Peptide library · Recovery & repair
TB-500
Thymosin beta-4 fragment
Research stageNature2004 study: thymosin beta-4 improved heart cell survival and function after heart attack in mice
What it is
A synthetic fragment of thymosin beta-4, a repair peptide your own cells make. It helps cells move and build new blood vessels.
Why researchers are interested
- Thymosin beta-4 is involved in cell migration, blood vessel growth and tissue repair.
- Landmark 2004 Nature study in mice after heart attack.
- Eye drop trial of the full molecule (72 people) improved several dry eye measures.
Good to know
- Not FDA approved. An FDA advisory panel voted 8 to 6 in July 2026 to allow compounding.
- No human trials of injected TB-500 yet. Prohibited in sport (WADA).
Evidence level: 2 of 5
Sources
Bock-Marquette et al., Nature 2004; Sosne et al., Clin Ophthalmol 2015; AJMC, Jul 2026
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Educational content only. Not medical advice. Last reviewed 2026-10-17.