TB-500

Safety Profile

How It Works

TB-500 works by controlling actin, a protein inside every cell that acts like scaffolding. By binding to actin monomers, TB-500 keeps cells flexible and mobile, allowing repair cells (fibroblasts, endothelial cells) to migrate rapidly to injury sites. It also reduces inflammation by blocking NF-κB signaling, promotes blood vessel growth (angiogenesis), prevents scar tissue formation, and protects cells from dying. Think of it as helping your body's repair crew get to the injury faster and work more efficiently.

Reported Dosing References

Sequential dose-escalation cohorts in adults with stable atherosclerotic CVD; specific dose levels, route, and frequency are protocol details and remain unpublished.

Studies

Zero completed peer-reviewed human RCTs, observational cohorts, or pharmacovigilance datasets of TB-500 are present in the ledger.

Legal Status

TB-500 referenced on FDA's 'Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks' page; not an FDA-approved drug. TB-500 is not a marketed approved therapeutic in the United States; FDA's compounding-risk framing flags peptide-impurity, API-characterization, and immunogenicity concerns relevant to the broader thymosin family. This is a regulatory caution signal, not an outright ban statement, and should be re-checked at the source URL. TB-500 referenced on FDA's 'Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks' page; not an FDA-approved drug. TB-500 is not a marketed approved therapeutic in the United States; FDA's compounding-risk framing flags peptide-impurity, API-characterization, and immunogenicity concerns relevant to the broader thymosin family. This is a regulatory caution signal, not an outright ban statement, and should be re-checked at the source URL. Not FDA-approved for any indication. Not DEA-scheduled. FDA placed TB-500/Thymosin Beta-4 Fragment in 503A Category 2 (substances that may present significant safety risks, do not compound) in late 2023. HHS announced in February 2026 intent to reclassify ~14 peptides to Category 1 including TB-500. HOWEVER: raw data sources conflict -- states reclassified to Cat 1; citing official FDA sources states remains Cat 2 with 'no reclassification confirmed as of 2026.' Regulatory status may be in flux; verify before relying on current compounding legality. NOTE: HHS Secretary Kennedy announced Feb 27, 2026 that this peptide is expected to be reclassified to Category 1 (pending formal FDA publication) (compoundable). Official FDA publication pending as of March 2026.