Tissue Repair/ImmuneWADA Prohibited
TB-500
Synonyms: Thymosin Beta-4, Synthetic Tbeta4
Sequence: Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser
Critical Safety & Regulatory Notice
TB-500 is classified as a regulated, unapproved, or research-only substance. Doping/Regulatory Status: Not FDA approved. Strictly prohibited by WADA in- and out-of-competition.. Clinical safety profiles for human use are deficient or not approved.
History & Discovery Timeline
TB-500 was isolated originally in the 1970s (specifically 1977) from the thymus gland by Dr. Allan Goldstein. It was developed to study the role of thymic hormones in immune regulation and cellular wound healing.
What it is: TB-500 is a synthetic peptide containing the active 43-amino-acid sequence of Thymosin Beta-4. It is classified as an actin-sequestering peptide designed to accelerate tissue regeneration.
Proposed Mechanisms & Research Findings: It binds to G-actin, promoting cell migration, angiogenesis, and extracellular matrix reconstruction. It has a low molecular weight, allowing it to travel long distances through tissues to reach injured sites.
Regulatory & Safety Status: It is not FDA approved for human use. It is approved for veterinary use in racing horses. Sourcing gray-market formulations carries significant risks of impurities and non-sterility.
Athletic & Anti-Doping Status: TB-500 is strictly prohibited by WADA under Section S2 as a peptide hormone. Use results in immediate suspension and doping violations.
Understanding TB-500 Key Facts
Primary Target System:CNS, IMMUNE, NEUROENDOCRINE
Residue Count / Length:44 Amino Acids
Primary Action & Category:Actin Sequestration Peptide (Tissue Repair/Immune)
Primary Receptors:G-Actin monomer binding sites, Thymic Peptide receptors, Pituitary Secretagogues Site
Figure 1: Detailed molecular mechanism pathways of TB-500 (click to enlarge).