Key Takeaways
- •There is no single formula. At least three distinct compositions share BPC-157 and TB-500, and vendor pages rarely acknowledge that competing versions exist. Read the component list, not the product name.
- •A retail product name is not a composition. Each version is the BPC-157 plus TB-500 pair with one or two more compounds, and only the component list and the per-component milligram split identify which vial is meant.
- •A large number of Cartalax listings print the wrong sequence. Cartalax is the tripeptide Ala-Glu-Asp (AED). Ala-Glu-Asp-Leu (AEDL) is Bronchogen, the bronchial peptide in the same Khavinson series. Listings that describe Cartalax as AEDL are describing a different compound.
- •No published study characterises any of these formulations as a mixture. Published work exists for the individual components only, and nothing in it describes how they behave together in one vial.
- •A blend certificate cannot report purity the way a single-peptide certificate can. With four peptides in one vial, the largest chromatographic peak is not the product, it is a quarter of the product, and the other peaks are not impurities.
- •Every named component is regulated. BPC-157, TB-500, KPV and GHK-Cu all sit in FDA 503A Category 2, all four appear in Health Canada's 9 April 2026 advisory, and BPC-157 and thymosin beta-4 derivatives are both on the WADA Prohibited List.
Summary
There is no single formula. At least three distinct compositions are built on BPC-157 and TB-500, and vendor pages rarely admit that competing versions exist, so the component list is the only thing that identifies what you are looking at. Each version is that pair with one or two further compounds added.
No published study characterises any of these formulations as a mixture; published work exists for the individual components only. A blend certificate also cannot report purity the way a single-peptide certificate can, because with four peptides in one vial the largest peak is a quarter of the product and the other peaks are not impurities.
Two specific things to check on any listing. A large number of Cartalax listings print the wrong sequence: Cartalax is Ala-Glu-Asp, and Ala-Glu-Asp-Leu is Bronchogen, a different compound in the same Khavinson series. And every named component is regulated. All four sit in FDA 503A Category 2 and all four appear in Health Canada's advisory of 9 April 2026.
Several different multi-peptide vials are built on the same pair, BPC-157 and TB-500, with a third or fourth compound added. The pair is the only fixed part, and the single most important thing to understand about these vials is that the rest of the composition varies from listing to listing.
You will find one that is BPC-157 plus TB-500 plus Cartalax. You will find another that is BPC-157 plus TB-500 plus KPV. You will find a third that is BPC-157 plus TB-500 plus KPV plus GHK-Cu. The totals range from 20mg to 80mg per vial and the splits range from even thirds to a 5:1:1:1 ratio. Retail listings often sell more than one of these compositions under the same comic-book nickname, "Deadpool blend", which identifies none of them.
This page is a reference for laboratory and in-vitro research procurement. It explains what each formulation actually contains, what is characterised about each component at the molecular level, why the sequence printed on many Cartalax listings belongs to a different peptide entirely, and why a multi-peptide vial is analytically harder to verify than the sum of its parts. It is limited to composition, molecular characterisation, analytical verification and regulatory status.
The Short Answer
Each of these products is a single lyophilised vial containing several research peptides. The versions in circulation are:
| Version | Components | Typical vial |
|---|---|---|
| Cartalax version | BPC-157, TB-500, Cartalax | 20mg (5/5/10) or 30mg (10/10/10) |
| KPV version | BPC-157, TB-500, KPV | 20mg (5/10/5) |
| Four-peptide version | BPC-157, TB-500, KPV, GHK-Cu | 80mg (10/10/10/50) |
Three vials, one shared pair. The container is identical in every case and the contents are not. In the four-peptide version the single largest component is 50mg of an 80mg vial.
Vendor aggregators list the Cartalax version under at least six different names, including "Cartalax / TB4 / BPC" and "CARTALAX/BPC-157/TB-500", and the component order, the abbreviation for TB-500 and the separator all vary between them.
That naming sprawl is the practical problem. Two researchers comparing notes on "the BPC-157 and TB-500 blend" may be describing vials that share only two of their three or four components, at ratios that differ by a factor of five.
