BPC-157 vs TB-500: two repair-literature peptides compared

The short version

BPC-157 and TB-500 are the two peptides most often mentioned together in the research-chemical market, and they are often sold as a blend, but they have almost nothing in common chemically. BPC-157 is a 15-residue sequence described as a fragment of a protein found in gastric juice; TB-500 is a seven-residue, N-acetylated fragment of thymosin β4, the most abundant actin-sequestering protein in mammalian cells. Neither has a defined receptor. The literature on BPC-157 is large but comes overwhelmingly from a single research group and consists almost entirely of rodent studies; the literature on TB-500 as a fragment is small, but it sits inside a much larger and more independent literature on the parent protein, which has reached phase 2 and phase 3 clinical trials. Neither is a licensed medicine anywhere; both are on the WADA Prohibited List. For a laboratory the two are different tools for different questions, and the reasons to pair them are more commercial than scientific.

Both compounds are supplied by BuyUK Peptides as research chemicals for in-vitro laboratory use only. Nothing on this page is guidance for any other use.

Origin and sequence

BPC-157 was described in the early 1990s by Sikiric and colleagues in Zagreb as a stable fragment of a larger gastric protein, and the name reflects the claim that it protects tissue [1]. The sequence is unusual: a run of three prolines near the N-terminus, no aromatic residues, no cysteine, and a high proportion of glycine, proline and aspartate. Those features make it resistant to acid and to many proteases, which is the basis for the "stable gastric pentadecapeptide" description in the group's papers.

TB-500 is defined by a different kind of reasoning. Thymosin β4 is a well-characterised protein; its principal actin-binding site was mapped in 1996 to a hexapeptide motif, LKKTET, at residues 17 to 22 [2], and later work showed that a synthetic peptide covering residues 17 to 23 reproduced the angiogenic and migration-promoting activity of the full protein in endothelial assays [3]. TB-500 is that peptide with the native acetylation carried over. It is a fragment chosen because mapping studies put the relevant activity there, which is a stronger rationale than BPC-157's, where the relationship between the 15-residue fragment and any parent protein has never been fully established.

Mechanism as the literature describes it

Neither peptide has a receptor in the pharmacological sense, and this is the first thing to understand about both.

For BPC-157 the Sikiric group proposes a set of overlapping effects: modulation of the nitric-oxide system, upregulation of growth-factor receptors including VEGFR2, promotion of blood-vessel recruitment around injured tissue, and interaction with the dopamine and serotonin systems in the brain [1, 4]. The VEGFR2 work by Hsieh and colleagues is the most mechanistically specific paper, reporting that BPC-157 increased VEGFR2 expression and activated the Akt–eNOS pathway in endothelial cells and promoted vessel formation in a rat model [5]. The tendon-healing paper by Chang and colleagues is the most cited in-vitro study, reporting increased tendon-fibroblast outgrowth, survival and migration with activation of FAK–paxillin signalling [6]. What is missing is a binding partner: no paper identifies the molecule that BPC-157 binds to, and so the mechanism remains a description of downstream effects.

For TB-500 the mechanism is inherited from the parent protein and is, at least at the level of the motif, better understood. Thymosin β4 sequesters monomeric G-actin, holding the cell's actin reserve, and through that and through other interactions it influences cell migration, angiogenesis and wound repair [7, 8]. The LKKTET motif is the part of the protein that contacts actin, and the 17–23 peptide inhibits actin polymerisation and reproduces several of the full protein's effects in cell systems [3]. Whether the fragment also reproduces the actions of Tβ4 that depend on its other segments, such as the anti-inflammatory N-terminal tetrapeptide Ac-SDKP, is a question the mapping literature answers in the negative: those activities live elsewhere in the sequence [9].

The shape of the evidence

This is where the two differ most, and a researcher choosing between them should look at it closely.

