Search any peptide forum and BPC-157, TB-500, KPV and GHK-Cu turn up in the same breath, usually filed under some version of “the healing peptides.” That grouping comes from where they show up in the research literature, not from any shared chemistry. They are four structurally unrelated molecules: a 15-amino-acid synthetic peptide, a 43-amino-acid protein (or a seven-residue fragment of it, depending on what is really in the vial), a three-amino-acid fragment of a hormone, and a copper complex. None of them is an FDA-approved drug. All four are sold for laboratory research use only.
The reason it is worth comparing them on one page is not to pick a winner — we don’t rank compounds and we make no usage claims. It’s that each one fails verification in a different place. Two of the four are routinely sold under an identifier that describes a different molecule from the one in the vial, which means a Certificate of Analysis can be internally consistent, professionally formatted, and still not prove you have what the label says.
The four at a glance
| Compound | What the molecule is | Size | Where it appears in the literature |
|---|---|---|---|
| BPC-157 | Synthetic peptide; sequence corresponds to a fragment of a “body protection compound” identified in human gastric juice | 15 amino acids · C62H98N16O22 · 1419.55 g/mol | Preclinical tissue-repair and wound-healing work; gastrointestinal-protection research; tendon, ligament and muscle animal models |
| TB-500 | Market name for material derived from thymosin beta-4, a naturally occurring protein | 43 amino acids full-length · 4963 g/mol — but often sold as the shorter LKKTETQ fragment | Preclinical angiogenesis and blood-vessel formation; tissue-repair cell and animal studies; cardiac and muscle protection research |
| KPV | Naturally occurring tripeptide (Lys-Pro-Val); the C-terminal fragment of alpha-MSH | 3 amino acids · C16H30N4O4 · 342.43 g/mol | Melanocortin peptide chemistry; inflammation and NF-κB signalling cell models; epithelial and gastrointestinal in-vitro research |
| GHK-Cu | Copper-binding tripeptide (Gly-His-Lys) complexed with copper; found naturally in blood plasma | Copper tripeptide · C14H22CuN6O4 · 401.91 g/mol | Skin-remodelling and wound-healing cell and animal studies; copper-binding and tissue-repair biochemistry; collagen and gene-expression preclinical work |
Research areas describe where a compound appears in published laboratory work — largely cell and animal studies. Listing one is not a health claim and does not indicate any effect in people.
BPC-157: the most-sold, the most-counterfeited
BPC-157 is a pentadecapeptide — fifteen amino acids, sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. Its sequence corresponds to a fragment of a protein originally identified in human gastric juice, which is where the “body protection compound” name comes from. In the literature it shows up mostly in preclinical tissue-repair, gastrointestinal-protection, and tendon and ligament animal work.
Its regulatory position is the one people most often get wrong. The FDA placed BPC-157 in Category 2 of its 503A bulk-substances list in 2023, and in April 2026 removed it from that list pending an advisory-committee review. Removal from a risk list is not approval. As of 2026 BPC-157 remains not approved for human use, and any vendor presenting the 2026 delisting as an FDA green light is telling you something about their compliance posture, not about the compound.
Because BPC-157 is the highest-volume compound in this group, it is also the one where fakes, underfills and recycled COAs concentrate. It is short enough to synthesise cheaply and short enough to fake convincingly on paper. The verification burden is ordinary but non-negotiable: a batch-specific COA, HPLC purity, and a mass-spec identity result matching 1419.55 g/mol. We wrote the full sourcing routine up separately in how to choose a BPC-157 vendor, and the current vendor-by-vendor price spread sits on the BPC-157 price page.
TB-500: the identity trap
This is the one that catches careful buyers. TB-500 is a market name, not a precise chemical one. The CAS number almost universally filed against it — 77591-33-4 — identifies full-length thymosin beta-4: 43 amino acids, molecular weight around 4963 g/mol. A large share of the product actually sold as TB-500 is the shorter LKKTETQ active fragment, which is a completely different molecule with a completely different mass.
