{"product_id":"tb-500-10mg","title":"TB-500 10mg","description":"\u003ch2\u003eCompound Overview\u003c\/h2\u003e\u003cdiv style=\"background:#fff7e6;border:1px solid #eeddbc;border-left:4px solid #8a6318;border-radius:14px;padding:16px 18px;margin:0 0 22px\"\u003e\n\u003cp style=\"margin:0 0 8px;font-size:15px;color:#8a6318;font-weight:600\"\u003eIndependent certificate published — in stock\u003c\/p\u003e\n\u003cp style=\"margin:0;font-size:15px;color:#5a4a1e;line-height:1.65\"\u003eThis lot has been independently assayed. Lot tb50010-0626-01 measured \u003cstrong\u003eHPLC 99.766% purity and 11.99 mg peptide content\u003c\/strong\u003e (Janoshik report #147070). The independent certificate of analysis — HPLC-UV purity with mass-spectrometric identity confirmation — is published with its lot number on our \u003ca href=\"\/pages\/lab-results\"\u003elab results page\u003c\/a\u003e; our confirmatory Testides test on this lot is still in progress. We do not list purity numbers we have not measured.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#16201a\"\u003e\u003cstrong\u003eTB-500 is a synthetic, N-terminally acetylated seven-residue peptide, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ), corresponding to residues 17–23 of the 43-residue regulatory protein thymosin β4 (Tβ4). It is supplied here as lyophilised powder for laboratory research use only — a defined reference material for in-vitro work on actin dynamics, cell migration and tissue-repair signalling.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003eThe single most important thing to understand about this compound is on the label, and almost no vendor states it plainly: \u003cstrong style=\"color:#16201a\"\u003eTB-500 and thymosin β4 are not the same molecule\u003c\/strong\u003e. Thymosin β4 is a full 43-amino-acid protein — roughly 4,921 Da, CAS 77591-33-4 — found in nearly every mammalian cell and in blood and wound fluid, where it is the principal actin-sequestering peptide. \"TB-500,\" by its most precise and most commonly cited definition, is a far smaller synthetic fragment: the acetylated heptapeptide Ac-LKKTETQ, roughly 889 Da, CAS 885340-08-9, reproducing only the central actin-binding region of the parent protein. One is a cytokine-sized regulatory protein; the other is a short peptide a fraction of its mass. Treating published Tβ4 data as though it were TB-500 data — which much of the market does — is the central error this page exists to correct.\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003eThe name also sits on a real research distinction. The conserved motif \u003cstrong style=\"color:#16201a\"\u003eLKKTET\u003c\/strong\u003e is the hexapeptide shared across the β-thymosin family and has been mapped as central to how thymosin β4 contacts monomeric actin (Van Troys et al., \u003cem\u003eEMBO J\u003c\/em\u003e 1996;15(2):201–210, PMID 8617196). TB-500 extends that motif by one glutamine (LKKTET\u003cstrong\u003eQ\u003c\/strong\u003e) and caps the N-terminus with an acetyl group, giving the heptapeptide marketed and sold as \"TB-500.\" So the fragment is not an arbitrary cut — it is built around the actin-binding sequence. What it is \u003cem\u003enot\u003c\/em\u003e is a complete stand-in for the whole protein, and that caveat runs through everything below.\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003e\u003cstrong style=\"color:#16201a\"\u003eWhat thymosin β4 does at the molecular level is well characterised.\u003c\/strong\u003e It binds globular (monomeric, G-) actin in a roughly 1:1 complex and holds a large intracellular reserve of unpolymerised actin — in some motile cells Tβ4 is present at tens to hundreds of micromolar, buffering a substantial fraction of the free G-actin pool. When a cell receives a migration or repair cue, that sequestered actin can be released for rapid filament (F-actin) assembly at the leading edge. By tuning the monomer reserve, Tβ4 influences cytoskeletal remodelling, directed cell migration, and downstream programmes including angiogenesis and matrix turnover. This is the mechanism investigators have studied in wound re-epithelialisation, corneal repair and post-infarction cardiac models (reviewed in Goldstein, Hannappel \u0026amp; Kleinman, \u003cem\u003eTrends Mol Med\u003c\/em\u003e 2005;11(9):421–429, PMID 16099219; and Goldstein, Hannappel, Sosne \u0026amp; Kleinman, \u003cem\u003eExpert Opin Biol Ther\u003c\/em\u003e 2012;12(1):37–51, PMID 22074294).\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003e\u003cstrong style=\"color:#16201a\"\u003eThe honest nuance is about the fragment specifically.\u003c\/strong\u003e The isolated LKKTET\/LKKTETQ region is necessary for and central to actin binding, and synthetic peptides containing the actin-binding domain have reproduced several of the parent protein's regenerative activities in defined assays — for example promoting dermal wound repair in diabetic and aged mice (Philp et al., \u003cem\u003eWound Repair Regen\u003c\/em\u003e 2003;11(1):19–24, PMID 12581422). But the short peptide binds actin far more weakly than the intact protein, and it lacks domains of Tβ4 that carry other activities entirely — notably the N-terminal \u003cstrong style=\"color:#16201a\"\u003eAc-SDKP\u003c\/strong\u003e tetrapeptide (residues 1–4, also called seraspenide) associated with anti-fibrotic and anti-inflammatory effects, and the N-terminal helical region linked to cytoprotection. So \"TB-500 reproduces the actin-binding activity of thymosin β4\" is defensible; \"TB-500 does everything thymosin β4 does\" is not.