TB-500
Thymosin beta-4 fragment
REC PPT-TB-500 // REV 2026-10-04 // assessment changes are logged, never silent
Synthetic fragment of thymosin beta-4. Animal repair data; human data scarce.
What it is
A synthetic peptide corresponding to an active region of thymosin beta-4, a naturally occurring protein involved in cell migration and actin regulation.
What it does
Implicated in cell migration, actin binding and tissue remodelling in laboratory models — the mechanistic rationale for claims around soft-tissue recovery.
Does it work?
Preclinical work is reasonably developed. Controlled human trials for the recovery uses it is marketed for are lacking. It is prohibited in competitive sport under WADA rules.
Claims vs data
Each marketing claim, tagged by what the evidence actually supports.
| Improves soft-tissue recovery | animal data only |
| Banned in competitive sport | supported |
Reference figures
Quoted from published reference material. These are not Peptuity recommendations.
molecular data — PubChem CID 45382195 · values are for thymosin beta-4 (parent molecule)
The evidence, counted
Live counts from Europe PMC and ClinicalTrials.gov.
110 publications indexed, but only 2 randomised controlled trials and 1 registered interventional studies. Human evidence exists but is thin.
SRC // EUROPE PMC + CTGOV // "TB-500" // FETCHED 2026-10-04 // 110 RECORDS
Most-cited literature
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[01]
Pharmacological evidence for a metabotropic glutamate receptor heterodimer in neuronal cells
Moreno Delgado D, Møller TC, Ster J, Giraldo J, Maurel D, Rovira X, Sc · Elife 2017 · 84 citations · DOI 10.7554/elife.25233
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[02]
MAZ-binding G4-decoy with locked nucleic acid and twisted intercalating nucleic acid modifications suppresses KRAS in pancreatic cancer cells and delays tumor growth in m
Cogoi S, Zorzet S, Rapozzi V, Géci I, Pedersen EB, Xodo LE. · Nucleic Acids Res 2013 · 81 citations · DOI 10.1093/nar/gkt127
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[03]
Identification of the Clostridium perfringens genes involved in the adaptive response to oxidative stress
Briolat V, Reysset G. · J Bacteriol 2002 · 80 citations · DOI 10.1128/jb.184.9.2333-2343.2002
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[04]
Functional characterization of iPSC-derived arterial- and venous-like endothelial cells
Rosa S, Praça C, Pitrez PR, Gouveia PJ, Aranguren XL, Ricotti L, Ferre · Sci Rep 2019 · 77 citations · DOI 10.1038/s41598-019-40417-9
Regulatory status
Formal, dated regulatory actions.
WADA — Prohibited List 2026
Prohibited in sport — WADA S2 (peptide hormones, growth factors and related substances)
US FDA — 503A compounding 2026-07
Advisory committee (PCAC) voted 8–6 in July 2026 to recommend inclusion on the 503A compounding list — non-binding, and against the written recommendation of FDA staff. Rulemaking pending; this is not an approval, and the earliest legally compounded product is estimated at late 2027.
Common questions
Is TB-500 the same as thymosin beta-4?
Not exactly. TB-500 is a synthetic fragment corresponding to the active region of thymosin beta-4, not the full protein.
Is there human evidence for recovery use?
Very little. Preclinical work is reasonably developed, but controlled human trials for the recovery uses it is marketed for are lacking.
Can athletes use TB-500?
Not in tested sport. It is explicitly prohibited under WADA rules, and positives have led to sanctions.
Did the FDA just approve TB-500?
No. In July 2026 an FDA advisory committee voted 8–6 to recommend adding it to the 503A compounding list — a non-binding recommendation made against FDA staff advice. Approval status is unchanged, and rulemaking could run into late 2027.