Thymalin

What it is

Thymalin is a polypeptide preparation obtained from calf thymus by mild acid extraction, developed in the Soviet Union by Morozov and Khavinson and studied there since the early 1980s. It has been used clinically in Russia as an immunomodulator and appears in Russian immunology and gerontology research. It is not approved by the FDA or the EMA, and most of its literature is published in Russian by the group that developed it.

How it works

Thymalin is a mixture of short peptides, and its developers report that it promotes T-cell differentiation and modulates cytokine release. The dipeptides Lys-Glu and Glu-Trp have been named as active components, but no mechanism has been established in independent research.

Regulatory status

1. Cosmetic ingredient
2. Research compound
3. In clinical trials
4. Approved medicine

Not approved as a medicine by the FDA or the EMA. Some are registered in individual countries. Supplied for laboratory research only.

What published research is studying

• T-cell differentiation and cytokine release in human cell culture
• Mortality and age-related disease in elderly cohorts given courses over several years
• Add-on use in hospitalised patients with severe COVID-19
• Blood coagulation and immune markers in burns and other inflammatory conditions, mostly in Russian-language reports

Key findings

1. 01

   In a 6 to 8 year observation of 266 elderly people reported by the developers, those given Thymalin during the first 2 to 3 years had a 2.0 to 2.1-fold lower mortality rate than controls; the abstract gives little detail on how groups were allocated.

   Khavinson VKh and Morozov VG, Neuro Endocrinol Lett 2003
2. 02

   In a Russian-language report on middle-aged and elderly patients hospitalised with severe COVID-19, in-hospital mortality was 40.9% with basic therapy, 28.4% with added tocilizumab and 20.6% with added Thymalin; group sizes and allocation method are not stated in the abstract.

   Kuznik BI et al., Adv Gerontol 2022
3. 03

   In a Russian-language comparative report on 32 patients with third and fourth degree burns, adding Thymalin was associated with first skin grafting about 5 days earlier and a hospital stay 11 days shorter.

   Kuznik BI et al., Vestn Khir Im I I Grek 2000
4. 04

   In cultured human haematopoietic stem cells, Thymalin lowered expression of the stem cell markers CD44 and CD117 by 2 to 3 times and raised expression of the mature T-cell marker CD28 by 6.8 times.

   Khavinson VK et al., Bull Exp Biol Med 2020
5. 05

   In lipopolysaccharide-stimulated blood mononuclear cells from four donors, Thymalin and its Lys-Glu and Glu-Trp dipeptides lowered IL-1 beta, IL-6 and TNF-alpha production by 1.4 to 6.0 times.

   Linkova N et al., Int J Mol Sci 2023

How strong is the evidence?

Common questions