The FDA’s own listing is instructive here: it names “Thymosin beta-4, fragment (LKKTETQ), also known as TB-500” among bulk drug substances that may present significant safety risks — Category 2, page content current as of 22 April 2026. Even the regulator treats the fragment and the protein as things that need naming separately.
So the single question to ask a TB-500 vendor is: which molecule is in this vial, and does the COA state its expected mass? A vendor who can answer that in one sentence is a different class of operator from one who replies “it’s TB-500.” Full details and current listings are on the TB-500 page, and the purity-versus-identity distinction behind all of this is explained in HPLC vs mass spec.
KPV: three amino acids, and a regulatory footnote worth reading
KPV is the smallest compound here by a wide margin — a tripeptide of lysine, proline and valine, 342.43 g/mol, corresponding to the C-terminal fragment of alpha-melanocyte-stimulating hormone (alpha-MSH 11-13). In laboratory work it appears in melanocortin peptide chemistry and in cell models of inflammatory signalling, including NF-κB pathway and epithelial or gastrointestinal in-vitro research.
Its regulatory history has a detail most listings omit. KPV was nominated for the FDA’s compounding bulk-substances list and placed in Category 2 — but the nomination was subsequently withdrawn by the nominator, with the FDA noting a lack of human exposure data. That is not a clearance and not a rejection; it is an absence of evaluation, and it is worth knowing before you read a vendor page that describes KPV as “FDA-reviewed.”
On the sourcing side, KPV’s small size cuts both ways. Short peptides are cheap and straightforward to synthesise, so genuine material is relatively easy to make — but a 342 g/mol tripeptide is also easy to substitute or dilute, and the low per-mg cost means very little margin is lost by cutting it. Batch-specific analysis is the only real defence. KPV is also the K in the widely sold KLOW blend, which is where most buyers meet it first; the standalone listings and price range are on the KPV page.
GHK-Cu: the copper peptide, and the CAS that isn’t
GHK-Cu — sold and searched almost as often under the plain-English name copper peptide — is the glycyl-L-histidyl-L-lysine tripeptide complexed with copper, a molecule found naturally in blood plasma. It sits in a slightly different market position from the other three: alongside research supply it has a substantial cosmetic presence, and its literature is concentrated in skin-remodelling, collagen and gene-expression preclinical studies.
It has the second identity trap in this group, and it is a close cousin of the TB-500 problem. The CAS most commonly filed for GHK-Cu, 49557-75-7, actually identifies the copper-free peptide GHK. The copper complex is a distinct substance with a distinct formula (C14H22CuN6O4, 401.91 g/mol). A vendor listing “GHK-Cu, CAS 49557-75-7” is not necessarily lying — that pairing is near-universal in the market — but it does mean the CAS line on the page carries no information about whether you are getting the peptide or the complex.
Current listings, the price band and the full compound sheet are on the GHK-Cu page. GHK-Cu is also the second component of the KLOW blend, which is where it most often appears next to KPV.
Blends: “Wolverine stack,” KLOW, and why they’re harder to verify
Two blend names dominate this corner of the market. The Wolverine stack is BPC-157 and TB-500 sold or discussed together — the market slang has more search volume than some standalone compounds — and it is available as a pre-blended vial. KLOW is a four-part blend built around KPV and GHK-Cu.
We take no position on combinations and make no usage claims about any of them. The sourcing point is narrow and worth stating plainly: a blend multiplies the verification problem. One COA now has to establish identity for two or more molecules, purity for each, and the ratio between them in the vial — and if one of the components is TB-500, the identity ambiguity above rides along into the blend. If you cannot verify the single compounds from a vendor, you certainly cannot verify their blends. The blend listings sit on the BPC-157 + TB-500 blend page and the KLOW page.
