Factual overview of TB-500's regulatory position, anti-doping status, and what published research does and doesn't establish.
TB-500 is a synthetic fragment related to thymosin beta-4, a naturally occurring peptide. It is not approved by the FDA for any human use, and is not lawfully marketed for human consumption in the United States. It is sold under research-use-only labeling.
TB-500 is explicitly prohibited by the World Anti-Doping Agency at all times, listed among prohibited peptide hormones and growth factors. It has been the subject of multiple anti-doping cases in both human and equine sport.
Thymosin beta-4 itself has been studied for wound healing and cardiac repair, including some early-stage human trials for specific clinical indications such as corneal and dermal wound healing. Importantly, that research concerns pharmaceutical-grade thymosin beta-4 under clinical supervision — not the TB-500 fragment sold online, and not the uses commonly discussed in fitness contexts. Evidence for athletic injury recovery in humans is not established.
As with other gray-market peptides, purity, concentration and sterility are not guaranteed by any regulatory body. Long-term human safety data does not exist.
The coach's manual: progressive tendon loading, the pain rules that keep you training, a complete shoulder framework, sleep and nutrition for tissue repair. No compounds, no shortcuts — the levers that actually have evidence behind them.
Get REBUILD — $18Loading, volume management, sleep and nutrition are the levers a coach can actually work with — and they're the ones with evidence behind them.
One email a week: what actually works in training and nutrition, minus the hype. No spam, unsubscribe anytime.