\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003e\u003cstrong style=\"color:#16201a\"\u003eThe landmark tissue-repair studies used the full protein.\u003c\/strong\u003e Full-length Tβ4 accelerated skin wound healing with increased re-epithelialisation and vessel density (Malinda et al., \u003cem\u003eJ Invest Dermatol\u003c\/em\u003e 1999;113(3):364–368, PMID 10469335); activated integrin-linked kinase and Akt to promote cardiomyocyte survival and migration and reduce scarring after coronary ligation in mice (Bock-Marquette et al., \u003cem\u003eNature\u003c\/em\u003e 2004;432(7016):466–472, PMID 15565145); and mobilised adult epicardial progenitors to drive neovascularisation (Smart et al., \u003cem\u003eNature\u003c\/em\u003e 2007;445(7124):177–182, PMID 17108969). Human work has likewise used the full peptide: phase 1 intravenous safety in healthy volunteers (Ruff et al., \u003cem\u003eAnn N Y Acad Sci\u003c\/em\u003e 2010, PMID 20536472) and ophthalmic formulations (RGN-259 eye drops) taken into phase 2\/3 trials for dry eye and neurotrophic keratopathy (e.g. NCT03937882; PMID 36613994). Where a finding on this page belongs to full Tβ4 rather than the Ac-LKKTETQ fragment, we say so.\u003c\/p\u003e\n\n\u003cp style=\"margin:0 0 16px;font-size:15px;line-height:1.65;color:#5a6157\"\u003e\u003cstrong style=\"color:#16201a\"\u003eThe honest regulatory frame.\u003c\/strong\u003e Neither TB-500 nor thymosin β4 is an approved drug anywhere. There is no Health Canada authorisation and \u003cstrong style=\"color:#16201a\"\u003eno Drug Identification Number\u003c\/strong\u003e; no FDA or EMA approval. Health Canada named \u003cstrong\u003eTB-500 specifically\u003c\/strong\u003e in its public advisory of 9 April 2026 (identification number RA-81874) warning against peptides bought online, alongside BPC-157, GHK-Cu, MOTS-c and others — and stated that labelling a product \"for research use only\" does not make it legal to sell for injection. Thymosin β4 and its fragments are also \u003cstrong\u003eprohibited in sport\u003c\/strong\u003e under the World Anti-Doping Agency framework (growth-factor class), and TB-500 has repeatedly been detected as a doping agent in racehorses. None of the published research supports a human therapeutic claim, and we make none.\u003c\/p\u003e\n\n\u003cp style=\"margin:0;font-size:15px;line-height:1.65;color:#5a6157\"\u003eWe sell this vial as a laboratory reagent and nothing else. It pairs naturally with our \u003ca href=\"\/products\/bpc-157-10mg\"\u003eBPC-157\u003c\/a\u003e for comparative tissue-repair work and appears alongside BPC-157 in our \u003ca href=\"\/products\/healing-blend-10mg-bpc-157-tb-500\"\u003ehealing (\"Wolverine\") blend\u003c\/a\u003e; related reagents in this area include \u003ca href=\"\/products\/ghk-cu-50mg\"\u003eGHK-Cu\u003c\/a\u003e, the \u003ca href=\"\/products\/glow-blend\"\u003eglow blend\u003c\/a\u003e and \u003ca href=\"\/products\/mots-c-10mg\"\u003eMOTS-c\u003c\/a\u003e. For reconstitution we stock \u003ca href=\"\/products\/bacteriostatic-water-3ml\"\u003ebacteriostatic water\u003c\/a\u003e. See the \u003ca href=\"\/pages\/peptide-library\"\u003epeptide library\u003c\/a\u003e for comparative context and \u003ca href=\"\/pages\/lab-results\"\u003elab results\u003c\/a\u003e for certificates as lots are released. For the published literature on the fragment and on full-length thymosin β4, see \u003ca href=\"\/blogs\/research\/tb-500-canada\"\u003ethe TB-500 research guide\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cdiv style=\"margin-top:20px;margin-bottom:4px;padding:14px 16px;background:#f0faf5;border-left:4px solid #0f6e56;border-radius:0 8px 8px 0\"\u003e\u003cp style=\"margin:0;font-size:14px;color:#1a1a1a\"\u003e\u003cstrong\u003eFor laboratory and research use only.\u003c\/strong\u003e Not for human consumption, veterinary use, or therapeutic application. Not approved by Health Canada. We do not provide preparation, dilution or administration guidance for any compound we sell.\u003c\/p\u003e\u003c\/div\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCompound\u003c\/th\u003e\n\u003ctd\u003eTB-500 — thymosin β4 active fragment, Ac-LKKTETQ, lyophilised powder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSynonyms \/ fragment note\u003c\/th\u003e\n\u003ctd\u003eThymosin β4 (17–23); Ac-LKKTETQ; TB-500 acetate; Tβ4 actin-binding-domain peptide. \u003cem\u003e\"TB-500\" most precisely denotes the acetylated heptapeptide Ac-LKKTETQ, \u003cstrong\u003enot\u003c\/strong\u003e full-length thymosin β4. Many suppliers sell the full 43-residue protein under the \"TB-500\" name — confirm the exact sequence and molecular weight before comparing any data or price.\u003c\/em\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCompound class\u003c\/th\u003e\n\u003ctd\u003eSynthetic acetylated peptide fragment; actin-binding-domain peptide of the β-thymosin family (research reference material)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCAS number\u003c\/th\u003e\n\u003ctd\u003e885340-08-9 (TB-500 \/ Ac-LKKTETQ fragment and acetate salt). \u003cem\u003eDo not confuse with CAS 77591-33-4, which is full-length thymosin β4 — a different molecule with a different formula and weight.