TB-500
PreclinicalSynthetic Thymosin Beta-4 studied for repair & cell migration
Also known as: Thymosin Beta-4, Tβ4, TB4
TB-500 is a synthetic version of Thymosin Beta-4 (or its active fragment), a naturally occurring peptide studied for its role in actin regulation, cell migration, and tissue repair.
Molecular & research data
- Sequence
- Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES (Tβ4); active region LKKTETQ
- CAS number
- 77591-33-4
- Molecular formula
- C212H350N56O78S (Tβ4)
- Molecular weight
- ≈4963 g/mol (full Thymosin Beta-4)
- Half-life
- Estimated a few hours; the short active fragment is cleared faster
- Primary targets
- G-actin, Cell migration machinery
- Routes (research)
- Subcutaneous, Intramuscular
- Storage
- Lyophilised: −20 °C. Reconstituted: 2–8 °C, use within weeks.
Overview
TB-500 is the common research-market name for Thymosin Beta-4 (Tβ4) or its principal active fragment. Tβ4 is a naturally occurring 43-amino-acid peptide present in nearly all human cells and especially abundant at sites of injury. It plays a fundamental role in regulating the cell’s internal scaffolding.
The “TB-500” label is used loosely; products may contain the full peptide or a shorter synthetic fragment built around the LKKTETQ actin-binding region that carries much of the activity.
Mechanism of action
The defining mechanism of Thymosin Beta-4 is actin sequestration. It binds monomeric G-actin, acting as the main intracellular buffer of actin available for filament assembly. By regulating this pool, Tβ4 influences:
- Cell migration — essential for the movement of repair cells into damaged tissue
- Angiogenesis — supporting new blood vessel formation
- Reduced inflammation and scarring in several injury models
Because this actin-based mechanism differs entirely from the angiogenic/growth-factor route attributed to BPC-157, the two are frequently studied together as a complementary pair rather than as alternatives.
Common research uses
Preclinical investigation has focused on:
- Soft-tissue, muscle, and tendon repair
- Cardiac tissue protection and repair after injury
- Corneal and dermal wound healing
- Reduced fibrosis (scar tissue) in healing models
As with most peptides in this category, robust human clinical data are limited, and TB-500 should be regarded as a research compound.
Compare TB-500
TB-500 FAQ
What is the difference between TB-500 and Thymosin Beta-4?+
Thymosin Beta-4 (Tβ4) is the full 43-amino-acid natural peptide. "TB-500" is the research-market name for a synthetic version — sometimes the full peptide, sometimes its key active fragment (the LKKTETQ region) responsible for actin binding.
How is TB-500 thought to work?+
Its central mechanism is sequestering G-actin, which regulates the cytoskeleton and enables the cell migration involved in wound healing and tissue regeneration.
Is TB-500 approved for humans?+
No. It is not an approved human therapeutic, and it is prohibited in sport by the World Anti-Doping Agency. Most evidence is preclinical.
References
Related peptides
BPC-157
PreclinicalPentadecapeptide studied for tissue repair
BPC-157 is a synthetic 15-amino-acid peptide derived from a protein found in gastric juice, studied extensively in animal models for accelerated healing of tendon, ligament, muscle, and gut tissue.
GHK-Cu
Extensively studiedCopper-binding peptide for skin & repair
GHK-Cu is a naturally occurring copper-binding tripeptide extensively studied and widely used in skincare for collagen stimulation, wound healing, and tissue remodelling.
Last reviewed: 2026-06-26. Information is provided for research and educational reference only — see our disclaimer.