BPC-157, TB-500, KPV, GHK-Cu: Mechanisms Across the Tissue-Repair Cascade

Reviewed and corrected August 27, 2026 · Artemis Labs

Four compounds, four separate literatures. BPC-157 is a 15-amino-acid peptide copying part of a protein found in human gastric juice. TB-500 is a synthetic seven-residue peptide, Ac-LKKTETQ, matching residues 17–23 of thymosin β4. KPV is the C-terminal tripeptide of α-MSH. GHK-Cu is a copper-bound tripeptide whose human evidence is topical and cosmetic. Their reported mechanisms address different steps of tissue repair, which is why they are discussed together. No published study has tested any combination of them — not in cells, not in animals, not in people.

Research highlights

Corrections to an earlier version of this page. An earlier version stated that GHK-Cu influences “4,000+ genes”, that published research documents synergistic outcomes for these compounds, and that two of them deliver “approximately 70% of the full efficacy” of all four. None of those statements had a source. All three have been removed, and no substitute figures exist.
The gene-expression claim, traced. The “4,000 genes / resetting DNA” wording originates in a review series written by staff of a company that sells the compound — the affiliation on that paper reads “Skin Biology, Research & Development Department… Bellevue, WA” (PMID 26236730). The only independent primary work is a computational screen that identified 127 genes (PMID 22937864), and it studied the copper-free tripeptide.
An earlier version also carried a week-by-week outcome timeline. There is no human trial of any of these four compounds in tissue repair from which such a timeline could be drawn. It has been deleted rather than rewritten.
Where the human evidence actually stands. BPC-157: no published Phase II or Phase III efficacy trial for any use. TB-500: no published human trial of the fragment at all. KPV: entirely preclinical. GHK-Cu: two human randomized trials in 34 years, both topical, both negative on every objective endpoint, and zero controlled human data for any non-topical route.

Why are these four discussed together?

Tissue repair is not one event. Published descriptions of wound and connective-tissue healing divide it into overlapping stages — an early inflammatory response, a proliferative stage in which cells migrate into the injury space and new blood vessels form, and a longer remodeling stage in which collagen is cross-linked and reorganised. The stages overlap rather than following one another cleanly, and their durations differ by tissue.

The reason these four compounds get named in the same sentence is that their reported mechanisms sit at different points of that sequence. BPC-157’s animal literature clusters around growth-factor and nitric-oxide signalling. The region TB-500 copies is described as an actin-binding domain involved in cell movement. KPV’s preclinical work is about damping inflammatory signalling. GHK-Cu’s work is largely about collagen and extracellular matrix.

That is a rationale for studying them together. It is not a finding. The distinction matters, because the second reading is the one that gets sold, and there is no experiment behind it.

What each compound is

Compound	Identity	Human evidence status
BPC-157	15 amino acids, GEPPPGKPADDAGLV · 1,419.54 g/mol · CAS 137525-51-0 · PubChem CID 9941957. A partial sequence of a protein found in human gastric juice.	No published Phase II or Phase III efficacy trial for any use. Its FDA compounding status is unsettled and should not be described as resolved.
TB-500	7 amino acids, acetylated: Ac-LKKTETQ · 889.0 g/mol · CAS 885340-08-9 · PubChem CID 62707662. Matches residues 17–23 of thymosin β4, a 43-residue protein of about 4,963 Da.	No published human trial of the fragment. Human trials exist only for the full-length parent protein.
KPV	3 amino acids, Lys-Pro-Val — residues 11–13 of α-melanocyte-stimulating hormone (α-MSH).	Entirely preclinical: no published human efficacy, pharmacokinetic, ADME or long-term safety data.
GHK-Cu	Glycyl-L-histidyl-L-lysine coordinating a copper(II) ion · 402.92 g/mol · CAS 89030-95-5 · PubChem CID 71587328. The copper-free tripeptide GHK is a different molecule (340.38 g/mol, CAS 49557-75-7, CID 73587).	Two randomized human trials, both topical, both negative on their objective endpoints. No controlled human data for any non-topical route.

The GHK / GHK-Cu split is worth pausing on, because the primary databases blur it. Six PubChem records answer to the name “GHK-Cu”, and one of them is the copper-free peptide. Any molecular weight or CAS number published without its PubChem CID beside it is ambiguous.

What has BPC-157 actually been studied for?