\u003c\/em\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eMolecular formula\u003c\/th\u003e\n\u003ctd\u003eC\u003csub\u003e38\u003c\/sub\u003eH\u003csub\u003e68\u003c\/sub\u003eN\u003csub\u003e10\u003c\/sub\u003eO\u003csub\u003e14\u003c\/sub\u003e (fragment free peptide); acetate salt adds ·\u003cem\u003ex\u003c\/em\u003eC\u003csub\u003e2\u003c\/sub\u003eH\u003csub\u003e4\u003c\/sub\u003eO\u003csub\u003e2\u003c\/sub\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eMolecular weight\u003c\/th\u003e\n\u003ctd\u003e889.0 Da (average; 889.018 g\/mol for the free peptide)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSequence\u003c\/th\u003e\n\u003ctd\u003eAc-Leu-Lys-Lys-Thr-Glu-Thr-Gln (one-letter: Ac-LKKTETQ)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePeptide length\u003c\/th\u003e\n\u003ctd\u003e7 residues (heptapeptide); N-terminally acetylated, free C-terminal acid\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSalt \/ counter-ion\u003c\/th\u003e\n\u003ctd\u003eSupplied as the acetate salt\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eAppearance\u003c\/th\u003e\n\u003ctd\u003eWhite to off-white lyophilised powder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePubChem CID\u003c\/th\u003e\n\u003ctd\u003e62707662\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eUNII\u003c\/th\u003e\n\u003ctd\u003eQHK6Z47GTG (ChemSpider 72380051; InChIKey ADKDNDYYIZUVCZ-ZQNQAVPYSA-N)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eParent molecule (for cross-reference)\u003c\/th\u003e\n\u003ctd\u003eThymosin β4 — 43 residues, Ac-SDKPDMAEIEKFDKSK\u003cstrong\u003eLKKTETQ\u003c\/strong\u003eEKNPLPSKETIEQEKQAGES, ≈4,921 Da, CAS 77591-33-4 (the LKKTET motif at residues 17–22 is the actin-binding region the fragment is drawn from)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eResearch applications\u003c\/th\u003e\n\u003ctd\u003e\n\u003cem\u003eIn-vitro\u003c\/em\u003e study of G-actin sequestration and actin polymerisation; cell-migration and motility assays (endothelial, keratinocyte, fibroblast); angiogenesis and endothelial-signalling models; wound re-epithelialisation and extracellular-matrix-remodelling \/ MMP models; corneal and cardiac tissue-repair research; comparative actin-binding-domain studies against full-length Tβ4; LC-MS\/MS identity, purity and metabolite method development\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eAssay status\u003c\/th\u003e\n\u003ctd\u003eIndependently assayed by HPLC; certificate published (Janoshik #147070); Testides confirmation in progress\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCost per mg\u003c\/th\u003e\n\u003ctd\u003e$6.50 per mg ($64.99 \/ 10 mg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eStorage\u003c\/th\u003e\n\u003ctd\u003eLyophilised powder at −20 °C, desiccated and protected from light; reconstituted solution 2–8 °C for short-term use and ≤ −20 °C for longer holding; aliquot and avoid repeated freeze–thaw cycles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eRelated compounds\u003c\/th\u003e\n\u003ctd\u003e\n\u003ca href=\"\/products\/bpc-157-10mg\"\u003eBPC-157 10mg\u003c\/a\u003e · \u003ca href=\"\/products\/healing-blend-10mg-bpc-157-tb-500\"\u003eHealing (Wolverine) Blend — BPC-157 + TB-500\u003c\/a\u003e · \u003ca href=\"\/products\/ghk-cu-50mg\"\u003eGHK-Cu 50mg\u003c\/a\u003e · \u003ca href=\"\/products\/glow-blend\"\u003eGlow Blend\u003c\/a\u003e · \u003ca href=\"\/products\/mots-c-10mg\"\u003eMOTS-c 10mg\u003c\/a\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eShips from\u003c\/th\u003e\n\u003ctd\u003eBritish Columbia, Canada — free tracked shipping Canada-wide, dispatched within 48 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eRegulatory status\u003c\/th\u003e\n\u003ctd\u003eInvestigational. Not approved by Health Canada, the FDA, the EMA or any other regulator. No DIN. Named in the Health Canada advisory of 9 April 2026 (RA-81874). Prohibited in sport under WADA (growth-factor class)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eIntended use\u003c\/th\u003e\n\u003ctd\u003eLaboratory research only — \u003cem\u003ein vitro\u003c\/em\u003e and preclinical. Not a drug, supplement or food; not for human or veterinary use, diagnosis or treatment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cdetails\u003e\u003csummary\u003eWhat exactly is TB-500 — and is it the same as thymosin β4?\u003c\/summary\u003e\u003cp\u003eNo — and this is the distinction that matters most before you compare any datasheet or price. \u003cstrong\u003eThymosin β4 (Tβ4)\u003c\/strong\u003e is the full endogenous protein: 43 amino acids, approximately 4,921 Da, CAS 77591-33-4, present in almost every mammalian cell and in blood and wound fluid, where it is the principal actin-sequestering peptide. \u003cstrong\u003eTB-500\u003c\/strong\u003e, by its most precise and most widely cited definition, is a synthetic fragment of that protein: the N-terminally acetylated heptapeptide \u003cstrong\u003eAc-LKKTETQ\u003c\/strong\u003e (Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln), roughly 889 Da, CAS 885340-08-9, corresponding to residues 17–23 of Tβ4.\u003c\/p\u003e\n\u003cp\u003eSo the two are related the way a sentence is related to a paragraph it was lifted from. The fragment is built around the conserved \u003cstrong\u003eLKKTET\u003c\/strong\u003e motif — the β-thymosin actin-binding sequence mapped by Van Troys and colleagues (\u003cem\u003eEMBO J\u003c\/em\u003e 1996;15(2):201–210) — extended by one glutamine and acetyl-capped. It reproduces the actin-binding portion of the parent protein while being far smaller and cheaper to synthesise. What it does not reproduce are the other functional regions of the full protein, including the N-terminal Ac-SDKP tetrapeptide linked to anti-fibrotic activity. A large fraction of the market blurs this by selling the full 43-residue protein as \"TB-500,\" so before buying or citing anything, confirm the exact sequence and molecular weight: ~889 Da is the fragment; ~4,921 Da is the whole protein. This vial is the fragment, Ac-LKKTETQ, supplied for laboratory research only.