What a COA has to show, compound by compound
The general rules for reading a Certificate of Analysis are in how to read a peptide COA. Below is what changes when the compound is one of these four.
| Compound | The specific thing to confirm | What a failure looks like |
|---|---|---|
| BPC-157 | Mass-spec identity consistent with 1419.55 g/mol, on a batch-specific COA | A single COA reused across every batch and every product |
| TB-500 | Whether the material is full-length thymosin beta-4 (~4963 g/mol) or the LKKTETQ fragment — stated explicitly | “TB-500” with a CAS for the full protein and no molecule named anywhere on the COA |
| KPV | Identity consistent with the tripeptide at 342.43 g/mol; salt form (often supplied as the acetate) stated | Purity percentage with no identity confirmation at all |
| GHK-Cu | That the material is the copper complex (401.91 g/mol), not copper-free GHK | CAS 49557-75-7 on the listing and nothing on the COA distinguishing peptide from complex |
Price: compare per milligram, never per vial
These four sit at very different points on the cost curve, and vial sizes differ enough that sticker prices are close to meaningless as a comparison. BPC-157 and TB-500 are commonly sold in 10 mg vials; GHK-Cu and KPV turn up in much larger vials. A 100 mg vial at twice the price of a 10 mg vial is five times cheaper per milligram, and that is the number that actually decides which vendor is expensive.
The full mechanics of that calculation — including the shipping-and-minimum-order effects that flip a ranking — are in price per mg, explained, and the live per-milligram spread across vendors for all four compounds is on the price index. If you are working out concentrations for a reconstituted vial, the reconstitution calculator handles the arithmetic, and bacteriostatic water covers the supply side.
Storage: the same rules, and they matter more for the small ones
All four follow the same handling pattern published on their compound sheets: lyophilised powder kept cold and protected from light; reconstituted material refrigerated and used within a limited window; and in every case, the vendor’s own COA and vial label as the authority. KPV’s sheet adds the point that applies to all of them but bites hardest on short peptides — avoid repeated freeze-thaw cycles.
The reason storage belongs in a sourcing article at all is that a vendor’s cold chain determines whether the batch you receive still matches the COA that was run on it. A clean certificate on a vial that spent a week in a hot warehouse is a historical document. That argument is made in full in how to store research peptides.
Regulatory status, side by side
| Compound | Status as of 2026 |
|---|---|
| BPC-157 | Not FDA-approved. Placed in 503A Category 2 in 2023; removed from that list in April 2026 pending advisory-committee review. Removal is not approval. |
| TB-500 | Not FDA-approved. “Thymosin beta-4, fragment (LKKTETQ), also known as TB-500” appears among bulk substances that may present significant safety risks (Category 2), page current as of 22 Apr 2026. |
| KPV | Not FDA-approved. Nominated and placed in Category 2; nomination later withdrawn by the nominator, FDA noting a lack of human exposure data. |
| GHK-Cu | Not FDA-approved. The copper tripeptide appears among bulk substances flagged as possibly presenting significant safety risks (Category 2), page current as of 22 Apr 2026. |
The short version
If a vendor you are looking at won’t answer the identity question in writing, that answer is itself the result. The five patterns behind most rip-offs are collected on Scam Watch, and the terms used throughout this article are defined in the glossary.
Selected research literature
Vendor pages cite studies constantly, usually as a bare claim with no link. Below are the actual papers behind the research areas described above, with the model each one used stated up front — because that is the part that gets dropped when a citation is turned into marketing copy. Every one of these is preclinical: cell cultures, rodents, or ex-vivo tissue. None of it describes an effect in people, and none of it makes any of these compounds approved for human use.
Each compound below also has a standing page in our research library, where the same citations are kept current and the preclinical-versus-clinical count is shown at the top. The list here is the version that serves this article; the library is the version we maintain.
BPC-157 full record ›
- Chang CH, Tsai WC, Lin MS, Hsu YH, Pang JH. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol. 2011;110(3):774-80. — Model: rat Achilles tendon explants and cultured tendon fibroblasts (ex vivo / in vitro).
