← Back to all 50 compounds
#19Healing, Repair & Immune

TB-500

identity-ambiguous thymosin-beta-4-related research product

Evidence: anecdotalReviewed 2026-08-09
July 2026 PCAC recommendation

Recommended for possible 503A list inclusion

TB-500-related bulk drug substances for wound healing

Nonbinding advisory recommendation; not FDA drug approval and not a final addition to the 503A Bulks List as of 2026-08-09.

Investigated uses

  • Wound healing and tissue repair in preclinical/FDA review contexts.

Mechanism and hypotheses

  • The exact chemical identity of catalog “TB-500” is unresolved; FDA materials evaluated an LKKTETQ thymosin-beta-4 fragment, while vendors may use TB4 terminology.
  • Hypothesized: Wound-healing and recovery claims are preclinical and cannot be generalized across identity-ambiguous products.

Human evidence

  • FDA found no human administration studies of the evaluated TB-500 fragment for disease or wound healing. Limitations: Catalog identity is ambiguous, and full thymosin-beta-4 literature cannot be assumed to apply.

Safety highlights

  • No controlled human adverse-event incidence exists for the FDA-evaluated TB-500 fragment.
  • Identity ambiguity, immunogenicity, impurities and uncharacterized effects on angiogenesis/tissue remodeling are major uncertainties.

Regulatory context

No FDA-approved TB-500 drug was identified. In July 2026, PCAC recommended TB-500-related bulk drug substances for possible inclusion on the 503A Bulks List for wound healing. The recommendation is nonbinding and was not a final FDA listing as of August 9, 2026.

Sources used for this entry