TB-500 is a lab-made copy of the active part of Thymosin Beta-4, a natural protein with 43 amino acids. Scientists have tested Thymosin Beta-4 mostly in animals, for cell movement and wound healing. The only human trials used an eye drop.
Why scientists study it
- In lab and animal studies its active stretch, 17LKKTETQ23, held actin in reserve and made blood vessel, surface and progenitor cells move without making them multiply.
- Wound repair was tested in skin, cornea and heart models, with two well-known Nature papers and finished Phase II and Phase III eye trials of RGN-259, a drop made with whole Tβ4.
- In heart and tissue injury models it lowered inflammation by holding back NFkappaB, and it helped cells survive through integrin-linked kinase (ILK) and Akt.
Three studies to know
1999 · Journal of Investigative Dermatology
Malinda and colleagues gave Tβ4 to rats with full-thickness skin wounds, on the skin or into the abdomen. Regrowth of the skin surface was 42% higher at 4 days and 61% higher at 7 days than with saline. The wounds also shrank more, made more collagen and grew more blood vessels. Read the paper
2007 · Nature
Smart and colleagues found that the heart’s coronary vessels need Tβ4 to develop. It drew outgrowth from resting adult epicardial tissue, and the cells became endothelial cells, smooth muscle cells and fibroblasts. The paper set out its part in moving adult epicardial progenitor cells and growing new vessels. Read the paper
2022 · Int. J. Molecular Sciences
Sosne and colleagues reported SEER-1, a Phase III trial of the 0.1% RGN-259 (Tβ4) eye drop in neurotrophic keratopathy. It was randomized, placebo-controlled and double-masked. Eye discomfort, the feeling of something in the eye and Mackie disease stage all improved significantly, and no defects had come back at day 43. Read the paper
Safety and legal status
- Outside eye care, all the evidence comes from animals and cells. No randomized controlled trial in people has been finished for TB-500 or whole-body Tβ4 apart from the RGN-259 eye program, and long-term safety is not known.
- It is not approved by the FDA, the EMA or the MHRA. The World Anti-Doping Agency bans Thymosin Beta-4 and its derivatives, TB-500 included, at all times, in and out of competition. They come under its class S2 (peptide hormones, growth factors and related substances).
- For laboratory research and in vitro (lab dish) use only. It is not meant for human use.
Related compounds
- BPC-157: Lab-made chain of 15 amino acids, tested in animals for blood vessel growth and tissue repair.
- BPC-157 + TB-500: Two repair peptides, each tested alone in animals. No study has tested them together.
- GHK-Cu: Copper-bound chain of three amino acids, tested in cells and animals for skin and wound repair.