Every item below is a bounded report from a named model. None of it is a human efficacy result.

Growth-factor upregulation. Increases in VEGF (vascular endothelial growth factor, the main signal for new blood-vessel formation), EGF (epidermal growth factor) and HGF (hepatocyte growth factor) were reported in an alkali-burn model (Huang 2015), a rectovaginal-fistula model in rats (Baric 2016), and an ocular review (Sikiric 2023).
Nitric-oxide system involvement. A rat study linked BPC-157 to the nitric-oxide pathway using L-NAME and L-arginine co-treatment (Amam 2018). In 2026, a tissue-bath study reported concentration-dependent, endothelium-dependent, nitric-oxide-mediated relaxation of human internal mammary artery rings left over from bypass surgery (PMID 42123221). That is human tissue in a dish, not a clinical trial.
Cell outgrowth and migration in culture. Faster tendon-cell outgrowth, survival and migration were reported through FAK–paxillin signalling (Chang 2011), with increased growth-hormone-receptor expression in tendon fibroblasts — the cells that build connective tissue — in a later paper (Chang 2014).
Connective-tissue healing in animals. Improved ligament healing was reported in a rat knee-ligament transection model (Cerovecki 2010), the foundational orthopaedic study for this compound.
Cytoprotection and gut models. A synthesis paper describes vascular recruitment and gastrointestinal healing across cytoprotection models (Sikiric 2018).

A structural caveat travels with all of it: BPC-157 has no single defined receptor, no canonical binding assay separating a positive from a null response, and reported effect sizes vary substantially with model, dose, route and species.

What has TB-500 actually been studied for?

The honest answer is short, and most comparisons quietly substitute the parent protein’s research for the fragment’s.

The fragment’s own literature is four papers. A 2003 study reported that “the actin-binding domain of thymosin beta 4 duplicated in a seven-amino acid synthetic peptide, LKKTETQ, was able to promote repair in the aged animals comparable to that observed with the parent molecule” — aged mice, no dose stated in the abstract (Philp 2003). A 2026 paper gave TB500 to cells and to transgenic Alzheimer’s-model mice and reported improved maze and object-recognition performance, while stating its own negative result plainly: hippocampal amyloid burden was unchanged (Ou 2026). A 2025 paper delivered the fragment in a hydrogel to an alkali-burned mouse and rabbit eye and called it “the first ocular application of TB500” (Lu 2025). The fourth is a doping-control detection assay in horses, not an efficacy study (Ho 2012).

The actin claim, at the strength the source supports. A review describes “LKKTETQ, the central actin-binding domain (aa 17-23) plus 1 additional amino acid (Q)” as promoting “angiogenesis, wound healing, and cell migration” in the models it surveyed (Sosne 2010). That supports calling LKKTETQ an actin-binding region. It does not support the stronger cytoskeletal mechanism wording that circulates on vendor pages and that an earlier version of this page repeated.

And one finding that complicates all of it. A 2024 pharmacology paper opens: “The biological effects of TB-500, however, have not been documented.” It tracked TB-500 breakdown in human serum, in enzyme systems and in urine from treated rats, and concluded that “the previously reported wound-healing activity of TB-500 in literature may be due to its metabolite Ac-LKKTE rather than the parent form” (Rahaman 2024). Read plainly: it is not settled that the seven-residue molecule sold as TB-500 is the active species at all.

A fuller treatment of the fragment-versus-parent problem is in our BPC-157 and TB-500 comparison and in what the TB-500 human trial record contains.

What has KPV actually been studied for?

KPV is the shortest of the four: three amino acids taken from the tail end of α-MSH. The wording of its mechanism matters, because the obvious inference is wrong.

Although KPV is derived from α-MSH, its reported anti-inflammatory action operates largely independently of melanocortin receptors. Published work describes the peptide entering cells and inhibiting nuclear translocation of NF-κB — the transcription factor that drives pro-inflammatory gene expression (PMID 18061177). A separate study reported that KPV did not act through melanocortin receptors in a crystal-induced peritonitis model (PMID 12750433). “Derived from α-MSH” is accurate for origin; attributing its action to the melanocortin pathway is not.

Its published models are colitis, dermatitis and arthritis, with more recent work on delivery systems for inflammatory bowel disease (Jeong 2025; Li 2024) and a 2026 hepatic-lipid finding in cultured HepG2 cells (Lee 2026). None of it is human. Our BPC-157 and KPV comparison sets the two records side by side.