The Components, One at a Time
Before the detail, the five compounds that appear in one version or another, at a glance:
| Compound | What it is | Length | Approx. MW | Molecular characterisation | Appears in |
|---|---|---|---|---|---|
| BPC-157 | Synthetic pentadecapeptide described as derived from a gastric juice protein | 15 residues | 1419 Da | Sequence GEPPPGKPADDAGLV; acetate and arginate salts circulate | All versions |
| TB-500 | Thymosin beta-4, or its Ac-LKKTETQ 17-23 fragment | 43 or 7 residues | ~4900 Da or ~890 Da | The 17-23 fragment spans the G-actin-binding domain | All versions |
| KPV | C-terminal fragment of alpha-MSH | 3 residues | ~342 Da | NF-kappaB and MAP kinase signalling in cell culture; PepT1 transporter substrate | KPV and four-peptide versions |
| Cartalax | Khavinson short peptide bioregulator | 3 residues | ~333 Da | Tripeptide AED; frequently misprinted as AEDL | Cartalax version only |
| GHK-Cu | Copper(II) complex of a tripeptide, isolated 1973 | 3 residues | ~340 Da plus copper | Gly-His-Lys chelating Cu(II) | Four-peptide version only |
Read that table for what it means for verification. Three of the five components are tripeptides within about 10 Da of one another, which is a separation problem for any method run on a vial containing two of them, and one of those tripeptides (Cartalax) is the compound whose identity is most often misprinted.
BPC-157
BPC-157 is a synthetic pentadecapeptide with the sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val (GEPPPGKPADDAGLV), molecular weight approximately 1419 Da. The name comes from a series of peptide fractions isolated and screened by Predrag Sikiric and colleagues at the University of Zagreb, first published in 1993. It is described as derived from a protein found in human gastric juice, but it does not occur naturally as a standalone 15-residue compound.
A structural feature of the literature matters for anyone reading it: Polish reviewers have noted that the overwhelming majority of indexed BPC-157 records trace to Sikiric's group, which has published over 150 papers on the compound, and independent replication is limited.
Salt form is a detail most blend listings omit. Two forms circulate: acetate, which dominates the published literature, and arginate, a basic amino acid salt that is substantially more stable under acidic conditions. A blend certificate that does not name the salt form has not fully described what is in the vial.
TB-500
TB-500 is where the labelling gets genuinely ambiguous, and the ambiguity is rarely disclosed.
Thymosin beta-4 is a naturally occurring 43-amino-acid protein whose primary characterised activity is sequestering monomeric G-actin, controlling how much actin is available to polymerise into filaments. TB-500, as originally characterised in the anti-doping literature, is not that protein. It is the N-terminally acetylated seven-residue fragment Ac-LKKTETQ, corresponding to residues 17 to 23 of thymosin beta-4, which spans the actin-binding domain.
In practice, material sold as TB-500 is sometimes the full-length 43-residue protein and sometimes the 7-residue fragment. Those are not interchangeable: they differ by roughly a factor of six in molecular weight, which means a stated milligram figure corresponds to completely different molar quantities depending on which one is in the vial. Aggregator descriptions of these blends openly note that TB-500 is "sold as either full-length thymosin beta-4 or its 17-23 fragment." Some vendors sidestep the question by writing "TB4" on the label, which resolves nothing.
KPV
KPV is the tripeptide Lys-Pro-Val, molecular weight approximately 342 Da, corresponding to residues 11 to 13 of alpha-melanocyte-stimulating hormone. It is the C-terminal fragment of alpha-MSH, and it is the component in any of these formulations with the best-described molecular mechanism.
In cell culture, nanomolar concentrations of KPV inhibit activation of NF-kappaB and MAP kinase signalling and reduce pro-inflammatory cytokine secretion, and its uptake into intestinal epithelial and immune cells is mediated by the PepT1 transporter. Published work found its activity mechanistically distinct from the core MSH peptides: it is unlikely to act through melanocortin receptors and more likely to act through inhibition of interleukin-1 beta signalling.
Cartalax, and the Sequence Problem
Cartalax is a Khavinson-series short peptide bioregulator, developed at the St. Petersburg Institute of Bioregulation and Gerontology and named, under that series' convention, for cartilage and connective tissue. It sits in the same family as Epitalon, Vilon, Vesugen and Pinealon: very short synthetic sequences proposed to act as tissue-specific regulatory signals.
Here is the problem. Cartalax is the tripeptide Ala-Glu-Asp, abbreviated AED, molecular formula C12H19N3O8, molecular weight approximately 333 Da. A large number of vendor listings, including listings for the three-peptide Cartalax blend specifically, describe Cartalax as Ala-Glu-Asp-Leu (AEDL). AEDL is Bronchogen, the bronchial and pulmonary peptide in the same Khavinson series.
