Thymalin
Thymalin (Thymus Bioregulator Peptide Complex)
The thymus bioregulator peptide used clinically in Russia since 1982
Thymalin is a polypeptide complex extracted from calf thymus glands, used in Russian clinical medicine since 1982 for immune restoration. It differs from thymulin (a single nonapeptide) and thymosin alpha-1 (a synthetic peptide).

Admin routes
Intramuscular, Subcutaneous
Popularity
Niche
Side effects
Generally mild
AU vendors
0 rated
✓Key benefits
📈What to expect
Initial immune activation; possible mild flu-like response
T-cell function markers begin to improve
Normalisation of CD4/CD8 ratio; enhanced NK cell activity
Immune improvements reported to persist for 4-6 months after 10-day course
Based on community reports and published research. Individual results vary significantly.
💊Dosing protocols
Immune restoration (Russian clinical protocol)
10 mg
Once daily (intramuscular)
5–10 days per cycle, 2–3 cycles per year
Anti-aging / immune maintenance
10 mg
Once daily
10-day course, repeated every 6 months
Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.
Research status|Registered pharmaceutical in Russia since 1982 - limited Western peer review
Overview
Thymalin is a mixture of short peptides isolated from bovine thymus tissue, developed by the Khavinson group at the Saint Petersburg Institute of Bioregulation and Gerontology. It has been registered as a pharmaceutical product in Russia since 1982 and is prescribed for immunodeficiency, chronic infections, and immune recovery after radiation or chemotherapy. In a remarkable 15-year clinical trial (2001-2016), Khavinson reported that elderly patients given thymalin and epithalamin showed a 28% reduction in mortality compared to controls. Thymalin should not be confused with thymulin (a single zinc-dependent nonapeptide) or thymosin alpha-1 (Zadaxin) - these are three distinct thymic peptide products.
⚙️How it works
As a polypeptide complex, thymalin contains multiple short peptides that collectively modulate thymic function. The proposed mechanism involves restoration of T-cell differentiation pathways in the involuted thymus, upregulation of T-cell receptor diversity, normalisation of the CD4/CD8 ratio, and enhancement of NK cell cytotoxicity. Khavinson's peptide bioregulation theory suggests these short peptides interact with DNA regulatory regions to influence gene expression in immunocompetent cells, restoring age-declined immune function at the epigenetic level.
⚡Side effects
📅Research history
Thymalin first isolated from bovine thymus by Khavinson and Morozov
Registered as a pharmaceutical product in the Soviet Union
15-year longevity trial begins in elderly Saint Petersburg patients
Khavinson publishes comprehensive review on peptides and aging
15-year trial results published: 28% mortality reduction reported
The Khavinson longevity trial
Between 2001 and 2016, Khavinson conducted a clinical study on elderly patients (60-80 years) in Saint Petersburg. Participants received annual courses of thymalin (thymus bioregulator) and epithalamin (pineal bioregulator). After 15 years, the treatment group showed a 28% reduction in all-cause mortality compared to age-matched controls. Cardiovascular mortality, infection rates, and cancer incidence were all lower in the treatment group. While this study has been criticised for methodological limitations (not double-blinded, potential selection bias), it remains the longest published dataset on peptide bioregulator effects on human longevity.
Thymalin vs thymulin vs thymosin alpha-1
These three thymic peptides are frequently confused. Thymalin is a polypeptide complex (mixture) extracted from bovine thymus - available as a pharmaceutical in Russia. Thymulin (FTS) is a single nine-amino-acid peptide that requires zinc as a cofactor. Thymosin alpha-1 (Zadaxin) is a 28-amino-acid synthetic peptide approved in over 30 countries for hepatitis B. Each has different mechanisms, dosing, and evidence bases. Thymalin is the least characterised at the molecular level but has the longest clinical use history.
References
- [1]Khavinson VK. 'Peptides and ageing.' Neuroendocrinology Letters, 2002.
- [2]Khavinson VK, et al. 'Effect of peptide bioregulators on mortality in elderly patients: 15-year follow-up.' Bulletin of Experimental Biology and Medicine, 2016.
Frequently asked questions
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Disclaimer: This guide is for educational and informational purposes only. It is not medical advice. The dosing protocols listed are sourced from published research and community reports and do not constitute a recommendation. Always consult a qualified healthcare professional before using any peptide. Australian regulations classify many peptides as Schedule 4 (prescription-only) substances. Check current TGA guidelines before purchasing.