TB 500 is a synthetically made version of TB4 that facilitates healing and recovery by helping build new blood vessels, muscle tissue fibers, blood cells, and facilitating cell migration. It acts on the muscular system and has anabolic properties. TB 500 is used primarily for race animals (horses and dogs).
TB 500 is a peptide hormone that represent an emerging class of potential doping agents.
TB500 is a synthetic version of an active region of thymosin β4. TB500 is claimed to promote endothelial cell differentiation, angiogenesis in dermal tissues, keratinocyte migration, collagen deposition and decrease inflammation.
Blood vessels are an essential precondition for any biochemical activity, including cell proliferation, tissue repair and remodeling, and other activities. In animal and in vitro models, it has been purported that TB-500 may promote the migration of endothelial cells, which line blood vessels. Through its potential to stimulate migration, TB-500 may have the prospect of stimulating the formation of blood vessels in animal models, even in tissues such as cartilage. Findings imply that by promoting cell development, TB-500 may assist in tissue repair and help guarantee that the repair is more comprehensive. It was speculated via research conducted on mice models of heart attack that TB-500 might stimulate the creation of capillary tubes, promoting heart muscle regeneration and preventing heart cell death after damage. In a nutshell, TB-500 may both discourage cell harm and promote cell healing once it has already occurred.
In 2011, a veterinary preparation called TB-500 containing the synthetic version of this naturally occurring peptide segment was marketed for equine or greyhound use. Although the preparation is declared '100% drug-free' and 'does not swab', TB-500 (N-acetylated LKKTETQ) is prohibited in horse racing as implicit in Clause 10 of Article 6 of the International Agreement on Breeding, Racing and Wagering (published by the International Federation of Horseracing Authorities)[1].
[1] Emmie N M Ho. “Doping control analysis of TB-500, a synthetic version of an active region of thymosin β?, in equine urine and plasma by liquid chromatography-mass spectrometry.” Journal of Chromatography A 1265 (2012): 57–69.