The family structure makes the error easy to see once you know it. AED is the tripeptide core. The tetrapeptides extend it with a fourth residue that carries the tissue specificity: Gly for the pineal peptide Epitalon (AEDG), Leu for the bronchial peptide Bronchogen (AEDL), Arg for the cardiac peptide Cardiogen (AEDR). A listing that prints "Cartalax (Ala-Glu-Asp-Leu)" has named the cartilage peptide and described the lung peptide.
One residue is the whole difference. The three-bead chain is Cartalax (AED). Add a fourth residue and you have a different molecule with a different mass, and which residue you add decides which one: Gly gives Epitalon, Leu gives Bronchogen, Arg gives Cardiogen.
| Khavinson peptide | Sequence | Length | Associated tissue |
|---|---|---|---|
| Cartalax | Ala-Glu-Asp (AED) | 3 | Cartilage and connective tissue |
| Epitalon | Ala-Glu-Asp-Gly (AEDG) | 4 | Pineal |
| Bronchogen | Ala-Glu-Asp-Leu (AEDL) | 4 | Bronchial and pulmonary |
| Cardiogen | Ala-Glu-Asp-Arg (AEDR) | 4 | Cardiac |
This is not a pedantic distinction. It is the difference between two different molecules with different masses, and it determines what a mass spectrometry identity check should be looking for. If a certificate confirms a mass consistent with AEDL while the label says Cartalax, the certificate and the label do not agree, and only one of them can be right.
The published literature on Cartalax itself is thin and largely unreplicated outside the group that created it. The proposed mechanism is modulation of chondrocyte gene expression (SOX9, aggrecan, type II collagen, COMP). It holds no FDA or EMA approval, and in Russia it is marketed as a dietary supplement.
GHK-Cu
GHK-Cu appears only in the four-peptide version, where it is usually the dominant component by mass: 50mg of an 80mg vial, a 5:1:1:1 ratio against the other three.
GHK is the tripeptide glycyl-L-histidyl-L-lysine, molecular weight approximately 340 Da, isolated from human plasma by Loren Pickart in the early 1970s. GHK-Cu is the complex of that tripeptide with copper(II).
The mechanism literature centres on gene expression. GHK-Cu has been reported to modulate both matrix synthesis genes and matrix metalloproteinases, including MMP-2, and Pickart's 2018 review of Broad Institute connectivity data reported GHK altering expression of a large fraction of human genes at a 50% threshold.
Copper is the part of the molecule that makes this component analytically different from the other three. Peptide identity by mass spectrometry does not establish how much copper is bound, so a certificate for a vial containing GHK-Cu has a question to answer that the other components do not raise.
What Is Published About the Blend as a Blend
Nothing. That is the finding, and it is worth stating plainly rather than burying.
No published study characterises any of these three- or four-peptide formulations as a combined product. Vendor and clinic pages that describe the components as "synergistic" are making an inference from four separate single-compound literatures, and even the most detailed guide to the four-peptide version concedes in its own text that no such studies were identified.
Mixtures are not additive by default. One component can alter the solution stability or the chromatographic behaviour of another, and establishing what a combination does requires studying the combination. That study does not exist for any version of this blend.
Why a Blend Is Harder to Verify Than Its Parts
This is the part that matters most for procurement, and it is covered at greater length in our article on the analytical trade-offs of peptide blends.
Above, a single peptide: one peak is the product and everything else is an impurity, so a purity percentage means something. Below, a four-peptide blend: no peak is the product, all four are, and the same percentage has quietly stopped describing the vial.
Purity of what? For a single peptide, a purity figure has an unambiguous referent: how much of the detectable material is the compound on the label. Put three or four peptides in one vial and the arithmetic stops applying. The largest peak is not the product, it is one component of the product, and the other named peaks are not impurities. A single purity percentage on a blend certificate is either measuring one component and calling it the vial, summing the named component areas in a way that would conceal a missing component, or reporting certificates for the input materials rather than for the vial that was filled.
Co-elution. If two components are not chromatographically resolved from each other, one peak integrates as one component and the ratio between them is simply not present in the data. A method that resolves BPC-157 from TB-500 will not necessarily resolve a 342 Da tripeptide from a 333 Da tripeptide. A blend certificate should state that the method separates the components, not merely that a method was run.
