Thymogen
A two-amino-acid peptide isolated as the active fragment of thymalin. Registered in Russia; no Western trials exist.
Immune & Inflammation
Thymalin
A thymus-derived peptide preparation from the Soviet-era Khavinson research programme, used clinically in Russia. Almost all evidence is Russian-language and unreplicated.
Overview
The thymus is where T cells mature, and it shrinks steadily with age — a change that tracks the decline in immune function. Thymalin is an extract of calf thymus containing a mixture of short peptides, developed on the premise that supplying those signals restores T-cell maturation. Russian studies report effects on immune markers and, in one much-cited long-term follow-up, on mortality in elderly participants. That work has never been independently replicated.
A polypeptide fraction extracted from bovine thymus, comprising peptides largely below 10 kDa. Reported to promote thymocyte differentiation, normalise CD4/CD8 ratios, increase T-lymphocyte counts and modulate interleukin production. It is the parent preparation from which the synthetic dipeptide thymogen (Glu-Trp) was derived. A widely cited Khavinson follow-up study reported reduced mortality over 6–8 years in elderly participants given repeated courses of thymalin, with or without epithalamin. Methodological detail in the available English-language reports is limited and there is no independent replication.
Research areas
ImmunosenescenceThymic functionGeroprotection
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| 10 mg intramuscularly daily for 5–10 days as a course | Russian registered protocol |
| Repeated annual courses in elderly participants with long-term mortality follow-up | Khavinson et al., Neuroendocrinology Letters 2002 |
Trial status
Russian clinical studies including long-term geroprotective follow-up. No Western trials and no independent replication.
Reported safety signals
- A bovine tissue-derived biological, so hypersensitivity and, in principle, transmissible agent concerns apply.
- Batch composition is not standardised in the way a synthetic peptide is.
- The geroprotection claims rest on studies from a single research group without independent replication.
- Not available through regulated channels outside Russia.
Common questions
How does thymalin differ from thymosin alpha-1?
Thymosin alpha-1 is a single, defined 28-amino-acid synthetic peptide approved in several countries with published international trials. Thymalin is an undefined bovine extract with a variable peptide composition and a Russian-only evidence base. They are not interchangeable.
Primary sources
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
How this profile was built →