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Recovery & Tissue Research

TB-500

Also referenced as: Thymosin beta-4 fragment, TB4 fragment, Tβ4 (1-4) related

A synthetic fragment related to thymosin beta-4, studied in animal wound-healing models.

Quick answers

What is TB-500?
TB-500 is a synthetic fragment linked to thymosin beta-4, a natural protein involved in cell movement and wound repair. It is studied for recovery and tissue healing.
What are the side effects of TB-500?
There are no reliable human trials of TB-500 itself, so its side-effect profile is unknown. Research on full thymosin beta-4 does not automatically apply to the fragment.
Is TB-500 legal or FDA approved?
No. TB-500 is not FDA approved for human use and is banned in sport by WADA.
Does TB-500 work?
Evidence comes mostly from animal and lab studies of thymosin beta-4. Human benefit from TB-500 has not been shown in controlled trials.

Educational summary, not medical advice. Sources are listed below.

Evidence grade
DPreclinical Research

Preclinical Research

Regulatory status
Research Use Only

Not approved for any indication and prohibited in sport under WADA rules. Note that full-length thymosin beta-4 and the marketed TB-500 fragment are not interchangeable.

Human data
Limited

No registered clinical trials identified

Last reviewed
September 1, 2026

Overview

Thymosin beta-4 is a naturally occurring actin-binding protein involved in cell migration and wound repair. TB-500 refers to a synthetic fragment of that sequence sold for research use.

Published human work involves the full protein in ophthalmic and cardiac indications, not the fragment in musculoskeletal recovery, which is how it is usually discussed.

Why It's Being Studied

  • Cell migration and wound repair mechanisms.
  • Corneal healing and dry eye, where full-length thymosin beta-4 reached early clinical study.
  • Cardiac repair after ischaemic injury in animal models.

Mechanism of Action

In plain language

It binds to part of the cell's internal scaffolding, which helps cells move into a wound and rebuild tissue.

Technical detail

Thymosin beta-4 sequesters G-actin and promotes actin polymerisation dynamics, supporting cell motility. Downstream reports include upregulated laminin-5, reduced inflammatory cytokine expression, and angiogenic effects. The relative activity of truncated fragments remains poorly characterised.

Interactive diagram

The stages of tissue repair

Tap each stage to see what happens.

Injury: Tissue damage triggers bleeding and clotting.

Background: Recovery & Tissue Research

Tissue-repair peptide research looks at the stages of healing — inflammation, new blood-vessel growth, cell migration and remodelling — and asks whether a signal can speed or improve any of them.

Most of this literature is animal and cell work. Rodent tendon, gut and wound models heal quickly and differently from human tissue, so strong-looking preclinical results often do not translate.

Research Areas & Routes Studied

Areas studied
  • Wound healing
  • Corneal repair
  • Cardiac repair
  • Inflammation
Routes used in research
  • Subcutaneous injection (animal research)
  • Topical (ophthalmic studies of the full protein)

Evidence Summary

Animal and cell research on thymosin beta-4, plus limited early human trials of the full protein in specific indications. TB-500 as sold is a fragment, and human evidence for it is absent.

Evidence pyramid

Higher tiers carry more weight. Filled tiers have evidence for TB-500; tap to read it.

Human clinical trials
  • Early trials of full-length thymosin beta-4 in dry eye and corneal wounds have been reported. These do not establish efficacy for the marketed fragment or for injury recovery.
Source breakdown

2 cited sources.

  • Narrative review1
  • Clinical trial1

Human clinical evidence

  • Early trials of full-length thymosin beta-4 in dry eye and corneal wounds have been reported. These do not establish efficacy for the marketed fragment or for injury recovery.

Animal studies

  • Wound, cardiac and neural injury models report improved repair markers.

Anecdotal / community information

  • Widely reported alongside BPC-157 in injury-recovery discussion. No established human dosing protocol exists.

Reported Adverse Events in Research

  • No systematic human safety data for the fragment.
  • Angiogenic activity raises the same theoretical oncological questions as other pro-repair peptides.

Limitations of Current Evidence

  • The marketed fragment is not the molecule studied in most published research.
  • No controlled human musculoskeletal outcomes exist.

How to Read This Research

Questions to ask
  • Was the study in humans, animals or cells?
  • Was healing measured by function (strength, pain, movement) or only by tissue appearance?
  • Was there a control group receiving the same care without the compound?
Reading tips
  • Growth-promoting signals raise theoretical questions about unwanted growth; absence of reported harm in short animal studies is not proof of safety.
  • Rodent injury models are often surgically created and heal in days — be cautious extrapolating time frames.
Angiogenesis
Formation of new blood vessels.
Fibroblast
A cell that produces collagen and connective tissue.
Preclinical
Research done before human testing — in animals or cells.

Compare With Other Compounds

Compare side by side
TB-500BPC-157
Evidence gradeD — Preclinical ResearchD — Preclinical Research
Regulatory statusResearch Use OnlyNot FDA Approved
Human dataLimitedLimited
Clinical trialsNone identifiedNone identified
Research routesSubcutaneous injection (animal research), Topical (ophthalmic studies of the full protein)Subcutaneous injection (animal research), Intraperitoneal (animal research), Oral (animal research)
Cited sources23
Also in Recovery & Tissue Research
BPC-157 · DCartalax · E

Frequently Asked Questions

Documented Research Protocols

  • TB-500 — research context, not a human protocol

    Explain what published thymosin beta-4 research covers and why no human protocol for the marketed fragment can be summarised.

    View documented protocol

Why It Is Used

  • Recovery

    Soft-Tissue Injury and Recovery

    BPC-157 is the single most searched research peptide. The gap between how confidently it is discussed and what has been published in humans is the story here.

    Read the case study

Research References

This page is an educational research summary. It is not medical advice, does not recommend human use, and does not provide individualised dosing. Many compounds discussed here are research use only and are not approved medicines.