# TB-500

> Evidence tier C — Animal data · Repair · reviewed 2026-11-08
> Source page: https://peptidemeta.com/p/tb-500/

Also known as: TB500, Thymosin beta-4 fragment, Ac-LKKTETQ

## Quick answers

**What is TB-500?**

A synthetic fragment of thymosin beta-4 that promotes tissue repair, cell migration, and blood vessel growth. TB-500 is a marketing name for a synthetic thymosin β4 fragment (commonly the actin-binding region around LKKTETQ, often N-acetylated); composition varies between products.

**How strong is the evidence for TB-500?**

Tier C (animal data) on the peptidemeta evidence scale. No human trials of TB-500 itself; supporting data come from animal studies and from research on full-length thymosin β4.

**Is TB-500 FDA-approved?**

No. TB-500 is not approved by the FDA for any use.

**Is TB-500 banned in sport?**

Yes. TB-500 is prohibited in sport by the World Anti-Doping Agency under S2 (peptide hormones, growth factors, related substances and mimetics).

**How does TB-500 work?**

TB-500 (thymosin beta-4 fragment) sequesters G-actin monomers and promotes actin polymerization, which drives cell migration and wound healing. It upregulates cell surface integrins and promotes angiogenesis, enabling new blood vessel formation at injury sites.

**What is known about the safety of TB-500?**

Limited human safety data. Animal studies show good tolerability.

## Key facts

- **Evidence tier:** C (Animal data)
- **FDA:** not approved
- **WADA:** prohibited (S2)
- **Peptide:** yes
- **Routes studied:** Subcutaneous, Intramuscular

## Overview

A synthetic fragment of thymosin beta-4 that promotes tissue repair, cell migration, and blood vessel growth. Valued in recovery protocols for soft-tissue injuries.

## Mechanism

TB-500 (thymosin beta-4 fragment) sequesters G-actin monomers and promotes actin polymerization, which drives cell migration and wound healing. It upregulates cell surface integrins and promotes angiogenesis, enabling new blood vessel formation at injury sites.

## Effects reported in research

_Reported outcomes, not promises; see the evidence tier._

- Enhanced wound healing and tissue repair
- Reduced scar tissue formation
- Improved flexibility and joint mobility
- Promoted new blood vessel growth

## Safety & unknowns

Limited human safety data. Animal studies show good tolerability. Potential concerns include theoretical tumor promotion due to angiogenic activity. Not FDA-approved. Banned by many sports organizations.

## Status sources

- [PubMed: TB-500 / thymosin β4 fragment](https://pubmed.ncbi.nlm.nih.gov/?term=TB-500+thymosin)
- [WADA 2026 Prohibited List](https://www.wada-ama.org/en/prohibited-list)

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Educational reference only — not medical advice. No dosing information is published. Tiers rate the strength of published evidence, not effectiveness or safety.