TB-500
Thymosin Beta-4 fragment
Synthetic fragment of Thymosin Beta-4. Promotes systemic tissue repair through actin regulation and stem cell activation. Often stacked with BPC-157.
Mechanism of action
Promotes actin polymerization critical for cell migration and tissue repair. Activates stem cell recruitment to injury sites, reduces inflammatory cytokines TNF-α and IL-6, enhances angiogenesis and neurogenesis systemically.
Effects in the body
TB-500 is systemic in scope — it works throughout the entire body. The actin regulation mechanism means it affects virtually every cell that needs to migrate during healing. Works synergistically with BPC-157 for comprehensive repair protocols.
Pros & cons (from the literature)
- Systemic reach — whole-body repair signaling
- Reduces inflammation AND scar tissue formation
- Supports muscle, tendon, ligament, and cardiac tissue repair
- Strong preclinical data across multiple tissue types
- Synergistic with BPC-157
- Accelerated dormant tumor growth found in some animal models — significant concern
- No completed human clinical trials
- Immunogenicity risks not fully characterized
- May disrupt immune response in certain scenarios
- Optimal human dosing not established
Protocol summary (from published research)
Dosing ranges reproduced from published research literature. Not a prescription, not medical advice.
FDA & regulatory status
Evidence base
Strong preclinical data. Full TB4 molecule in human cardiac and dry eye clinical trials. No completed human trials specifically for TB-500 fragment.
Primary research sources
Peer-reviewed literature referenced throughout this profile is drawn from PubMed, Cell Metabolism, and clinical trial registries cited in the evidence base above.
Expert perspective — Dr. Alex Tatem, Urologist
Dr. Alex Tatem is a board-certified Urologist and Men's Health Specialist who has studied peptides for 12 years. Videos featured for educational purposes. ThePeptide.expert is an independent platform.
Dr. Tatem covers TB-500 as part of his comprehensive breakdown of the recovery peptide stack and the FDA regulatory landscape in 2026.
Common questions about TB-500
What is TB-500?
TB-500 is a synthetic fragment of Thymosin Beta-4, a naturally occurring protein involved in tissue repair and cell migration. It is studied for systemic tissue repair, particularly for injuries where BPC-157's more localized effects are insufficient. The two are frequently researched together as the Wolverine Stack.
Is TB-500 the same as Thymosin Beta-4?
No — TB-500 is a specific fragment (amino acids 17-23) of Thymosin Beta-4, not the complete protein. This fragment is believed to be responsible for much of Thymosin Beta-4's tissue repair activity and is more practical to synthesize. The terms are sometimes used interchangeably in community discussions but they are chemically distinct.
What happened to TB-500 at the July 2026 PCAC hearing?
The FDA's PCAC voted 8-6-1 to recommend TB-500 for the 503A Bulks List on July 23, 2026 — the same vote margin as BPC-157 and KPV. This recommendation is advisory only. Formal rulemaking is still required. See the PCAC tracker for current status.
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