Peptides Academy
Thymulin
Research-Grade
Thymulin (formerly called facteur thymique sérique, FTS) is a nonapeptide hormone produced by epithelial cells of the thymus. Its biological activity depends on a bound zinc ion: without zinc it is inactive. Early work by Bach and Dardenne showed that zinc-thymulin induces T-cell differentiation and enhances the functions of several T-cell subsets in animals with normal or partly deficient thymus function. In healthy people, plasma thymulin rises through childhood, peaks at about 5–10 years of age, falls from adolescence, and reaches its lowest level around age 36, then stays steady to at least 80. Zinc status matters: in human volunteers on an experimental zinc-deficient diet, thymulin activity fell within 8–12 weeks, before plasma zinc dropped, and a small pilot study in very old people found zinc-fortified milk increased thymulin activity. Zinc supplementation in people who are deficient is the evidence-based way to support thymulin activity. As a therapy, thymulin remains experimental. Reviews describe anti-inflammatory and analgesic effects of thymulin and a synthetic analogue (PAT) in rodent models, and gene-therapy studies restoring thymulin in thymus-deficient mice. A 2026 mouse and human-cell study found thymulin suppressed age-associated inflammatory myeloid cells by inhibiting NF-κB and improved responses to anti-PD-L1 cancer immunotherapy in aged mice. No randomized human trial of synthetic thymulin has been published that we could verify, and the FDA has placed thymulin acetate among compounding substances nominated without adequate support.
Specifications
| Origin / Manufacturer | Synthetic (identical to endogenous) |
| Active Components | Thymulin nonapeptide (zinc-bound active form) |
| Storage | Follow the supplier's label; no validated stability data published |
| Form Factor | Lyophilized powder (research-chemical market) |
Frequently Asked Questions
Sources & References
Every clinical claim on this page traces to a primary peer-reviewed source.
- 1Bach JF, Dardenne M. Thymulin, a zinc-dependent hormone. Medical oncology and tumor pharmacotherapy. 1989;6(1):25-9. doi:10.1007/BF02985220 PMID:2657247
- 2Reggiani PC, Schwerdt JI, Console GM, et al.. Physiology and therapeutic potential of the thymic peptide thymulin. Current pharmaceutical design. 2014;20(29):4690-6. doi:10.2174/1381612820666140130211157 PMID:24588820
- 3Consolini R, Legitimo A, Calleri A, et al.. Distribution of age-related thymulin titres in normal subjects through the course of life. Clinical and experimental immunology. 2000;121(3):444-7. doi:10.1046/j.1365-2249.2000.01315.x PMID:10971509
- 4Prasad AS. Lessons Learned from Experimental Human Model of Zinc Deficiency. Journal of immunology research. 2020;2020:9207279. doi:10.1155/2020/9207279 PMID:32411807
- 5Saha AR, Hadden EM, Hadden JW. Zinc induces thymulin secretion from human thymic epithelial cells in vitro and augments splenocyte and thymocyte responses in vivo. International journal of immunopharmacology. 1995;17(9):729-33. doi:10.1016/0192-0561(95)00061-6 PMID:8582784
- 6Costarelli L, Giacconi R, Malavolta M, et al.. Effects of zinc-fortified drinking skim milk (as functional food) on cytokine release and thymic hormone activity in very old persons: a pilot study. Age (Dordrecht, Netherlands). 2014;36(3):9656. doi:10.1007/s11357-014-9656-x PMID:24771015
- 7Mocchegiani E, Santarelli L, Costarelli L, et al.. Plasticity of neuroendocrine-thymus interactions during ontogeny and ageing: role of zinc and arginine. Ageing research reviews. 2006;5(3):281-309. doi:10.1016/j.arr.2006.06.001 PMID:16904953
- 8Safieh-Garabedian B, Mayasi Y, Saadé NE. Targeting neuroinflammation for therapeutic intervention in neurodegenerative pathologies: a role for the peptide analogue of thymulin (PAT). Expert opinion on therapeutic targets. 2012;16(11):1065-73. doi:10.1517/14728222.2012.714773 PMID:22861065
- 9Kanemaru H, Luong S, Yamamoto Y, et al.. Thymulin restrains age-associated myeloid inflammation and enhances cancer immunotherapy. Nature communications. 2026;17(1). doi:10.1038/s41467-026-75383-0 PMID:42481458
- 10U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (updated May 14, 2026). U.S. Food and Drug Administration. 2026.
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