Content uniformity. Lyophilisation of a multi-component solution does not guarantee homogeneous distribution through the cake. Components adsorb to fill lines and vial surfaces at different rates and dissolve at different rates on reconstitution. A stated "5mg plus 5mg plus 10mg" is a fill target, not a measurement of what ended up in the vial you received.
Differential stability. Peptides degrade on sequence-specific timescales and are sensitive to different pH and temperature conditions. A single storage condition for a four-component vial is a compromise, and the component with the shortest shelf life sets the real expiry for the product even though the label does not say so.
A blend certificate that is actually worth reading answers seven questions: identity confirmed for each component separately, purity for each component separately, content assay for each against its own reference standard, the ratio and how it was established, the parent lot numbers of the input materials, and evidence that the analytical method resolves the components from one another. LC-MS can confirm identity against each peptide's expected mass, which is exactly the check that would catch an AEDL peptide sold as Cartalax. A certificate that answers only identity and purity at the vial level has described a raw material, not a mixture.
The Fixed-Ratio Trade
A blend removes a degree of freedom. Once components share a vial, they cannot be varied independently, and any change to one is a change to all of them in a fixed proportion.
That matters more here than in a two-component vial because the components are physically and chemically unlike one another: a 15-residue peptide, a 7- or 43-residue actin-binding peptide, and one or two tripeptides within about 10 Da of each other, one of them carrying bound copper. GHK-Cu at 50mg in an 80mg vial dominates the mass. Any experimental design that would treat these as independent variables is impossible in a single vial, and a result obtained with one vendor's ratio does not transfer to another vendor's ratio.
It also makes replication harder. If the internal composition of the vial cannot be verified to the milligram, conditions cannot be recreated and results cannot be compared against other work. That is a reasonable trade for convenience in some contexts and a fatal one in others, but it should be a decision rather than a surprise.
Market Quality Reality
The blend question sits on top of a market-wide sourcing question.
A 2023 survey of peptide products purchased online found that 23% failed label-claim verification, through absence of the stated peptide, presence of unlabelled compounds, or a quantitative mismatch between labelled and actual content. Independent testing aggregating over 6,100 samples across 185 vendors reported that close to 40% of vendors fail to meet their stated purity. Quantity divergence of up to 46% from the advertised figure has been documented, meaning a vial labelled 10mg holding closer to 5.4mg.
The chief science officer of the US Anti-Doping Agency, speaking about grey-market BPC-157, made the same point in blunter language: "You don't even know what you're buying inside that bottle."
Every one of those failure modes is harder to detect in a blend, because the analytical baseline against which you would detect it is exactly the thing a blend certificate struggles to establish. Our standing position on this is on the certificates of analysis page and the quality page, and the independent laboratories that will run this kind of analysis are listed in the peptide testing labs directory.
Regulatory Status of Every Component
None of these compounds is an approved drug in the United States or Canada. This is not a grey area that varies by component.
| Compound | FDA 503A compounding | WADA Prohibited List | Named in Health Canada advisory |
|---|---|---|---|
| BPC-157 | Category 2 since September 2023 | Yes, S0 non-approved substances, added to the 2022 WADA List, prohibited at all times | Yes |
| TB-500 / thymosin beta-4 | Category 2 since September 2023 (fragment LKKTETQ named) | Yes, thymosin beta-4 and its derivatives under S2 growth factors, prohibited at all times | Yes |
| KPV | Category 2 since September 2023 | Not specifically named | Yes |
| GHK-Cu | Not approved as a drug; cosmetic use is a separate regulatory lane | Not specifically named | Yes |
| Cartalax | No approval; marketed as a dietary supplement in Russia | Not specifically named | Not named |
Category 2 on the FDA's interim 503A bulks list means the agency has identified significant safety risks and that compounding pharmacies should not compound the substance. BPC-157, TB-500, KPV and MOTS-C are scheduled for Pharmacy Compounding Advisory Committee review in July 2026, which could move them to Category 1, and that review is the thing to watch rather than any individual vendor's claims about status.
Health Canada's advisory of 9 April 2026 names BPC-157, CJC-1295, DSIP, Epitalon, GHK-Cu, HCG, Ipamorelin, KPV, Melanotan I and II, MOTS-C, NAD+, SS-31, TB-500 and retatrutide. Four of the five compounds that appear in some version of these blends are on that list. The advisory states explicitly that a "research use only" label "does not make these products legal or exempt from regulatory requirements," and that Health Canada has seized unauthorised injectable peptide drugs and works with border authorities to stop unauthorised shipments. Among the quality failures it names are undisclosed ingredients and contamination with solvents, heavy metals, bacteria and fungi, which are the failures a batch certificate exists to rule out.