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhich molecule did the published research actually use — the fragment or full thymosin β4?\u003c\/summary\u003e\u003cp\u003eThis is the question that separates honest sourcing from marketing, and the answer is uncomfortable for most \"TB-500\" listings: \u003cstrong\u003ethe great majority of the influential published research used full-length thymosin β4, not the Ac-LKKTETQ heptapeptide.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe landmark wound-healing paper (Malinda et al., \u003cem\u003eJ Invest Dermatol\u003c\/em\u003e 1999;113(3):364–368) used the full protein. The two \u003cem\u003eNature\u003c\/em\u003e cardiac papers that made Tβ4 famous — integrin-linked kinase activation and cardiomyocyte survival after infarction (Bock-Marquette et al., 2004;432(7016):466–472) and adult epicardial progenitor mobilisation (Smart et al., 2007;445(7124):177–182) — used the full protein. Human phase 1 safety (Ruff et al., \u003cem\u003eAnn N Y Acad Sci\u003c\/em\u003e 2010) and the RGN-259 ophthalmic trials used the full protein. When a product page attributes \"accelerated healing\" or \"cardiac repair\" to TB-500, it is almost always borrowing full-Tβ4 data.\u003c\/p\u003e\n\u003cp\u003eThere \u003cem\u003eis\u003c\/em\u003e genuine fragment-specific evidence, and it is narrower. Philp and colleagues (\u003cem\u003eWound Repair Regen\u003c\/em\u003e 2003;11(1):19–24) showed that a synthetic peptide containing the actin-binding domain promoted dermal wound repair in diabetic and aged mice, reproducing part of the parent protein's effect. More recent analytical work has characterised TB-500 the heptapeptide and its rapid metabolism specifically. The honest rule we apply on this page: where a finding belongs to full Tβ4, it is labelled as full Tβ4; where it belongs to the fragment, it is labelled as the fragment. An efficacy claim that quietly swaps one for the other is not evidence about the molecule in this vial.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat does TB-500 \/ thymosin β4 do at the molecular level (actin binding)?\u003c\/summary\u003e\u003cp\u003eThe core mechanism is \u003cstrong\u003eG-actin sequestration\u003c\/strong\u003e. Actin exists in two forms: free monomers (globular, or G-actin) and polymerised filaments (F-actin). Cell movement, division and shape change all depend on rapidly assembling and disassembling filaments, which means a cell needs a controlled reserve of monomer ready to deploy. Thymosin β4 is the main peptide that supplies and regulates that reserve.\u003c\/p\u003e\n\u003cp\u003eFull Tβ4 binds a single molecule of monomeric actin in a roughly \u003cstrong\u003e1:1 complex\u003c\/strong\u003e, holding it in a non-polymerisable state. In motile cells Tβ4 is abundant — present at tens to hundreds of micromolar — so it buffers a large share of the free G-actin pool. When a migration or repair signal arrives, sequestered monomer is released and fed onto growing filaments at the leading edge, letting the cell extend and move. By setting the size of this buffered monomer pool, Tβ4 tunes cytoskeletal remodelling, directed cell migration toward injury, and downstream programmes that depend on it — endothelial migration in angiogenesis, keratinocyte migration in re-epithelialisation, and extracellular-matrix remodelling.\u003c\/p\u003e\n\u003cp\u003eThe physical contact point is the \u003cstrong\u003eLKKTET\u003c\/strong\u003e motif, the conserved β-thymosin sequence mapped to the actin interface by mutational analysis (Van Troys et al., \u003cem\u003eEMBO J\u003c\/em\u003e 1996;15(2):201–210). That is exactly the region the TB-500 fragment (Ac-LKKTET\u003cstrong\u003eQ\u003c\/strong\u003e) is drawn from, which is why the fragment carries actin-binding character at all. Downstream, full Tβ4's repair effects have been tied to integrin-linked kinase and Akt signalling in the cardiac work (Bock-Marquette et al., \u003cem\u003eNature\u003c\/em\u003e 2004). For a general mechanistic overview, Goldstein, Hannappel and Kleinman's reviews (\u003cem\u003eTrends Mol Med\u003c\/em\u003e 2005;11(9):421–429; \u003cem\u003eExpert Opin Biol Ther\u003c\/em\u003e 2012;12(1):37–51) are the standard references.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eDoes the isolated Ac-LKKTETQ heptapeptide really sequester actin as strongly as the full protein?\u003c\/summary\u003e\u003cp\u003eThis is where honest sourcing earns its keep, because the usual shorthand — \"TB-500 is the active site, so it does what Tβ4 does\" — overstates the case. The accurate position is more careful.