Summary
Thymalin is a mixture of polypeptides extracted from calf thymus, registered in Russia as an immune-modulating medicine. Research led by Khavinson and Morozov reported improved immune markers and lower mortality in older adults over long follow-up, in studies that have not been independently replicated.
How it works
Proposed to restore T-cell function and thymic hormone balance in immune deficiency. As a mixture, its active components are not fully defined; the dipeptide thymogen (Glu-Trp) is described as one of them.
Research use cases
Areas where Thymalin has been studied. Inclusion here does not mean it works for that purpose.
- Immune deficiency
- Ageing research
What the research found
Long-term elderly cohort
Khavinson and Morozov reported that older adults treated with thymalin and the pineal preparation epithalamin had lower mortality over six to eight years than controls. The studies were small and not blinded by modern standards.1
Safety and open questions
Russian clinical use reports few side effects. Biological extracts carry batch-to-batch variability.
Regulatory status
Registered in Russia as a medicine. Not approved in the US or EU.
Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.
Thymalin: common questions
Is thymalin the same as thymosin alpha-1?
No. Thymalin is an undefined mixture from calf thymus. Thymosin alpha-1 is a single defined 28-residue peptide.
Is Thymalin approved for human use?
Registered in Russia as a medicine. Not approved in the US or EU.
References
- Khavinson VKh, Morozov VG. (2003). Peptides of pineal gland and thymus prolong human life. Neuro Endocrinology Letters.
Links open a PubMed search for the exact title, or the original source where one is given.