- Cerovecki T, Bojanic I, Brcic L, et al. Pentadecapeptide BPC 157 (PL 14736) improves ligament healing in the rat. J Orthop Res. 2010;28(9):1155-61. — Model: rat medial collateral ligament transection, 90-day follow-up.
- Vasireddi N, Hahamyan H, Salata MJ, et al. Emerging use of BPC-157 in orthopaedic sports medicine: a systematic review. HSS J. 2025;21(4):485-95. — Scope: 36 studies from 1993–2024; 35 preclinical, 1 clinical. The single clearest statement of how thin the human evidence base is.
TB-500 / thymosin beta-4 full record ›
- Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-8. — Model: rat full-thickness wound model, plus keratinocyte migration assays.
- Philp D, Goldstein AL, Kleinman HK. Thymosin beta4 promotes angiogenesis, wound healing, and hair follicle development. Mech Ageing Dev. 2004;125(2):113-5. — Model: normal and aged rodents.
- Dubé KN, Smart N. Thymosin β4 and the vasculature: multiple roles in development, repair and protection against disease. Expert Opin Biol Ther. 2018;18(sup1):131-9. — Type: review.
Note that all three describe thymosin beta-4, the full-length protein. That is the identity gap covered above: a paper about the 43-amino-acid protein is not automatically a paper about the LKKTETQ fragment in the vial.
KPV full record ›
- Getting SJ, Schiöth HB, Perretti M. Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides. J Pharmacol Exp Ther. 2003;306(2):631-7. — Model: mouse crystal-induced peritonitis, plus macrophage cultures.
- Dalmasso G, Charrier-Hisamuddin L, Nguyen HT, et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology. 2008;134(1):166-78. — Model: human intestinal epithelial and T-cell lines (Caco2-BBE, HT29-Cl.19A, Jurkat) plus DSS- and TNBS-induced colitis in mice. This is the NF-κB paper the research-area line refers to.
- Kannengiesser K, Maaser C, Heidemann J, et al. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflamm Bowel Dis. 2008;14(3):324-31. — Model: two mouse colitis models (DSS and CD45RB-high transfer).
- Xiao B, Xu Z, Viennois E, et al. Orally targeted delivery of tripeptide KPV via hyaluronic acid-functionalized nanoparticles efficiently alleviates ulcerative colitis. Mol Ther. 2017;25(7):1628-40. — Model: mouse colitis; the point of the paper is the delivery vehicle, not free KPV.
GHK-Cu full record ›
- Maquart FX, Pickart L, Laurent M, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Lett. 1988;238(2):343-6. — Model: fibroblast cultures. The foundational GHK-Cu collagen paper.
- Pickart L, Vasquez-Soltero JM, Margolina A. GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. Biomed Res Int. 2015;2015:648108. — Type: review.
- Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987. — Type: review of gene-expression data.
- Jiang F, Wu Y, Liu Z, Hong M, Huang Y. Synergy of GHK-Cu and hyaluronic acid on collagen IV upregulation via fibroblast and ex-vivo skin tests. J Cosmet Dermatol. 2023;22(9):2598-604. — Model: human dermal fibroblasts and an ex-vivo skin model.
Two of the GHK-Cu entries above are authored by researchers long associated with the compound, and one of the four sits in a cosmetic-science journal. That is not a reason to discount them — it is a reason to read the author list and the journal, which is the same habit that makes you good at reading a COA.
Regulatory and identity sources
- PubChem CID 9941957 — BPC-157 identity, formula and weight (NCBI)
- PubChem CID 45382195 — thymosin beta-4 identity (NCBI)
- PubChem CID 125672 — KPV (NCBI)
- PubChem CID 165429100 — glycyl-L-histidyl-L-lysine copper complex (NCBI)
- FDA — certain bulk drug substances that may present significant safety risks (503A Category 2)
- FDA — bulk drug substances used in compounding under section 503A
- Regenerative and protective actions of the GHK-Cu peptide (NCBI PMC review)
- BPC-157 literature and patent review (NCBI PMC)
For research use only. This article is educational and makes no health, dosing, or usage claims of any kind.