TB-500
Also searched as: Thymosin Beta-4 fragment · TB4 frag
TB-500 is a synthetic peptide corresponding to a short active region of Thymosin Beta-4, a protein present in most human cells and in wound fluid. It is not the whole protein: it is a fragment of seven amino acids, which is why the two names are not interchangeable despite often being used as if they were.
What the research has looked at
- Cell migration and actin regulation in laboratory studies
- Wound closure rates in animal models
- Cardiac tissue following induced injury in mice
- Corneal healing in animal studies
This is a description of what has been studied, not a claim about what it does. Evidence level: animal studies only.
Legal position in the UK
Not a licensed medicine in the UKNot licensed as a medicine in the UK. Prohibited in sport at all times under WADA class S2 (peptide hormones, growth factors and related substances).
Handling and storage
Lyophilised powder, reconstituted with bacteriostatic water. Larger vial sizes are common, which often means a larger water volume and therefore a higher click count on a dosing pen.
Vial sizes: Commonly 2mg, 5mg or 10mg per vial. Where a manufacturer supplies handling instructions, those take precedence over anything general.
Questions
- Is TB-500 the same as Thymosin Beta-4?
- No. Thymosin Beta-4 is a 43-amino-acid protein occurring naturally in the body. TB-500 is a synthetic seven-amino-acid fragment of it. They are frequently conflated online and in supplier listings, but they are different molecules.
- What is the state of the human evidence?
- Thin. The bulk of published work is preclinical, in cell cultures and animal models. Thymosin Beta-4 itself has been through some early human trials for specific indications; the TB-500 fragment has far less behind it.