\u003c\/p\u003e\n\u003cp\u003eThe LKKTET motif is \u003cstrong\u003enecessary for and central to\u003c\/strong\u003e actin binding: mutational mapping places the actin contact in this region (Van Troys et al., \u003cem\u003eEMBO J\u003c\/em\u003e 1996). But the same structural work shows that high-affinity binding of the intact protein also involves its N-terminal segment and an α-helical region flanking the motif. Strip the protein down to a short acetylated hexa- or heptapeptide and you keep the recognition sequence but lose much of the surrounding structure, so the isolated fragment binds monomeric actin \u003cstrong\u003efar more weakly\u003c\/strong\u003e than full Tβ4. It is a reduced mimic, not an equal substitute, for the quantitative actin-sequestering capacity of the whole molecule.\u003c\/p\u003e\n\u003cp\u003eWhat the fragment \u003cem\u003ehas\u003c\/em\u003e been shown to do is reproduce specific downstream activities in defined assays — for instance, a synthetic actin-binding-domain peptide promoted dermal wound repair in diabetic and aged mice (Philp et al., \u003cem\u003eWound Repair Regen\u003c\/em\u003e 2003;11(1):19–24). That is a real result about the fragment. It is not the same claim as \"the heptapeptide sequesters actin with the affinity of the native protein,\" which the biophysics does not support. For a research reagent this distinction is practical: an assay that assumes the fragment behaves stoichiometrically like intact Tβ4 — the same 1:1 buffering at the same concentrations — will misread its data. If your experiment depends on quantitative actin sequestration, the full protein and the fragment are not interchangeable inputs, and we will not pretend they are.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat has actually been published on TB-500 \/ thymosin β4, and how strong is the evidence?\u003c\/summary\u003e\u003cp\u003eThe published record is real, is mostly preclinical, and is mostly about the full protein. Taken in order:\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMechanism.\u003c\/strong\u003e Van Troys et al. (\u003cem\u003eEMBO J\u003c\/em\u003e 1996;15(2):201–210) mapped the actin-binding site to the LKKTET region. Goldstein, Hannappel and Kleinman reviewed the actin-sequestering-to-tissue-repair biology (\u003cem\u003eTrends Mol Med\u003c\/em\u003e 2005;11(9):421–429; \u003cem\u003eExpert Opin Biol Ther\u003c\/em\u003e 2012;12(1):37–51).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWound healing.\u003c\/strong\u003e Full Tβ4 accelerated re-epithelialisation and increased vessel density in rodent skin wounds (Malinda et al., \u003cem\u003eJ Invest Dermatol\u003c\/em\u003e 1999;113(3):364–368). A synthetic actin-binding-domain peptide — fragment-level evidence — promoted repair in diabetic and aged mice (Philp et al., \u003cem\u003eWound Repair Regen\u003c\/em\u003e 2003;11(1):19–24).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCardiac.\u003c\/strong\u003e Full Tβ4 activated integrin-linked kinase and Akt, promoting cardiomyocyte survival and migration and reducing scar after coronary ligation in mice (Bock-Marquette et al., \u003cem\u003eNature\u003c\/em\u003e 2004;432(7016):466–472), and mobilised adult epicardial progenitors to drive neovascularisation (Smart et al., \u003cem\u003eNature\u003c\/em\u003e 2007;445(7124):177–182).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHuman.\u003c\/strong\u003e Full Tβ4 reached phase 1 intravenous safety testing in healthy volunteers (Ruff et al., \u003cem\u003eAnn N Y Acad Sci\u003c\/em\u003e 2010) and early ophthalmic trials (RGN-259 eye drops) for dry-eye disease and neurotrophic keratopathy (e.g. NCT03937882; PMID 36613994). \u003cstrong\u003eHow strong is this?\u003c\/strong\u003e Preclinical signals are consistent and mechanistically coherent; human data are limited to early-phase safety and small ophthalmic studies, with no large outcome trials and no approved indication. The evidence supports studying actin-dependent repair biology — not a human therapeutic claim.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat does the evidence NOT support?\u003c\/summary\u003e\u003cp\u003eJust as important as what is published is what is not, and a reagent vendor has an obligation to state the gaps rather than paper over them.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIt does not support a human therapeutic claim.\u003c\/strong\u003e There is no approved indication for TB-500 or thymosin β4 in any country. Human data are confined to early-phase safety and small ophthalmic trials; there are no large randomised outcome trials for wound healing, injury recovery, muscle, tendon or cardiac endpoints, and no mortality or long-term safety data.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIt does not support equating the fragment with the full protein.\u003c\/strong\u003e Most headline findings are full-Tβ4 results. The isolated Ac-LKKTETQ heptapeptide binds actin far more weakly than the intact protein and lacks the Ac-SDKP and N-terminal regions that carry Tβ4's anti-fibrotic and cytoprotective activities, so fragment efficacy cannot simply be read off full-protein studies.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIt does not support \"systemic healing\" extrapolations.\u003c\/strong\u003e Accelerated re-epithelialisation in a mouse wound or reduced scar in a ligated mouse heart are specific model readouts; they are not evidence of whole-body tendon, ligament or \"recovery\" benefit in any species, and certainly not in humans.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIt raises an unresolved angiogenesis caution.