Thymalin

Overview

Thymalin is a heterogeneous polypeptide extract from calf thymus (a mixture, not a single defined peptide) developed in the 1970s by V. Kh. Khavinson and V. G. Morozov at the Military Medical Academy / St. Petersburg Institute of Bioregulation and Gerontology. Registered as a pharmaceutical in the USSR/Russia for immunocorrection. Distinct from Thymulin (Bach's zinc-dependent nonapeptide pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, originally called FTS) and from Thymosin alpha-1 (a 28-amino-acid synthetic peptide). Not FDA-approved in the US; research-use only.

Mechanism of Action

Claimed to restore T-lymphocyte subset differentiation and modulate cytokine and neutrophil function. Short peptide fragments from the extract (notably Glu-Trp and Lys-Glu) are proposed to enter cells and influence gene expression. Mechanistic data come almost entirely from the Khavinson group and have not been independently replicated in Western pharmacology literature.

Research Summary

Evidence base is almost entirely single-lab (Khavinson/Morozov, St. Petersburg). Long-term observational work in elderly Russian cohorts reported reduced all-cause mortality and lower incidence of respiratory infections with Thymalin (alone or with Epithalamin) over 6–8 years, but these were not blinded Western RCTs and have not been independently reproduced. No FDA-registered clinical trials.

Dosing Information

Reported Side Effects

• Injection site reactions
• Rare allergic / hypersensitivity reactions (bovine-derived extract)

Research References

• Khavinson & Morozov — Peptides of pineal gland and thymus prolong human life (Neuro Endocrinol Lett) (2003)
• Khavinson & Morozov — Geroprotective effect of thymalin and epithalamin (Adv Gerontol, Russian) (2002)
• Khavinson et al. — The Use of Thymalin for Immunocorrection and Molecular Aspects of Biological Activity (Biol Bull Rev) (2021)
• Khavinson, Kuznik, Ryzhak — Peptide bioregulators: clinical studies results (Adv Gerontol, Russian) (2013)