What has GHK-Cu actually been studied for?

GHK-Cu has the largest popular literature of the four and the smallest controlled one. Two facts govern how it can honestly be described.

First, nearly all of its human evidence is topical and cosmetic. PubChem’s own drug-indication field for both the peptide and the copper complex reads, in full: “Commonly used in cosmetic products for the skin and hair.” That is the primary database’s description of the compound.

Second, the two randomized human trials that exist were negative. A 1992 trial at the University of Texas Medical Branch compared a 0.4% tripeptide-copper-complex cream against silver sulfadiazine and an inert vehicle placebo in venous stasis ulcers, randomized and evaluator-blinded, with 86 evaluable patients. Its result, verbatim: silver sulfadiazine “proved to statistically reduce the ulcer size compared with a biologically active tripeptide copper complex 0.4% cream formulation or the placebo. There was no difference between the latter two treatments” (PMID 1495150). The copper peptide was indistinguishable from placebo, and was beaten by a cheap generic in the same trial. A 2006 trial of a topical copper-tripeptide product on carbon-dioxide-laser-resurfaced skin, 13 participants, reported “no statistically significant differences between groups” and that “objective evaluation found no significant improvement in wrinkles or overall skin quality” (PMID 16847171). The only positive readout there was a self-reported questionnaire.

A third record carries PubMed’s randomized-controlled-trial tag, which is how the frequently repeated “three trials” figure arises. It is a study in 18 rabbits (PMID 17083573).

The gene-expression story, at its actual provenance. The claim that GHK-Cu regulates thousands of genes and “resets DNA” appears in a review series whose authors all list the same affiliation — a company that sells the compound, in Bellevue, Washington (PMID 26236730). The independent primary work underneath it is a single 2012 paper from Boston University and the University of British Columbia. It profiled 64 lung-tissue samples, identified 127 genes associated with emphysema severity, and used a computational screen of the Connectivity Map to nominate GHK — the copper-free tripeptide — as a compound predicted to reverse that signature; cultured human fibroblasts treated with GHK then reproduced TGF-β-like expression patterns (PMID 22937864). There is no animal work and no human dosing in that paper, and the authors call for further study themselves. Our pages publish no gene count as an established fact, because the number that circulates has no independent source.

What else has been reported. Recent primary work is preclinical: lifespan extension in the nematode C. elegans through mitochondrial and DAF-16/SKN-1 pathways (Wen 2026), and reduced neutrophil and macrophage migration with suppressed inflammatory markers in zebrafish larvae (Hu 2026). A 2026 PRISMA systematic review searching for GHK-Cu as a standalone intervention found 20 studies — 18 preclinical, 2 randomized trials — arriving at the same count by an independent method (PMID 42619529).

Six of the eight human application studies in this literature, including every hair and scalp study and every positive cosmetic result, used multi-ingredient formulations in which GHK-Cu’s individual contribution cannot be separated from the rest of the product. The two studies with an attributable effect are the two randomized trials, and both were null. Our BPC-157 and GHK-Cu comparison goes further into that record.

Has anyone studied these compounds together?

No. There is no published study of any combination of BPC-157, TB-500, KPV and GHK-Cu — not two of them, not four. The literature passes behind this page found none.

An earlier version of this page attached a percentage to the idea, suggesting that two of the compounds delivered roughly 70% of what all four would. That figure had no source and read as an efficacy claim. It has been removed, and no substitute figure exists, because no combination study exists to produce one. The same applies to the pre-formulated blends: GLOW (GHK-Cu 50 mg + BPC-157 10 mg + TB-500 10 mg) and KLOW (GLOW plus KPV 10 mg) are formulations, and no published study has tested either of them. What differs between them is composition, not demonstrated performance — a point our page on single compounds compared with blends takes up directly.