\u003c\/strong\u003e Because the biology is pro-angiogenic and pro-migratory, a theoretical concern about tumour vascularisation has been raised in the literature; published sources note no demonstrated human cancer link, but the question is open rather than closed. And the fragment is \u003cstrong\u003epharmacokinetically short-lived\u003c\/strong\u003e — analytical studies show TB-500 the heptapeptide is rapidly metabolised — so in-vitro exposure and any in-vivo exposure are not comparable. None of these gaps is a reason to avoid the compound as a research reagent; they are reasons not to overstate it.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eTB-500 vs BPC-157 as research reagents — how do they compare?\u003c\/summary\u003e\u003cp\u003eThey are frequently studied together in tissue-repair models, but they are structurally and mechanistically distinct compounds, and conflating them is a common error.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTB-500\u003c\/strong\u003e is the acetylated heptapeptide Ac-LKKTETQ (CAS 885340-08-9, ~889 Da), the actin-binding fragment of thymosin β4. Its proposed mechanism runs through \u003cstrong\u003eactin dynamics\u003c\/strong\u003e: G-actin sequestration by the parent protein, modulation of the monomer reserve, and the resulting effects on cytoskeletal remodelling, directed cell migration and angiogenesis.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBPC-157\u003c\/strong\u003e is a synthetic 15-residue peptide (a \"pentadecapeptide\") derived from a sequence identified in human gastric juice (Body Protection Compound). Its research literature centres on a different set of pathways — angiogenic signalling associated with the VEGFR2\/eNOS axis, nitric-oxide-system interactions, and models of tendon, ligament, muscle and gastrointestinal repair — rather than on actin sequestration.\u003c\/p\u003e\n\u003cp\u003eBecause the two propose \u003cem\u003edifferent\u003c\/em\u003e upstream mechanisms that could plausibly converge on the shared endpoints of angiogenesis and tissue repair, they are often run side by side or in combination — which is exactly the rationale for our \u003ca href=\"\/products\/healing-blend-10mg-bpc-157-tb-500\"\u003ehealing (\"Wolverine\") blend\u003c\/a\u003e that contains both. For a clean comparative experiment, the useful design is to run standalone \u003ca href=\"\/products\/bpc-157-10mg\"\u003eBPC-157\u003c\/a\u003e, standalone TB-500, and the combination against the same assay, so the contribution of each mechanism can be separated. One caution shared by both: neither is an approved drug, both appear on the same Health Canada advisory, and comparisons here are for research context only — not a ranking of therapeutic value, which neither compound has established.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow does standalone TB-500 relate to your Wolverine healing blend?\u003c\/summary\u003e\u003cp\u003eThey are different products for different experiments. This listing is \u003cstrong\u003estandalone TB-500\u003c\/strong\u003e — the single compound Ac-LKKTETQ, supplied on its own as a defined reference material. Our \u003ca href=\"\/products\/healing-blend-10mg-bpc-157-tb-500\"\u003ehealing (\"Wolverine\") blend\u003c\/a\u003e is a \u003cstrong\u003ecombination product\u003c\/strong\u003e containing both BPC-157 and TB-500 in a single vial.\u003c\/p\u003e\n\u003cp\u003eChoose the standalone when you need to attribute an effect to one mechanism. If an assay is meant to probe actin-dependent migration, or to characterise the Ac-LKKTETQ fragment specifically — its identity, purity, concentration-response or metabolism — then a single-compound vial is the correct input, because a blend confounds the two peptides and makes it impossible to say which drove the result.\u003c\/p\u003e\n\u003cp\u003eChoose the blend when the experimental question is explicitly about the \u003cem\u003ecombination\u003c\/em\u003e — for example comparing a two-peptide mixture against each peptide alone on a shared repair endpoint. In a properly designed comparative study you would typically want all three arms available: standalone \u003ca href=\"\/products\/bpc-157-10mg\"\u003eBPC-157\u003c\/a\u003e, standalone TB-500 (this page), and the combined blend, each assayed against the same model. Note that the nickname \"Wolverine\" is informal vendor shorthand for the combination; it is not a pharmacological designation and implies nothing about healing capacity in any organism. Both the blend and the standalone are sold strictly for laboratory research use only.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhy are there two CAS numbers — 885340-08-9 and 77591-33-4 — and why does it matter for my data?\u003c\/summary\u003e\u003cp\u003eBecause they identify two different molecules, and mixing them up corrupts both your chemistry records and any literature comparison you build on them.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCAS 885340-08-9\u003c\/strong\u003e is the TB-500 fragment: Ac-LKKTETQ, molecular formula C\u003csub\u003e38\u003c\/sub\u003eH\u003csub\u003e68\u003c\/sub\u003eN\u003csub\u003e10\u003c\/sub\u003eO\u003csub\u003e14\u003c\/sub\u003e, average mass about 889 Da, PubChem CID 62707662, UNII QHK6Z47GTG. That is the compound on this page.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCAS 77591-33-4\u003c\/strong\u003e is full-length thymosin β4: the 43-residue protein, sequence Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES, average mass about 4,921 Da. That is a different substance with a different formula, a different mass, and a different PubChem record.