Immune · Research Phase
Bursin
No lawful US pathway
01 · Overview
Bursin is a tripeptide amide (Lys-His-Gly-NH2) originally isolated from the bursa of Fabricius in chickens, where it was described as a selective B-cell-differentiating hormone (PMID 3484838). The same peptide was later reported in avian and bovine bone marrow and in bovine liver (PMID 2408136).
Its proposed therapeutic rationale is to selectively enhance humoral (antibody-based) immunity.
02 · Research summary & key findings
In vitro, bursin induced differentiation of avian and mammalian B-cell precursors but not T-cell precursors (PMID 3484838). However, a later study found that bursin and a reverse-sequence control tripeptide had similar effects, suggesting it enhances B-cell precursor differentiation in a non-specific way rather than acting as a lineage-specific hormone (PMID 2788513). Synthetic bursin increased B lymphocytes from uremic patients in cell culture (PMID 8608325), but no controlled human trials have been reported.
03 · Regulatory status
Bursin is in the research phase with limited clinical data in humans. Current evidence is primarily derived from preclinical (animal or in vitro) studies.
No lawful pathway today
Bursin is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so we do not sell it and will not book a consultation for it. That can change: in 2026 FDA began reviewing several peptides for compounding.
See the 1 FDA-approved compound in Immune
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04 · Administration routes
- Subcutaneous injection
References
- [1]Bursin localization in mammalian bone marrow and epithelial cells of intrahepatic bile ducts Scand J Immunol, 1990. PMID 2408136
- [2]A role for Lys-His-Gly-NH2 in avian and murine B cell development Cell Immunol, 1989. PMID 2788513
- [3]Tripeptide structure of bursin, a selective B-cell-differentiating hormone of the bursa of fabricius Science, 1986. PMID 3484838
- [4]Syntheses and effect of bursin and it analogs on the reduced B lymphocytes of uremic patients Biotechnol Ther, 1994. PMID 8608325
Primary literature
- PubMed: "Bursin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Bursin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Bursin"
Chemical structure, molecular properties, and bioactivity data.
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