← Shelf·Thymosin β-4 fragment·X.
TB-500.
A synthetic peptide corresponding to the acetylated N-terminal fragment of thymosin β-4 (TMSB4X), a 43-amino-acid actin-binding protein originally isolated from thymic tissue. Characterized by Allan Goldstein and colleagues at George Washington University, 1980s onward.
Your body already makes thymosin β-4 in nearly every cell type — it's one of the most abundant intracellular peptides. This is a synthetic fragment of that sequence, laboratory-manufactured rather than extracted.
Sold in almost every recovery-peptide 'stack' online, usually paired with BPC-157 as the 'Wolverine' blend. The research on the parent thymosin β-4 protein is real and long-running. The specific TB-500 fragment protocol commonly discussed is much less validated.
Straight talk
Straight talk: thymosin β-4 has legitimate published biology — actin sequestration, cell migration, and preclinical work in rodent models. Human clinical evidence for the injectable TB-500 fragment as commonly sold is thin. Anyone promising specific outcomes in humans is running well ahead of the trial data.
What the research studies
The literature, not a summary of it.
The parent thymosin β-4 literature centers on Allan Goldstein's group at George Washington University and the RegeneRx clinical program. Journals: FASEB J, Ann N Y Acad Sci, Expert Opin Biol Ther. Read the research yourself:
Recommended vendor · Amino Club
≥ 99% by HPLC on the current lot — ILS Laboratories (ISO/IEC 17025).
$25.99 during Fall Sale (was $39.99)
35% off applied automatically at checkout when you land through this link.