TB-500 is a synthetic peptide associated with the thymosin beta-4 (Tβ4) family. The name TB-500 generally refers to an N-acetylated heptapeptide corresponding to residues 17–23 of thymosin beta-4, with the sequence Ac-LKKTETQ. It has attracted research interest because this region is associated with actin-related cellular processes and tissue-repair biology. However, evidence for therapeutic benefits in humans remains limited, and TB-500 is not an FDA-approved medicine.
Key Points
Full name: TB-500
Related peptide: Thymosin beta-4
Peptide type: Synthetic heptapeptide
Length: 7 amino acids
Primary research areas: Tissue repair, cell migration, angiogenesis, inflammation, and cytoskeletal biology.
Proposed biological activity: The LKKTET region is associated with actin-binding activity and cellular processes involved in tissue remodeling.
Clinical evidence: Most evidence is preclinical; robust evidence demonstrating efficacy in humans is lacking.
Regulatory status: Investigational and not FDA-approved for injury recovery, muscle growth, wound healing, or other therapeutic indications.
Safety: Long-term human safety has not been adequately established.
Compounding concerns: FDA has identified potential concerns regarding immunogenicity and impurities associated with compounded TB-500 preparations.
Specifications
Chemical name: N-Acetyl-L-leucyl-L-lysyl-L-lysyl-L-threonyl-L-glutamyl-L-threonyl-L-glutamine
Sequence:Ac-LKKTETQ
Peptide length:7 amino acids
Parent peptide: Thymosin beta-4, a 43-amino-acid peptide.
Molecular formula:C₃₈H₆₈N₁₀O₁₄
Molecular weight: Approximately 889.0 g/mol for the N-acetylated form.
CAS number:885340-08-9
PubChem CID:62707662
UNII:QHK6Z47GTG
Chemical modification: N-terminal acetylation
Approved indication: None
Approved therapeutic dose: None established
Important: TB-500 should not be confused with full-length thymosin beta-4. They are chemically distinct molecules: TB-500 is the short heptapeptide fragment, whereas thymosin beta-4 contains 43 amino acids and has a molecular weight of roughly 4,963 Da.
