TB-500

TB-500 is a synthetic peptide fragment derived from thymosin beta-4 (Tβ4), a naturally occurring 43-amino-acid protein found in virtually all human and animal cells. Thymosin beta-4 plays a central role in actin regulation, which is fundamental to cell migration, proliferation, and differentiation — processes critical to wound healing and tissue repair. TB-500 typically refers to a specific active fragment of the thymosin beta-4 sequence.

TB-500 has been studied primarily in preclinical and veterinary settings, with particular interest in wound healing, tissue repair, and reduction of inflammation. It has not been approved by the FDA for any human use and is classified among the peptides with safety concerns for compounding purposes.

The parent molecule, thymosin beta-4, has a more extensive research literature than TB-500 specifically. Preclinical studies of thymosin beta-4 have investigated its effects in wound healing and dermal repair models, cardiac tissue repair following myocardial infarction, corneal wound healing, and inflammation modulation and anti-fibrotic effects.

Thymosin beta-4 has been evaluated in some human clinical settings, particularly in ophthalmology (corneal wound repair) under the investigational drug name RGN-259. However, TB-500 (the fragment) has not undergone the same level of clinical investigation. In veterinary medicine, TB-500 has been used in equine settings for injury recovery, though regulatory bodies in horse racing have restricted its use.