TB-500
Status unknownAlso 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.
What the research says
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]
Independent test grades (16 vendors)
Aggregated from Finnrick (independent testing). Their grades, attributed — not our verdict.
| Vendor | Grade | Score |
|---|---|---|
| Yabang Peptide | A | 9.2 |
| NuLife Peptides | A | 9.0 |
| Peptide Partners | A | 8.1 |
| Yiwu Aozuo Trading Co | C | 8.1 |
| Reta-Peptide | E | 6.5 |
| Nexaph | B | 6.2 |
| LiliPeptide | D | 6.0 |
| Yimei | E | 5.8 |
| TSC Top Supplements China | C | 5.8 |
| ZLZ Peptide | E | 5.2 |
| Shanghai Sigma Audley SSA | F | 5.0 |
| SRY Labs | E | 5.0 |
| Tianjin Ruiwang New Material Technology Co | E | 4.9 |
| Qing Li Peptide | E | 4.9 |
| Wuhan Wansheng Biotechnology | F | 4.9 |
| HK Peptides | E | 4.9 |
Research literature (8)
Consolidated from PubMed — each links to the original record.
- Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.
Mayfield CK, Bolia IK, Feingold CL, Lin EH, Liu JN, Rick Hatch GF · The American journal of sports medicine · 2026 · PMID 41476424
- Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.
Rahman OF, Lee SJ, Seeds WA · Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews · 2026 · PMID 41490200
- Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
Mendias CL, Awan TM · Sports medicine (Auckland, N.Z.) · 2026 · PMID 41966639
- Therapeutic peptides in gerontology: mechanisms and applications for healthy aging.
Mavrych V, Shypilova I, Bolgova O · Frontiers in aging · 2026 · PMID 42021992
- Adsorption effects of the doping relevant peptides Insulin Lispro, Synachten, TB-500 and GHRP 5.
Judák P, Van Eenoo P, Deventer K · Analytical biochemistry · 2017 · PMID 28887173
- Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls.
Thevis M, Schänzer W · Journal of pharmaceutical and biomedical analysis · 2014 · PMID 24906629
- Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential.
Esposito S, Deventer K, Goeman J, Van der Eycken J, Van Eenoo P · Drug testing and analysis · 2012 · PMID 22962027
- Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry.
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. Research goals associated with it include recovery & tissue repair.
- Is TB-500 FDA-approved?
- The regulatory status of TB-500 is not established in our sources.
- 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.