--- title: "Tuftsin" canonical_url: https://bestpeptidecalculator.app/library/tuftsin description: "Naturally occurring tetrapeptide derived from the Fc region of immunoglobulin G, studied for effects on phagocytes. It is the structural parent of Selank. Not FDA-approved." updated: 2026-11-07 publisher: Peptide Library notice: "Research and educational use only. Not medical advice." --- # Tuftsin Tuftsin is an endogenous immunostimulatory tetrapeptide in the Immune Modulator class. Tuftsin is released by enzymatic cleavage of the IgG heavy chain and binds receptors on neutrophils, monocytes and macrophages, where it has been reported to stimulate phagocytosis, chemotaxis and antigen presentation. Naturally occurring tetrapeptide derived from the Fc region of immunoglobulin G, studied for effects on phagocytes. It is the structural parent of Selank. Not FDA-approved. Categories: Experimental. ## Classification - Type: Endogenous immunostimulatory tetrapeptide - Mechanism class: Immune Modulator - Development stage: Research only - Regulatory class: Research compound, not FDA-approved ## Mechanism Tuftsin is released by enzymatic cleavage of the IgG heavy chain and binds receptors on neutrophils, monocytes and macrophages, where it has been reported to stimulate phagocytosis, chemotaxis and antigen presentation. Its very short plasma half-life is the main obstacle to therapeutic use and the reason stabilised analogs such as Selank were developed. ## Properties - Sequence: Thr-Lys-Pro-Arg - Length: 4 - Molecular formula: C21H40N8O6 - Molecular weight: 500.6 g/mol ## Evidence - Evidence level: Preclinical Evidence - Highest documented: Lab & animal studies - Human trials: 0 - Controlled human trials: 0 - Preclinical sources: 2 - Latest source: 2025 No human dose is established for this compound. Each step shows whether the sources Peptide Library has reviewed include that kind of research. Counts are reviewed sources, not every study ever published. Reviews and programme summaries that describe human use are shown as "reported", not as trials, and registered trials without published results are listed but not counted. A higher step means research has progressed further; it does not mean a compound works better or is safer. Compounds whose evidence has not been reviewed yet show "Not reviewed" instead of a guess. ### Studies 1. Tuftsin: its chemistry, biology, and clinical potential. Crit Rev Biochem Mol Biol. 1989. 1989. Preclinical: animal or lab study. Population: Not applicable (review of laboratory and animal work). Describes stimulation of phagocytosis, movement and killing activity of macrophages, and low toxicity. Limitations: Lab or animal research: not evidence of a human effect or dose. [Source](https://pubmed.ncbi.nlm.nih.gov/2667894/) 2. FcγR-targeted tuftsin clusters rejuvenate macrophages in preclinical sepsis-associated secondary infection. Sci Transl Med. 2025. 2025. Preclinical: animal or lab study. Population: Mice with sepsis and secondary lung infection. Better survival and macrophage function reported with the nanoparticle. Limitations: Lab or animal research: not evidence of a human effect or dose. [Source](https://pubmed.ncbi.nlm.nih.gov/41442500/) ## Safety Human safety basis: No controlled human safety data Key limitations: No established human dosage.; No controlled human trial results in the reviewed sources.; Not approved by the FDA for any use.. ## Regulatory status Tuftsin is not an FDA-approved product. It is sold for laboratory research and has no approved medical use. - FDA status: Not Approved - Availability: Research-Only ## Frequently asked questions ### What is Tuftsin? Naturally occurring tetrapeptide derived from the Fc region of immunoglobulin G, studied for effects on phagocytes. It is the structural parent of Selank. Not FDA-approved. ### How does Tuftsin work? Tuftsin is released by enzymatic cleavage of the IgG heavy chain and binds receptors on neutrophils, monocytes and macrophages, where it has been reported to stimulate phagocytosis, chemotaxis and antigen presentation. Its very short plasma half-life is the main obstacle to therapeutic use and the reason stabilised analogs such as Selank were developed. ### Is Tuftsin FDA approved? No. Tuftsin is not approved by the FDA for any indication and is categorised as research-only. It has not been reviewed for safety or efficacy as a medicine, and published research should be read as investigation rather than established use. ### What is the amino acid sequence of Tuftsin? Tuftsin has the sequence Thr-Lys-Pro-Arg, giving a chain of 4 amino acids. Its molecular formula is C21H40N8O6. ### What peptides are similar to Tuftsin? Compounds most often compared with Tuftsin include Selank, N-Acetyl Selank Amidate, Semax and Noopept. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ. ## References - [Helminth derivative tuftsin-phopshorylcholine to treat autoimmunity — Autoimmun Rev, 2024](https://pubmed.ncbi.nlm.nih.gov/39159711/) - [Tuftsin phosphorylcholine-a novel compound harnessing helminths to fight autoimmunity — Immunol Res, 2018](https://pubmed.ncbi.nlm.nih.gov/30554380/) - [Tuftsin - Properties and Analogs — Curr Med Chem, 2017](https://pubmed.ncbi.nlm.nih.gov/28745220/) - [FcγR-targeted tuftsin clusters rejuvenate macrophages in preclinical sepsis-associated secondary infection — Sci Transl Med, 2025](https://pubmed.ncbi.nlm.nih.gov/41442500/) - [The P2X7-Mediated Mitochondrial ROS as an Emerging Core Target of Tuftsin Nanoparticles in Severe Acute Pancreatitis Therapy via Regulating Mitophagy — ACS Appl Mater Interfaces, 2025](https://pubmed.ncbi.nlm.nih.gov/39854589/)