BPC-157. Several hundred papers, the great majority from one group and its collaborators, almost all in rats, and covering an exceptionally wide range of models: gastric and intestinal lesions, tendon and ligament transection, muscle injury, bone healing, vascular occlusion, and various centrally mediated behaviours [1, 4, 6]. A 2019 review of the musculoskeletal work and a 2025 literature and patent review summarise it [10, 11]. The width is the striking feature and also the reason for caution: a single compound reported to act on so many systems, with no identified binding partner, from one laboratory, is a pattern that calls for independent replication, and there is very little of it. The human evidence is limited to a small uncontrolled case series [12]. A phase 1 trial registered by a commercial sponsor is not published.

TB-500 and thymosin β4. The fragment's own record is small: the endothelial and angiogenesis assays of Philp and colleagues [3], a hepatic stellate-cell study that localised an anti-fibrotic effect to the 17–23 region [13], and a chemical characterisation of the seized product for anti-doping purposes [14]. The parent protein, by contrast, has an independent literature from many groups, including the cardiac repair work by Bock-Marquette and colleagues in Nature [8], dermal wound-healing studies [15], and randomised phase 2 trials of a thymosin β4 ophthalmic solution for dry eye and neurotrophic keratopathy [16]. A researcher working with TB-500 is working with a fragment whose relationship to a well-studied protein is defined, which is a different position from working with BPC-157.

Regulatory and anti-doping status in the UK

Neither peptide is a licensed medicine in the UK or anywhere else, and neither is a controlled drug under the Misuse of Drugs Act. Both are supplied here as chemicals for in-vitro laboratory use under the Terms of Sale, not as medicines, and the UK rules on research compounds set out the position in detail.

Both are prohibited in sport, but under different sections. BPC-157 was added to the WADA Prohibited List from 1 January 2022 under S0, non-approved substances [17]. TB-500 is named explicitly under S2.3, growth factors and growth factor modulators, as a derivative of thymosin β4 [18]. Both classes are prohibited at all times.

Handling at the bench

The two handle alike in most respects and differ in one. Both are supplied lyophilised, keep for years at −20 °C and for many months at 2 to 8 °C sealed, and should reach room temperature before the vial is opened. Both dissolve readily in water or bacteriostatic water, neither has a lipid tail, so neither adsorbs to plastics the way the incretin peptides do, and neither has a cysteine, so disulphide scrambling is not a concern. Neither has an aromatic residue, which matters analytically: UV detection must be at 214 or 220 nm, and a certificate quoting purity at 280 nm is meaningless for either peptide.

The difference is stability in solution. BPC-157 is unusually robust; its proline-rich sequence resists acid and most proteases, and solutions keep well at 2 to 8 °C. TB-500 carries two lysines and a glutamine and is more exposed to deamidation and to microbial degradation; it should be reconstituted in bacteriostatic water, kept cold, and used within a few weeks. The storage and stability guide covers both.

What to look for on the certificate

For both, RP-HPLC purity should be 98 per cent or above with a single dominant peak, and the LC-MS identity line should match the expected mass: about 1,419.6 Da for BPC-157, where the doubly charged ion at m/z 710.8 is what most laboratories see, and 889.0 Da for TB-500, which appears as the singly charged ion at m/z 889.5 or the doubly charged at 445.3. The TB-500 mass is the item to insist on, because it distinguishes the fragment from full-length thymosin β4 at 4,963 Da, and some suppliers blur the two. For BPC-157 the common impurities are deletion sequences missing a proline; for TB-500 they are the des-acetyl peptide and deletions of a lysine or threonine. Net peptide content is worth having for both, since short peptides can carry a considerable weight of counter-ion and water. The guide to reading a certificate walks through a full report.

On the blend

BPC-157 and TB-500 are often sold combined, and we list a BPC-157 and TB-500 blend because researchers ask for it. The scientific case for the combination is thin: there is no published study of the two together, and the two peptides have no shared mechanism that would predict an interaction. A blend is a convenience for a researcher who intends to study the pair in the same system; a laboratory asking a question about either compound on its own should buy it on its own, since a blend's certificate can only report the two peptides' combined purity and cannot characterise each as fully as the single-compound certificates do.