\u003c\/p\u003e\n\u003cp\u003eWhy it matters in practice: a mass-spectrometry identity check expects ~889 Da for the fragment and ~4,921 Da for the protein, so the CAS\/formula\/mass you record must match what the instrument actually sees — a vial sold as \"TB-500\" that returns a ~4,921 Da parent ion is full Tβ4, however it is labelled. It also matters for citing literature: if you anchor a fragment experiment to full-Tβ4 papers (or vice versa) because both were filed under \"TB-500,\" your reference trail is wrong at the source. Our COA states the molecular weight and the identity method, so the number on the certificate can be matched to the molecule you intend to study. If a supplier cannot tell you which CAS number, formula and mass their \"TB-500\" corresponds to, that is the whole problem in miniature.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eIs TB-500 legal in Canada, and is it prohibited in sport?\u003c\/summary\u003e\u003cp\u003e\u003cstrong\u003eTB-500 is not an approved product in Canada.\u003c\/strong\u003e It has no Health Canada authorisation, \u003cstrong\u003eno Drug Identification Number (DIN)\u003c\/strong\u003e, and is not approved by the FDA, the EMA or any other regulator. It is an investigational research chemical, sold here strictly for laboratory research use — not as a drug, supplement or food, and not for human or veterinary use.\u003c\/p\u003e\n\u003cp\u003eHealth Canada named \u003cstrong\u003eTB-500 specifically\u003c\/strong\u003e in its public advisory of \u003cstrong\u003e9 April 2026\u003c\/strong\u003e (identification number RA-81874), \"Think twice before injecting peptides bought online,\" listing it alongside BPC-157, CJC-1295, GHK-Cu, ipamorelin, MOTS-c and others. The advisory states these products have not been assessed for safety, efficacy or quality, that selling them for human use is illegal in Canada, and — the sentence a research-peptide vendor has an obligation to reproduce rather than hide — that labelling a product \"for research use only\" \u003cstrong\u003edoes not make it legal\u003c\/strong\u003e to sell for injection. We sell this vial as a laboratory reagent and we do not sell it for administration to anyone, for any purpose.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn sport, it is prohibited.\u003c\/strong\u003e Thymosin β4 and its fragments fall under the World Anti-Doping Agency's prohibited growth-factor category, prohibited at all times (in and out of competition); TB-500 has repeatedly been identified as a doping agent in racehorses, and dedicated detection methods exist in equine and human anti-doping. Any athlete subject to anti-doping rules should treat TB-500 as prohibited. None of this is administration guidance — it is the regulatory status of the compound, which we state in full rather than bury.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow is identity and purity verified per lot, and where is the COA?\u003c\/summary\u003e\u003cp\u003ePer lot, by an independent laboratory — and the current lot's certificate is already published. Lot \u003cstrong\u003etb50010-0626-01\u003c\/strong\u003e was assayed by Janoshik (report #147070), returning \u003cstrong\u003e99.766% HPLC purity and 11.99 mg peptide content\u003c\/strong\u003e; our confirmatory Testides test on this lot is still in progress.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat the certificate reports:\u003c\/strong\u003e the current lot carries an \u003cstrong\u003eindependent certificate of analysis\u003c\/strong\u003e with two separate measurements. \u003cem\u003ePurity\u003c\/em\u003e is determined by HPLC-UV and reported as area-percent — the target peak's area divided by the total area of everything the detector sees — which for a short peptide like this counts truncations and related species in the denominator. \u003cem\u003eIdentity\u003c\/em\u003e is confirmed by mass spectrometry: for the Ac-LKKTETQ fragment the expected average mass is about 889 Da, and the MS result is what distinguishes the genuine heptapeptide from full-length thymosin β4 (~4,921 Da) sold under the same name. The certificate carries its lot number so it can be matched to the vial in hand, and it is posted openly on our \u003ca href=\"\/pages\/lab-results\"\u003elab results page\u003c\/a\u003e, not held behind an email gate.\u003c\/p\u003e\n\u003cp\u003eWe publish no purity claim without a certificate behind it. A \"99%+\" figure with no lot number, no wavelength and no identity method is a marketing asset, not a record — and for this compound specifically, a purity number means little if the identity test was never run to confirm the vial contains the fragment rather than the full protein. For how to read a certificate like this one, see our guide on \u003ca href=\"\/blogs\/news\/how-to-read-peptide-coa\"\u003ehow to read a peptide COA\u003c\/a\u003e.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow should lyophilised TB-500 be stored and handled in the laboratory?\u003c\/summary\u003e\u003cp\u003e\u003cstrong\u003eLyophilised, sealed and desiccated: −20 °C for long-term holding, protected from light and moisture.\u003c\/strong\u003e The dry powder is the stable form and tolerates brief ambient exposure during shipping without meaningful loss, so the cold requirement applies to storage, not to the transit leg.