TB-500
Thymosin Beta-4 Fragment
TB-500 is a synthetic fragment of thymosin beta-4, studied in preclinical and veterinary settings for tissue repair. It is not FDA-approved for human use and is WADA-prohibited.
Overview
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.
Research context
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.
Safety and regulatory framing
FDA compounding safety concern; WADA prohibited; no human approval
TB-500 is not FDA-approved for any human use. The FDA has included thymosin beta-4 fragment among substances with safety concerns for compounding, citing issues related to immunogenicity, impurities, and insufficient human safety data. TB-500 is also prohibited by WADA as a peptide hormone and growth factor.
Products sold as 'TB-500' through research chemical suppliers are unregulated, not manufactured to pharmaceutical standards, and explicitly labeled for research use only. Quality, purity, and potency are not guaranteed. Regulations vary by jurisdiction. Readers should consult a licensed healthcare provider before considering any unapproved substance.
References
- Goldstein AL, et al. "Thymosin β4: A Multi-Functional Regenerative Peptide." Expert Opin Biol Ther (2012) ↗Expert Opinion on Biological Therapy
- Sosne G, et al. "Thymosin Beta-4 and Corneal Wound Healing." Ann NY Acad Sci (2010) ↗Annals of the New York Academy of Sciences
- FDA Bulk Drug Substance Compounding Safety Concerns ↗FDA.gov
- WADA Prohibited List — Peptide Hormones, Growth Factors ↗WADA
Research information only
Peptide Daily is an informational resource only. Peptide research chemicals are not approved for human use by the FDA unless otherwise noted. Nothing on this site constitutes medical advice. Consult a qualified healthcare provider before using any peptide or research chemical.
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