Which to choose

For a question about actin dynamics, endothelial migration or angiogenesis in a defined cell system, TB-500 is the better-characterised tool, with the parent protein as a positive control and a mapped motif as the rationale. For a question that starts from the BPC-157 literature itself, for example an attempt to reproduce one of the tendon-fibroblast or endothelial findings independently, BPC-157 is the only choice, and independent reproduction of that literature would be a contribution in its own right. Full accounts with references are in the monographs: BPC-157 and TB-500.

References

1. Sikiric P, Seiwerth S, Rucman R, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Current Pharmaceutical Design. 2011;17(16):1612–1632. doi:10.2174/138161211796196954.
2. Van Troys M, Dewitte D, Goethals M, Carlier MF, Vandekerckhove J, Ampe C. The actin binding site of thymosin β4 mapped by mutational analysis. EMBO Journal. 1996;15(2):201–210. doi:10.1002/j.1460-2075.1996.tb00350.x.
3. Philp D, Huff T, Gho YS, Hannappel E, Kleinman HK. The actin binding site on thymosin β4 promotes angiogenesis. FASEB Journal. 2003;17(14):2103–2105. doi:10.1096/fj.03-0121fje.
4. Sikiric P, Rucman R, Turkovic B, et al. Novel cytoprotective mediator, stable gastric pentadecapeptide BPC 157. Vascular recruitment and gastrointestinal tract healing. Current Pharmaceutical Design. 2018;24(18):1990–2001. doi:10.2174/1381612824666180608101119.
5. 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. 2017;95(3):323–333. doi:10.1007/s00109-016-1488-y.
6. Chang CH, Tsai WC, Lin MS, Hsu YH, Pang JHS. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. Journal of Applied Physiology. 2011;110(3):774–780. doi:10.1152/japplphysiol.00945.2010.
7. Goldstein AL, Hannappel E, Kleinman HK. Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends in Molecular Medicine. 2005;11(9):421–429. doi:10.1016/j.molmed.2005.07.004.
8. Bock-Marquette I, Saxena A, White MD, DiMaio JM, Srivastava D. Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466–472. doi:10.1038/nature03000.
9. Sosne G, Qiu P, Goldstein AL, Wheater M. Biological activities of thymosin β4 defined by active sites in short peptide sequences. FASEB Journal. 2010;24(7):2144–2151. doi:10.1096/fj.09-142307.
10. Gwyer D, Wragg NM, Wilson SL. Gastric pentadecapeptide body protection compound BPC 157 and its role in accelerating musculoskeletal soft tissue healing. Cell and Tissue Research. 2019;377(2):153–159. doi:10.1007/s00441-019-03016-8.
11. Józwiak M, Bauer M, Kamysz W, Kleczkowska P. Multifunctionality and possible medical application of the BPC 157 peptide—literature and patent review. Pharmaceuticals. 2025;18(2):185. doi:10.3390/ph18020185.
12. Lee E, Padgett B. Intra-articular injection of BPC 157 for multiple types of knee pain. Alternative Therapies in Health and Medicine. 2021;27(4):8–13. PMID 34324435.
13. 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;18(sup1):177–184. doi:10.1080/14712598.2018.1478962.
14. Esposito S, Deventer K, Goeman J, Van der Eycken J, Van Eenoo P. 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;4(9):733–738. doi:10.1002/dta.1402.
15. Malinda KM, Sidhu GS, Mani H, et al. Thymosin β4 accelerates wound healing. Journal of Investigative Dermatology. 1999;113(3):364–368. doi:10.1046/j.1523-1747.1999.00708.x.
16. Sosne G, Dunn SP, Kim C. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea. 2015;34(5):491–496. doi:10.1097/ICO.0000000000000379.
17. UK Anti-Doping. Major changes to the 2022 Prohibited List: what you need to know. Published 2021. network.ukad.org.uk.
18. World Anti-Doping Agency. The Prohibited List 2026. Section S2.3, Growth factors and growth factor modulators. In force 1 January 2026. wada-ama.org.

This monograph summarises the published literature for laboratory researchers. It is not medical advice, and nothing on this site is for human or veterinary use.