Thymosin Beta-4 Fragment (TB4-Frag)
Thymosin Beta-4 Fragment (Ac-SDKP)
The N-terminal tetrapeptide fragment of Thymosin Beta-4, Ac-SDKP is a potent anti-fibrotic and anti-inflammatory peptide with unique stem cell mobilization properties. Distinct from full TB4, it specifically targets fibrosis and chronic inflammation.
Mechanism of Action
Ac-SDKP (N-acetyl-seryl-aspartyl-lysyl-proline) is released from Thymosin Beta-4 by prolyl oligopeptidase. It inhibits TGF-β1-induced fibroblast activation and collagen synthesis, reducing fibrosis in cardiac, renal, and hepatic tissue. It mobilizes hematopoietic stem cells from bone marrow, promotes angiogenesis, and inhibits macrophage-driven inflammation by suppressing NF-κB. It also inhibits T-cell and B-cell proliferation in hyperactivated immune states, making it useful for autoimmune and fibrotic conditions.
Health Claims & Evidence
Anti-fibrotic — reduces cardiac, renal, and hepatic fibrosis
Mobilizes hematopoietic stem cells for tissue repair
Suppresses chronic inflammation via NF-κB inhibition
Promotes angiogenesis and tissue vascularization
Reduces autoimmune T-cell and B-cell hyperactivation
Short-Term Effects
Reduced inflammatory markers, improved tissue repair, decreased fibrotic progression.
Long-Term Effects
Prevention of organ fibrosis, sustained anti-inflammatory immune balance, improved tissue vascularization.
Side Effects
Well-tolerated in research. No significant adverse effects documented at therapeutic doses.
Contraindications
Limited human data. Theoretical caution in active malignancy due to angiogenic and stem cell mobilization effects.
This profile is provided for educational research only. It is not a treatment recommendation or dosing guide. Human evidence, safety information and regulatory status vary by substance. Verify primary sources and consult a qualified healthcare professional for medical decisions.
Research Papers
Ac-SDKP inhibits TGF-β1-induced cardiac fibrosis
Peng H et al. · Hypertension · 2003
N-acetyl-seryl-aspartyl-lysyl-proline prevents cardiac remodeling
Rhaleb NE et al. · Circulation · 2001
Ac-SDKP mobilizes hematopoietic progenitor cells
Lenfant M et al. · Proceedings of the National Academy of Sciences · 1996
Educational research only. This profile is not a treatment recommendation or dosing guide. Human evidence, safety information and regulatory status vary by substance. Consult a qualified healthcare professional for medical decisions.
Related Peptides
Explore the research further
Our AI Research Advisor can help you explore the evidence on Thymosin Beta-4 Fragment (TB4-Frag) and related peptides, and prepare an educational research summary.
Explore Research