How to Evaluate a BPC-157 and TB-500 Blend Listing
If you are assessing one of these vials for a research procurement decision, these are the questions that actually separate listings:
- Which formulation is it? Three components or four, and which three. Do not assume from the name.
- What is the split, and does it sum to the stated total? A 20mg vial at 5/5/10 and a 30mg vial at 10/10/10 are different products at different per-milligram costs.
- What sequence does the listing give for Cartalax? AED is correct. AEDL is Bronchogen. A listing that gets this wrong has not verified its own label copy, which is informative about everything else on the page.
- What is TB-500 here, the 43-residue protein or the 7-residue fragment? If the listing does not say, the milligram figure on the label is not interpretable in molar terms.
- What salt form is the BPC-157? Acetate and arginate behave differently under acidic conditions.
- Does the certificate report each component separately? Identity, purity and content assay per component, against separate reference standards, with the ratio stated and the method shown to resolve the components.
- Is the certificate for this vial's lot, or for the input materials? Input certificates describe what went into the process, not what came out.
- Is there a lab verification path you can follow yourself? A report identifier you can check on the issuing laboratory's own site is worth more than a PDF, because a PDF is the most forgeable document in this market.
Frequently Asked Questions
Are the three-peptide and four-peptide versions the same product?
No. The four-peptide version (BPC-157, TB-500, KPV, GHK-Cu) is catalogued here by its composition as GHK-Cu + KPV + BPC-157 + TB-500 80mg. The three-peptide versions are not that product, and a shared retail name does not make them one.
Is it the same as the two-peptide BPC-157 and TB-500 blend?
No. That blend contains BPC-157 and TB-500 only. Every version discussed here is that pair plus at least one more compound.
Which version is "the real one"?
Neither. There is no standard-setting body for retail peptide blend names, no originator formulation, and no reason to expect convergence. The Cartalax version and the KPV version are both widely sold, by different vendors, with no relationship between them beyond two shared components.
Why is Cartalax described as a cartilage peptide?
Because of the Khavinson naming convention: each peptide in the series is named for the tissue its developers associated it with, and Cartalax is the series' cartilage peptide. The name records the series' nomenclature, not a measured property of the vial.
Does a higher total milligram figure mean a better vial?
No. The 80mg four-peptide version is 50mg GHK-Cu, so its headline number is dominated by one component. Compare per-component milligrams, not vial totals.
Are these compounds legal to buy?
The compounds are sold widely as research materials. Health Canada's position is that unauthorised injectable peptide drugs are illegal in Canada and that a research-use-only label changes nothing about that. The FDA has not approved any of them, and four sit in 503A Category 2.
Which of these compositions does Volta stock?
Only the four-peptide version, and not the Cartalax version at all. The four-peptide version is the one we stock, catalogued by its composition: GHK-Cu + KPV + BPC-157 + TB-500 80mg holds all four in one vial, and its certificate reports a purity figure for each of the four separately. The components are also sold as single vials, BPC-157, TB-500, KPV and GHK-Cu, alongside one two-peptide blend, BPC-157 + TB-500. We do not stock Cartalax. Single vials are the more defensible purchase for anyone who needs the ratio to be a variable rather than a constant, and they are the only way to get a certificate whose purity figure means what a purity figure normally means.
Sources
Primary literature and regulatory positions consulted for this article:
- Sikiric et al., original BPC-157 characterisation, University of Zagreb, 1993 onward
- BPC-157 as an Investigational Peptide Therapeutic, Pharmaceutics, 2026
- Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, 2012
- Mechanistic study comparing the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides, 2003
- Study of PepT1-mediated uptake of the tripeptide KPV, Gastroenterology, 2008
- Khavinson short peptide bioregulator series, St. Petersburg Institute of Bioregulation and Gerontology
- Pickart, review of GHK-Cu in the light of gene expression data, 2018
- FDA interim 503A bulk drug substances list, Category 2 additions of September 2023
- WADA Prohibited List, S0 and S2, 2022 onward, and USADA advisories
- Health Canada advisory on unauthorised injectable peptide drugs, 9 April 2026
- STAT News, BPC-157: the peptide with big claims and scant evidence, February 2026
This article is written for laboratory and in-vitro research procurement. Nothing in it is medical advice, and no component discussed here is approved for human use in Canada or the United States.
