Synthetic fragment of Thymosin Beta-4 researched for tissue repair, inflammation reduction, wound healing, and cardiac tissue recovery.
Last Updated: May 2026
TB-500 is a synthetic fragment of Thymosin Beta-4 (Tβ4) — specifically the active region containing the actin-binding domain — researched for tissue repair, wound healing, anti-inflammatory effects, and cardiac tissue recovery. It is one of the most-researched tissue-repair peptides alongside BPC-157. Important regulatory update: TB-500 was removed from the FDA's Category 2 bulk substances list on April 22, 2026 and is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review on July 23, 2026, with the FDA specifically evaluating its use for wound healing.
TB-500 is a synthetic fragment of Thymosin Beta-4 (specifically the 17-amino-acid actin-binding region of the 43-amino-acid full Tβ4 peptide), proposed to act through actin sequestration and release mechanisms that modulate cell migration, angiogenesis, and tissue regeneration. Thymosin Beta-4 itself is a major intracellular protein involved in cytoskeletal regulation; the synthetic fragment retains many of the regenerative effects of full Tβ4 with simplified pharmacokinetics. Evidence level: Preclinical extensive (wound healing, cardiac repair, neural regeneration); limited human clinical research; FDA PCAC review July 2026 for wound healing.
Preclinical studies have demonstrated effects on wound healing, cardiac tissue recovery post-MI, corneal repair, neural regeneration, and broad tissue-repair mechanisms across multiple animal models. Full-length Thymosin Beta-4 (RGN-352) has been studied in Phase 2 trials for diabetic foot ulcers and other indications by RegeneRx; TB-500 specifically (the fragment) is more commonly used in research and community contexts. The July 2026 PCAC review will evaluate TB-500 specifically for wound healing. Evidence level: Preclinical extensive across multiple tissue contexts; full Tβ4 has Phase 2 human data; TB-500 fragment human data limited; FDA PCAC review pending.
TB-500 (the fragment) and full-length Thymosin Beta-4 are mechanistically related but pharmacokinetically different — the fragment is more commonly used in research-grade markets, full Tβ4 has more direct clinical development history. BPC-157 and TB-500 are the two flagship tissue-repair peptides; they are often paired in community protocols though no formal head-to-head comparison data exists.
| Compound | Structure | Mechanism | FDA pathway |
|---|---|---|---|
| TB-500 | 17-AA Thymosin Beta-4 fragment | Actin binding, cell migration | PCAC July 2026 (wound healing) |
| Full Thymosin Beta-4 (RGN-352) | 43-AA full peptide | Same mechanism family | Phase 2 (diabetic foot ulcer) |
| BPC-157 | 15-AA pentadecapeptide | Multi-pathway tissue protection | PCAC July 2026 (UC) |
Side effects in available preclinical safety data and community-reported research use are generally mild — injection-site reactions are the most common report. Theoretical concerns about angiogenesis effects (relevant for cancer biology) have been raised — similar to BPC-157 — given Thymosin Beta-4's role in vascular development. Clinical substantiation of these concerns is absent in available data. Long-term safety in humans at sustained research-use dosing is not characterized at Western RCT standards. Evidence level: Preclinical safety; human long-term unestablished; theoretical angiogenesis concerns unaddressed.
TB-500 is not approved for any medical indication anywhere in the world as of May 2026. On April 22, 2026, TB-500 was removed from the FDA's Category 2 bulk substances list. The Pharmacy Compounding Advisory Committee will review TB-500 on July 23, 2026 specifically for the proposed use in wound healing. Removal from Category 2 does not authorize compounding pending PCAC determination. Current status in FDA peptide regulation 2025–2026 timeline.
TB-500 is widely sold in research-grade markets with substantial quality variance, and the distinction between TB-500 (the 17-AA fragment) and full Thymosin Beta-4 (the 43-AA full peptide) requires mass spectrometry verification — some vendors sell one mislabeled as the other. Independent HPLC purity testing is the standard quality signal. As with BPC-157, the acetate versus free base form should be clearly identified. Guidance in how-to-test-peptides hub.
Peptigrity purchases TB-500 vials anonymously at standard customer pricing, sends them to ISO-accredited third-party labs for HPLC and mass spectrometry analysis, and publishes the unedited certificate of analysis. Methodology in how we calculate trust scores.
TB-500 is researched for tissue repair, wound healing, cardiac tissue recovery, and broad regenerative effects through actin-binding mechanisms related to cell migration and tissue regeneration. Preclinical evidence is extensive; the July 2026 PCAC review will evaluate the proposed wound healing indication.
TB-500 is legal to purchase as a research chemical for laboratory use in most jurisdictions, but it is not approved for human consumption. The April 22, 2026 Category 2 removal and July 23, 2026 PCAC review represent an advanced regulatory pathway. Country breakdown in peptide legal status guide.
The Pharmacy Compounding Advisory Committee will review TB-500 on July 23, 2026, evaluating its proposed use for wound healing. The PCAC will make a recommendation to the FDA on 503A bulks list inclusion. Track developments in FDA peptide regulation 2025–2026 timeline.
No. TB-500 is the 17-amino-acid actin-binding fragment of the 43-amino-acid full Thymosin Beta-4 peptide. Both are mechanistically related; the fragment is more common in research-grade markets, full Tβ4 (RGN-352) has more direct pharmaceutical clinical development history.
The theoretical angiogenesis-related concern (similar to BPC-157) has been raised in mechanism discussions but has not been clinically substantiated. Long-term human surveillance has not been conducted at scale. Anyone with active cancer or cancer history should consult a licensed physician before considering TB-500.
Independent third-party HPLC certificate of analysis from a lab the vendor does not own or pay, with mass spectrometry identity confirmation distinguishing TB-500 (17-AA fragment) from full Thymosin Beta-4 (43-AA) and from related Thymosin Beta-4 fragments. Verify whether acetate or free base form. COA interpretation in red flags in peptide certificates of analysis.
No. TB-500 is not approved for human consumption and Peptigrity is an independent review platform, not a medical authority. Research-use dosing in community protocols varies widely. Anyone considering use should consult a licensed physician.
Yes. TB-500 (and Thymosin Beta-4 derivatives) are on the WADA Prohibited List (Section S2 — Peptide Hormones). Detection methods for Thymosin Beta-4 fragments have been developed and improved. For drug-testing context, see do peptides show up on drug tests.
This section is for educational and informational purposes only and does not constitute medical advice. TB-500 is not approved by the FDA or any major Western regulator for human use, though it was removed from Category 2 of the FDA 503A bulk substances list in April 2026 and is scheduled for PCAC review on July 23, 2026 for the proposed use in wound healing. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.
Real protocols and questions from members — independent of vendors, never sponsored.
Sign in to ask a question.
Every submitted test helps the community verify purity across brands. Free, fast, independent.