Also known as: TB500, 885340-08-9, UNII-QHK6Z47GTG, QHK6Z47GTG, (2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-4-methylpentanoyl]amino]-6-aminohexanoyl]amino]-6-aminohexanoyl]amino]-3-hydroxybutanoyl]amino]-4-carboxybutanoyl]amino]-3-hydroxybutanoyl]amino]-5-amino-5-oxopentanoic acid, TB 500, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-OH, L-Glutamine, N-acetyl-L-leucyl-L-lysyl-L-lysyl-L-threonyl-L-alpha-glutamyl-L-threonyl-
TB-500 (TB500, 885340-08-9, UNII-QHK6Z47GTG) is classified under repair & thymosin peptides, sold for research use only and not approved for human consumption.
Aggregated from the cited literature below. We summarize sources — we don't author claims.
TB-500 (also referred to as TB500; thymosin β4 fragment) is described in the provided literature as a peptide being used/marketed in contexts such as orthopaedics/sports medicine and as a doping-relevant compound. Narrative reviews report that evidence for clinical benefit in musculoskeletal outcomes is limited, with many findings largely based on preclinical work. Multiple studies focus on analytical detection of TB-500 (and its thymosin β4–derived segment) in equine and human doping-control settings.
Mechanism (as reported)
Mechanistic descriptions in the provided sources for TB-500 reference a thymosin β4 active segment (LKKTETQ, including an N-terminal acetylated form in TB-500 formulations) that is described as an actin-binding region involved in processes such as cell migration and wound healing; related work and reviews also associate TB-500 with angiogenesis and tissue-repair–related cellular behaviors (as claimed in those sources). (PMIDs: 23084823, 41490200)
Key findings (each cites a source)
A narrative review of injectable peptide therapy in orthopaedics reported that TB-4 and its derivative TB-500 promoted angiogenesis and tissue repair in preclinical models, while human orthopaedic data were reported to be lacking. (PMID: 41476424) [PMID 41476424]
An orthopaedics-focused review described wound-healing peptides including TB-500 as promoting angiogenesis, integrin-mediated extracellular matrix remodeling, and fibroblast activation, while also noting a current lack of clinical trials. (PMIDs: 41490200) [PMID 41490200]
A narrative review on peptide therapies for musculoskeletal injuries and athletic performance described TB-500 as an unapproved compound marketed direct to patients and stated that rigorous human safety data are scarce, with potential for serious harm; it also characterized many unapproved peptides as showing favorable tissue repair/metabolic outcomes in animal models. (PMIDs: 41966639) [PMID 41966639]
A study on doping control analysis in equine urine and plasma described TB-500 as a veterinary preparation containing a synthetic version of the naturally occurring thymosin β4 segment LKKTETQ, and described a detection method for N-acetylated LKKTETQ (and metabolites) in post-administration equine samples. (PMIDs: 23084823, 42021992) [PMID 23084823, 42021992]
A synthesis/analytical study reported detection and identification of the N-terminal acetylated thymosin beta 4 17–23 fragment (Ac-LKKTETQ) in TB-500 using HPLC/high-resolution mass spectrometry, and suggested analytical strategies for detection in plasma and urine using HPLC/low-resolution triple-quadrupole mass spectrometry. (PMIDs: 22962027) [PMID 22962027]
An analytical methods study investigated adsorption effects of doping-relevant peptides and reported that recovery of TB-500 from different surfaces depended on consumable selection and the peptide’s physico/chemical features. (PMIDs: 28887173) [PMID 28887173]
A review of emerging therapeutics in human doping controls summarized analytical approaches for detecting peptidic low- and high-molecular-mass compounds including TB-500 in blood or urine, in the context of expanding doping-control capabilities. (PMIDs: 24906629) [PMID 24906629]
Vendor test rankings (29)
Vendors ranked by their independent third-party test grade for TB-500, attributed to Finnrick. The grade is their verdict, not ours.
Real third-party HPLC results aggregated from Peptigrity, each attributed to the lab that ran it — average purity 99.4% across 437 tests. Not our verdict.
Ho EN, Kwok WH, Lau MY, Wong AS, Wan TS, Lam KK · Journal of chromatography. A · 2012 · PMID 23084823
FAQ
What is TB-500?
TB-500 (TB500, 885340-08-9, UNII-QHK6Z47GTG) is classified under repair & thymosin peptides, sold for research use only and not approved for human consumption. Research goals associated with it include recovery & tissue repair.
Is TB-500 FDA-approved?
No. TB-500 is sold for research use only and is not approved for human consumption.
What does the research on TB-500 say?
peptideone aggregates 8 references from PubMed for TB-500. The summary on this page digests them with citations; we summarize sources and make no efficacy claims.