in autoimmune disease (immune-modulating peptides may unpredictably affect autoimmune activity).
Rare
allergic reactions. Should not replace evidence-based immune therapy in serious immunodeficiency.
Thymalin
Common
pain and reactions at the injection site, mild fatigue during the first course.
Serious
limited Western clinical data, most evidence comes from Russian institutions.
Rare
severe allergic reaction, may trigger autoimmune activity in predisposed individuals.
Full Profiles
Crystagen →
A Khavinson tripeptide (Glu-Asp-Pro) developed in Russia as a tissue-specific bioregulator targeting the thymus and broader immune system. Promoted for age-related immune decline (immunosenescence), recovery from immunosuppressive treatments, and as a general immune support during the cold and flu season. Within the same Khavinson family as thymalin and thymosin alpha-1, both already in your database.
Thymalin →
A peptide blend extracted from the thymus glands of young animals. The thymus is the gland that helps train your immune cells. This preparation supports thymus activity and helps your body mature T-cells — the immune cells that fight infections and cancer. It's been used in Russian medicine for decades, though Western clinical evidence is still limited.