Key findings
- The first constituent has been examined in rat tendon explants and tendon fibroblasts, where outgrowth, migration and survival under oxidative stress rose while proliferation in the same assay did not. [1]
- The second constituent is a product name that analytical work resolved to Ac-LKKTETQ, the N-terminally acetylated 17 to 23 fragment of thymosin beta-4, so the amino acid sequence behind that half of the blend is itself a documentation question. [2][3]
- The two constituents were studied in different systems with different readouts, and neither cited paper examined them together, so no interaction between them is established here. [4][5]
Identity and structure
- Composition
- A mixture of two peptides. The amount of each constituent and the total fill come from the lot documentation; a combined mass alone does not give the amount of either one [6][2]
- First constituent
- The 15-residue sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val, written GEPPPGKPADDAGLV [6][7]
- Second constituent
- A product name resolved analytically to Ac-LKKTETQ, the N-terminally acetylated 17 to 23 fragment of thymosin beta-4, which is not the full-length protein [2][8]
- Name is not an analytical identity
- Material sold under the TB500 and TB1000 names was found not to be systematically consistent with the descriptions given for those names, so the blend name does not fix the second constituent [3]
- Form as supplied
- Sterile lyophilized powder
Mechanism as studied
For the first constituent the cited mechanism is cytoskeletal and vascular: phosphorylation of FAK and paxillin with induced F-actin formation in tendon fibroblasts, and raised VEGFR2 expression with receptor internalization in vascular endothelial cells, both measured in single-peptide experiments. [1][4]
For the second constituent the cited mechanism runs through the actin binding stretch of thymosin beta-4. A full-length variant lacking residues 17 to 23 showed no interaction with G-actin, and in human hepatic stellate cells the 17 to 23 peptide but not the 1 to 15 peptide blocked Akt phosphorylation and lowered proliferation and migration. That work used the unacetylated fragment. [8][5]
Research findings
Ex vivo
- System
- Rat Achilles tendon explants and tendon fibroblasts exposed to the first constituent alone
- Measured
- Outgrowth from explants, proliferation by MTT assay, survival under hydrogen peroxide stress, migration in a transwell filter assay, and FAK and paxillin phosphorylation
- Reported
- Outgrowth, survival under stress, migration and spreading rose, proliferation in the MTT assay did not change, and phosphorylation of FAK and paxillin rose while total protein amounts were unaltered. [1]
In vitro
- System
- Human vascular endothelial cells exposed to the first constituent alone, with a chick chorioallantoic membrane assay alongside
- Measured
- Endothelial tube formation, VEGFR2 and VEGF-A expression, VEGFR2 internalization with and without an endocytosis inhibitor, and VEGFR2-Akt-eNOS signalling
- Reported
- VEGFR2 expression and internalization rose while VEGF-A did not, and both the signalling activation and the tube formation increase were suppressed in the presence of the endocytosis inhibitor. [4]
Analytical
- System
- The TB-500 formulation alone, plus the same fragment prepared independently by solid phase peptide synthesis
- Measured
- Identification of the peptide present in the formulation by high performance liquid chromatography with high resolution mass spectrometry, and an analytical strategy for plasma and urine
- Reported
- The N-terminally acetylated 17 to 23 fragment of human thymosin beta-4, Ac-LKKTETQ, was detected and identified in the formulation, with the synthesized fragment supporting that identification. [2]
In vitro
- System
- Human hepatic stellate cell cultures stimulated with PDGF-BB and exposed to the unacetylated 17 to 23 peptide or the 1 to 15 peptide of thymosin beta-4, each alone
- Measured
- PDGF beta receptor, alpha smooth muscle actin and collagen 1 expression, Akt and PRAS40 phosphorylation, and proliferation and migration
- Reported
- The 17 to 23 peptide blocked the PDGF-BB driven rise in all three proteins, blunted Akt phosphorylation at both sites and lowered proliferation and migration, while the 1 to 15 peptide changed neither proliferation nor migration. [5]
Handling for in-vitro work
- Container surfaces in cited work
- Recovery of the second constituent from laboratory surfaces varied with the consumable used, and low-bind glassware and plasticware were not advantageous in every case [9]
- Storage
- Lyophilized at -20 °C, dark and dry; reconstituted aliquots kept cold and used promptly
Open questions
- No cited paper examines the two peptides together, so the composition, stability and any interaction of the mixture are unestablished here.
- The second constituent name has been found inconsistent with product content in the cited analytical work, so whether a lot contains the acetylated fragment, the unacetylated fragment or another thymosin material is a documentation question.
- The amount of each constituent and the total fill come from the lot documentation; a combined mass and a single headline purity figure answer neither question.
- The cited single-peptide studies use different cells, different stimuli and different readouts, so they offer no shared endpoint against which a mixture could be compared.
No clinical literature on this mixture is cited; the clinical literature attached to either constituent concerns finished formulations and is out of scope for a research material profile.
Lot records
Check the record for the exact material you order. A published paper and a batch certificate answer different questions.
- RV-24-0038-2 ↗BPC-157/TB-500 Blend · 99.10% HPLC2026-09-22
- RV-24-0038-1 ↗BPC-157/TB-500 Blend · 99.10% HPLC2026-09-16
References
- Chang CH, Tsai WC, Lin MS, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. Journal of applied physiology (Bethesda, Md. : 1985). 2011.
- Esposito S, Deventer K, Goeman J, et al. 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. Drug testing and analysis. 2012.
- Delcourt V, Garcia P, Chabot B, et al. TB500/TB1000 and SGF1000: A scientific approach for a better understanding of misbranded and adulterated drugs. Drug testing and analysis. 2023.
- Hsieh MJ, Liu HT, Wang CN, et al. Therapeutic potential of pro-angiogenic BPC157 is associated with VEGFR2 activation and up-regulation. Journal of molecular medicine (Berlin, Germany). 2017.
- Shah R, Reyes-Gordillo K, Rojkind M Thymosin β4 inhibits PDGF-BB induced activation, proliferation, and migration of human hepatic stellate cells via its actin-binding domain. Expert opinion on biological therapy. 2018.
- Cox HD, Miller GD, Eichner D Detection and in vitro metabolism of the confiscated peptides BPC 157 and MGF R23H. Drug testing and analysis. 2017.
- Staresinic M, Sebecic B, Patrlj L, et al. Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 2003.
- Zoubek RE, Hannappel E Influence of the N terminus and the actin-binding motif of thymosin beta4 on its interaction with G-actin. Annals of the New York Academy of Sciences. 2007.
- Judák P, Van Eenoo P, Deventer K Adsorption effects of the doping relevant peptides Insulin Lispro, Synachten, TB-500 and GHRP 5. Analytical biochemistry. 2017.
Publication records fetched from PubMed on 2026-09-20. Profile text reviewed 2026-09-20.