What the research does not show

No human efficacy trial exists for any of the four in tissue repair. BPC-157 has no published Phase II or Phase III trial for any use. TB-500 has no human trial of the fragment at all. KPV’s record is entirely preclinical. GHK-Cu’s two human trials were topical and negative.
An independent animal study found GHK-Cu made healing slower, not faster. In guinea-pig dorsal skin, tripeptide-copper complexes produced “a slower reorganization of the skin and a delayed activation of fibroblasts” (PMID 8836453). In the same paper’s cell cultures, the compounds “decreased cell reproduction” while increasing collagen expression.
A GHK-Cu benefit that did not survive withdrawal. In a rat anterior-cruciate-ligament reconstruction model, a difference in knee laxity at 6 weeks had disappeared by 12 weeks, with no significant difference in ultimate load, gait or histology; the word “transiently” is in the paper’s own title (PMID 25731775).
Nulls in bone. GHK-Cu coating “had no effect” on osteoblast spreading and “slightly inhibited” markers of osteoblast phenotype (PMID 8747089).
The GHK-Cu concentration–response reported in culture is biphasic. One study reported maximal stimulation of collagen synthesis at nanomolar concentrations, after which “the rate of synthesis returned progressively to that of control cultures” (PMID 1522753). More was not better in that experiment.
Counter-evidence on thymosin β4. In an irritable-bowel-syndrome model, thymosin β4 released by mast cells reduced tight-junction proteins and impaired intestinal barrier integrity in rats and mice, with elevated thymosin β4 measured in the colonic mucus of patients (Sun 2025). That study examined endogenous full-length thymosin β4, not the TB-500 fragment, and had no human dosing arm. We surface it because honest disclosure is the standard we hold ourselves to, not because it transfers directly.
Product-content risk is documented. A drug-testing paper on TB500/TB1000 products concluded: “We confirm that the content of TB500/TB1000 products is not systematically consistent with it’s former descriptions” (Delcourt 2023). That is a published finding about marketed material in this category, and it applies to the whole category.
Sport prohibition. The WADA 2026 Prohibited List names, under section S2.3, “Thymosin-β4 and its derivatives e.g. TB-500”; S2 substances are prohibited at all times. BPC-157 falls under the same section (WADA Prohibited List).

Common questions

Is there evidence that these four work better in combination than separately?

No. No published study has tested any combination of them, so there is no result to report in either direction. The pairing rationale is that their reported mechanisms address different steps of repair. That is a reason to study a combination, not a finding from one.

Which of the four has the most published research behind it?

BPC-157, by a wide margin among primary animal studies — tendon, ligament, muscle, gut, blood vessel, brain and eye models. GHK-Cu has the largest total publication count but the smallest controlled record, and much of what looks like GHK-Cu research studies the copper-free peptide. TB-500’s own literature is four papers. KPV’s is preclinical inflammation work.

Why can’t the GHK-Cu skin research be applied to a research vial?

Because of formulation and route. Every human study of GHK-Cu applied it to skin, most of them as one ingredient in a multi-ingredient cosmetic product. There is no controlled human data for any non-topical route — six separate search formulations returned nothing, and the only systemic-route record indexed is a study in dogs. A topical cosmetic result does not carry across to a different form of the compound.

How does KPV differ from a general anti-inflammatory?

Published work describes KPV acting inside the cell on NF-κB nuclear translocation rather than through melanocortin receptors (PMID 18061177). Whether that specificity carries any advantage in a living human is unknown, because no human study of KPV has been published.

Is TB-500 the same as thymosin β4?

No. TB-500 is a synthetic, acetylated seven-residue peptide matching residues 17–23 of thymosin β4. Thymosin β4 is a 43-residue protein roughly five and a half times heavier. Reading a thymosin β4 study as a TB-500 study is the most common error in this subject.

How is a compound’s identity confirmed on paper?

By matching the sequence and molecular weight against the primary databases. BPC-157 should read GEPPPGKPADDAGLV and 1,419.54 g/mol; TB-500 should read Ac-LKKTETQ and 889.0 g/mol, where 847.0 g/mol would indicate the uncapped peptide, a different compound; GHK-Cu should carry PubChem CID 71587328 and 402.92 g/mol, not the copper-free peptide’s 340.38. For a multi-component blend, a single combined chromatogram cannot resolve the individual components. Our HPLC explainer covers how such a chromatogram is read.

