Low StockA 43-amino-acid peptide studied for its role in cell migration and tissue organization during remodeling.
TB-500 sequesters G-actin — maintaining the reserve pool that cells draw on during structural change. In preclinical wound models, administration has been associated with organized matrix deposition over scar formation.
The most advanced clinical development: Phase 2/3 trials of a derivative (RGN-259) for corneal epithelial healing.
Made in USA•Purity: 99% HPLC
Extensive preclinical tissue repair data; Phase 2/3 corneal healing trials represent the most advanced clinical development
This content summarizes published research for educational purposes. It is not medical advice.
Research summary based on 7 peer-reviewed sources•Last updated: February 10, 2026•View references ↓
TB-500 is found wherever tissue is healing — blood platelets, wound fluid, regenerating muscle. It controls how cells move into damaged areas and whether new tissue forms organized architecture or chaotic scar.1
The mechanism is actin sequestration. Actin is the structural protein that gives cells shape and lets them migrate. TB-500 maintains a reserve pool of actin building blocks, releasing them for rapid cytoskeletal remodeling when repair demands it. This positions the peptide as an orchestrator of the cellular response to injury.1
Research interest spans multiple repair contexts:
Phase 2 Dry Eye (2015): In 72 patients, 0.1% Thymosin β4 showed significant symptom and sign improvements versus vehicle.7
Venous Ulcer Trial (2007): In 72 patients across 10 European sites, 0.03% Thymosin β4 gel produced ~25% complete wound closure at 3 months.8
Phase 1 Safety: 80 healthy volunteers tolerated doses up to 1,260 mg IV daily × 14 days with no dose-limiting toxicity or serious adverse events.4
The cornea is avascular and immunologically privileged — conventional inflammatory healing is limited there. This highlights TB-500's direct cellular migration and organization effects.
This ophthalmic application represents the most advanced clinical development of a Thymosin Beta-4 derivative to date.
TB-500 has robust preclinical characterization. Human data are largely confined to topical ophthalmic applications.
The corneal trials provide primary human evidence, but involve topical delivery to specialized tissue. Translation of systemic effects to human physiology requires further clinical investigation.
For laboratory research use only.
| Amino Acid Sequence | Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser |
|---|---|
| Single-Letter Code | SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES |
| Molecular Formula | C212H350N56O78S |
| Molecular Weight | 4963.44 g/mol |
| Amino Acid Count | 43 |
| CAS Number | 77591-33-4 |
| PubChem CID | 16132341 |
| Origin | Synthetic peptide corresponding to the active region of Thymosin Beta-4 (TB4), a naturally occurring 43-amino acid protein involved in actin regulation |
| Synonyms | Thymosin Beta-4, TB4, Tβ4 |
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Do not freeze. Use within 30 days of mixing.