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOn reconstitution\u003c\/strong\u003e, use an appropriate sterile solvent for laboratory handling (bacteriostatic or sterile water is conventional). Hold reconstituted solution at 2–8 °C for short-term use and at −20 °C or below for longer storage, and \u003cstrong\u003ealiquot before freezing\u003c\/strong\u003e: divide a stock into single-use volumes at first preparation so no working fraction is thawed more than once. Repeated freeze–thaw cycling is the most common avoidable cause of peptide loss. Do not return thawed material to the freezer.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eStructural notes specific to this sequence.\u003c\/strong\u003e Ac-LKKTETQ carries no methionine or cysteine, so the classic methionine-oxidation and disulfide-scrambling degradation routes do not apply. It does carry threonine, glutamate and a C-terminal glutamine, where deamidation and related hydrolytic chemistry are the plausible degradation pathways for a peptide of this type over time in solution. As a short, highly charged peptide it is water-soluble and less prone to interfacial aggregation than a long lipidated peptide, but good practice still avoids vigorous agitation of dilute stocks. These are general inferences from the sequence, not conclusions from a published stability study on this exact peptide — we have not seen one and do not quote a specific in-solution shelf life, because any such number would be unmeasured. Handle with standard laboratory PPE.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow fast do you ship, and is delivery free across Canada?\u003c\/summary\u003e\u003cp\u003eShipping is \u003cstrong\u003efree and tracked, Canada-wide, on every order, with no minimum\u003c\/strong\u003e. Orders are dispatched \u003cstrong\u003ewithin 48 hours\u003c\/strong\u003e, Monday to Friday, from our facility in \u003cstrong\u003eBritish Columbia\u003c\/strong\u003e. Because the vial is already in Canada there is no international leg, no customs clearance and no brokerage fee on a domestic order — the single most common source of delay and surprise cost when research peptides are ordered from overseas.\u003c\/p\u003e\n\u003cp\u003eOne point specific to this listing: TB-500 is \u003cstrong\u003ein stock and ships within 48 hours\u003c\/strong\u003e. The 48-hour dispatch commitment, the tracked shipping and the lot-matched certificate all apply now — the current lot's independent COA is already published. To see it, visit the \u003ca href=\"\/pages\/lab-results\"\u003elab results page\u003c\/a\u003e, where every current lot across the catalogue is indexed.\u003c\/p\u003e\n\u003cp\u003eWhen vials do ship, each one leaves \u003cstrong\u003esealed with its lot number printed on the label\u003c\/strong\u003e, so the number can be matched against the published certificate before the seal is ever broken — the same discipline we apply across the catalogue. Tracking is issued at the point of dispatch so a shipment can be followed from our facility to the delivery address. Current transit-time estimates by destination are maintained on our \u003ca href=\"\/pages\/shipping\"\u003eshipping page\u003c\/a\u003e, since carrier timelines change with season and region and we would rather link a live figure than quote a fixed one that goes stale.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat is your returns and refund policy?\u003c\/summary\u003e\u003cp\u003eReport any damage in transit or non-delivery to \u003ca href=\"mailto:info@thepeptide.ca\"\u003einfo@thepeptide.ca\u003c\/a\u003e \u003cstrong\u003ewithin 48 hours of the expected delivery date\u003c\/strong\u003e, with photographs of the packaging and the vial where applicable, and we will resolve it — a replacement or a refund, depending on the circumstance. Raising it promptly matters because carriers impose their own short windows for damage and loss claims, and a report that arrives weeks later is harder for anyone to act on.\u003c\/p\u003e\n\u003cp\u003eBecause these are sensitive research chemicals, the policy turns on whether the seal is intact. \u003cstrong\u003eSealed, unopened vials\u003c\/strong\u003e in their original packaging are eligible for exchange or replacement within \u003cstrong\u003e14 days\u003c\/strong\u003e of delivery in the case of shipping damage or an order error. \u003cstrong\u003eOpened or reconstituted vials cannot be returned.\u003c\/strong\u003e This is not a convenience rule: once a seal is broken we have no way to verify how the material was stored — what temperatures it saw, whether it was protected from light, whether it was reconstituted correctly — and a reagent of unknown handling history is not one we will put back into circulation for another researcher. The integrity that makes a lot worth buying is exactly what is lost once it has left our control and been opened.\u003c\/p\u003e\n\u003cp\u003eIf you are unsure whether a situation qualifies, contact support with your order number before taking any further step and we will review eligibility case by case. The complete terms, including the handling of partial orders and carrier-loss claims, are set out on our \u003ca href=\"\/policies\/refund-policy\"\u003erefund policy\u003c\/a\u003e page, which governs in any instance where this summary and the full policy differ.\u003c\/p\u003e\u003c\/details\u003e","brand":"ThePeptide","offers":[{"title":"Default Title","offer_id":50592979353670,"sku":"TB500-10MG","price":64.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0734\/3020\/4486\/files\/tb-500.png?v=1791516823","url":"https:\/\/thepeptide.ca\/products\/tb-500-10mg","provider":"ThePeptide","version":"1.0","type":"link"}