Compound records: BPC-157 · TB-500 · KPV · GHK-Cu

References

Huang T, et al. BPC-157 in alkali-burn wound healing. DOI 10.2147/DDDT.S82030
Baric M, et al. BPC-157 in rectovaginal fistula repair in rats. DOI 10.1016/j.lfs.2016.02.029
Sikiric P, et al. BPC-157 in ocular animal models (review). DOI 10.3390/ph16071052
Amam I, et al. BPC-157 and the nitric-oxide system in a rat venous-occlusion model. DOI 10.3748/wjg.v24.i47.5366
Yildirim S, et al. BPC-157 and endothelium-dependent relaxation of human internal mammary artery ex vivo. PMID 42123221
Chang CH, et al. BPC-157 and tendon fibroblast outgrowth via FAK–paxillin. DOI 10.1152/japplphysiol.00945.2010
Chang CH, et al. BPC-157 and growth-hormone-receptor expression in tendon fibroblasts. DOI 10.3390/molecules191119066
Cerovecki T, et al. BPC-157 in a rat medial collateral ligament transection model. DOI 10.1002/jor.21107
Sikiric P, et al. BPC-157 cytoprotection and gastrointestinal healing (review). DOI 10.2174/1381612824666180608101119
Philp D, et al. Thymosin β4 and a synthetic peptide containing its actin-binding domain promote dermal wound repair in aged mice. PMID 12581423
Sosne G, et al. Thymosin beta 4: a potential novel therapeutic agent for ocular disorders (review). PMID 20179146
Ho ENM, et al. Detection of TB-500 (N-acetylated LKKTETQ) in equine plasma and urine. PMID 23084823
Ou Z, et al. Thymosin β4-derived peptides TB500 and Ac-SDKP in Alzheimer’s disease models. PMID 41443105
Lu Y, et al. Enzyme-triggered hydrogel delivery of TB500 in an alkali-burn ocular model. PMID 41359360
Rahaman A, et al. Metabolism of TB-500 in human serum, enzyme systems and rat urine. PMID 38382158
Sun YS, et al. Thymosin β4 released by mast cells impairs the intestinal epithelial barrier via IL22RA1/JAK1/STAT3 in IBS. PMID 41278163
Delcourt V, et al. TB500/TB1000 and SGF1000: misbranded and adulterated drugs. PMID 36482504
KPV and NF-κB nuclear translocation. PMID 18061177
KPV action independent of melanocortin receptors in crystal-induced peritonitis. PMID 12750433
Jeong J, et al. KPV delivery research in inflammatory bowel disease models. PMID 40030207
Li Y, et al. KPV delivery research in inflammatory bowel disease models. PMID 38289234
Lee S, et al. KPV and hepatic lipid handling in HepG2 cells. PMID 42064835
A prospective randomized evaluator-blinded trial of two potential wound healing agents for venous stasis ulcers. J Vasc Surg, 1992. PMID 1495150
Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg, 2006. PMID 16847171
Copper tripeptide complex in a rabbit wound model. Vet Dermatol, 2006. PMID 17083573
GHK-Cu as a standalone intervention: PRISMA systematic review, 2026. PMID 42619529
A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK. Genome Med, 2012. PMID 22937864 · DOI 10.1186/gm367
GHK peptide as a modulator of cellular pathways in skin (vendor-affiliated review — cited here for provenance only). Biomed Res Int, 2015. PMID 26236730
Wen Y, et al. GHK-Cu and lifespan in C. elegans. PMID 42084774
Hu J, et al. GHK-Cu in zebrafish-larvae inflammation models. Eur J Pharmacol, 2026. PMID 41997403
Effect of tripeptide-copper complexes on skin wound healing and cultured fibroblasts (guinea pig). Arch Int Pharmacodyn Ther, 1995. PMID 8836453
Tripeptide-copper complex GHK-Cu(II) transiently improved healing outcome in a rat ACL reconstruction model. J Orthop Res, 2015. PMID 25731775
Effects of GHK-Cu on osteoblastic cell spreading, attachment and phenotype. Cell Mol Biol, 1995. PMID 8747089
Biphasic concentration–response of GHK-Cu on collagen synthesis in culture. PMID 1522753
World Anti-Doping Agency, 2026 Prohibited List, section S2.3. wada-ama.org/en/prohibited-list

Methodology: this page draws only on the verified Artemis facts sheets for BPC-157, thymosin β4 / TB-500 and GHK-Cu, each built by re-reading the cited abstracts directly through NCBI E-utilities and confirming compound identity against PubChem. Corrections applied and links re-verified August 27, 2026. Claims that could not be traced to a cited abstract were removed rather than rewritten.

All compounds sold by Artemis Labs are for laboratory research use only. Nothing on this page is medical advice, and no statement has been evaluated by the FDA.