What Is in a Blend? KLOW, BPC-157 + TB-500 and CJC-1295 + Ipamorelin

Last reviewed 9 August 2026

Three preparations in this catalogue arrive as a single lyophilised cake containing more than one named peptide. KLOW names four. BPC-157 + TB-500 names two. CJC-1295 + Ipamorelin names two. Everything awkward about a blend follows from one structural fact: the vial declares a total mass, and a total mass is not a composition.

What follows sets out what those designations name, what a label of that form leaves open, and what the indexed literature holds for each combination as a combination. That last section is the shortest here, and the brevity is the finding rather than an omission.

A blend designation is a trade name, not a chemical name

KLOW has no International Nonproprietary Name, no CAS registry number, no PubChem record and no pharmacopoeial monograph, because it is a mixture rather than a substance. BPC-157 + TB-500 and CJC-1295 + Ipamorelin are component lists joined by a plus sign, and the plus sign carries no specification: not a ratio, not a tolerance, not an order. Two vials bearing one blend name need not hold the same proportions. The components are a different matter: each is a registered entity with its own formula, mass and identifiers.

Two entries there do extra work, because a single component name can be ambiguous before any blending occurs. CJC-1295 is applied to two molecules — the albumin-binding analogue carrying an additional lysine bearing a 3-maleimidopropionyl group, and the unconjugated 29-residue tetrasubstituted GRF(1–29) without it — which differ by 279.3 in average mass. Those are different substances, not variant formulations, and the indexed human trial data were generated with the albumin-binding form (Teichman et al., 2006). The CJC-1295 entry sets the distinction out in full.

Separately, a PubChem name search for GHK-Cu returns six compound records: the neutral 1:1 complex above, a cationic form (402.92), an anionic form (400.90), the uncomplexed tripeptide, and two bis-peptide species carrying two GHK units per copper centre (742.3 and 744.3). GHK-Cu is a metal bound to a peptide, and charge and stoichiometry are part of its identity.

What the label fixes, and what it leaves open

A label of the usual form fixes two things: which components are present by name, and their combined mass. It leaves open the mass fraction of each, and so everything downstream of that fraction. A total is one number, and four numbers cannot be recovered from one. The mass ratio belongs to the manufacturing specification: it must be read from a certificate of analysis and recorded, or determined by assay. It cannot be inferred from the fill mass, the reconstitution volume or the appearance of the cake. Reading a certificate of analysis covers what such a document does and does not establish.

The arithmetic consequence

Reconstitution arithmetic is unchanged by blending, in a way easily misread as reassuring. Concentration is the mass of solid divided by the volume of diluent, so an 80 mg total fill taken into 2 mL gives 40 mg/mL — the concentration of total peptide, not of any component. The per-component figure is that total multiplied by the component’s mass fraction, the one quantity the label does not state. On a single-component vial the two coincide, which is why the distinction stays invisible until a blend exposes it. The general relation is set out in how to calculate peptide concentration after reconstitution, and the reconstitution calculator resolves it for a single stated strength.

A second trap sits behind the first: mass fractions and molar fractions are different numbers. A four-component preparation split equally by mass would hold about 4.1 times the molar quantity of KPV as of BPC-157, since 342.43 divides into a given mass roughly 4.1 times as often as 1419.5 does. For the two-component secretagogue blend the factor is 5.12 with the albumin-binding CJC-1295 and 4.73 with the unconjugated form — so a molar ratio turns on a component ambiguity the name does not resolve.

The analytical consequence

Characterising a mixture is a different problem from characterising a substance, and three familiar shortcuts stop working.

• A single expected mass speaks to one component. A mass consistent with 1419.5 is consistent with BPC-157 being present. It says nothing about the other three species and nothing about proportions.
• Peak areas are not composition. Reversed-phase separation resolves species differing in chain length and hydrophobicity, but molar absorptivity at the detection wavelength differs between them, so relative peak area is not relative mass without a reference standard for each component. Kwok and colleagues (2013) reported one extraction and chromatographic method covering seven bioactive peptides — GHRP-1, GHRP-2, GHRP-6, ipamorelin, hexarelin, CJC-1295 and N-acetylated LKKTETQ — in horse plasma, each detected as its own analyte.
• A single purity percentage is undefined for a mixture until the analyte is named. On a blend the figure can only mean the proportion of total material accounted for by the named species taken together, which is what the published floor of greater than 99% states; it is a different measurement from the purity of any one component.

One component brings its own handle: copper has two stable isotopes, ⁶³Cu and ⁶⁵Cu, at published abundances of 0.6915 and 0.3085, so a copper-bearing species carries a two-peak signature no free peptide produces, and copper can be quantified as an element independently of any peptide assay.

What the indexed literature contains for these combinations

The searches below were run on 9 August 2026, and each count is given with the query that produces it.

Rodent models

Biçer and colleagues (2026) reported a four-arm experiment in 32 male Sprague-Dawley rats using a standardised Achilles tendon transection model: control, BPC-157 alone, TB-500 alone, and the two together. They reported higher maximum-load-to-failure values in the BPC-157 and TB-500 groups than in controls, reaching statistical significance in the TB-500 group; increased type I collagen organisation on Sirius red birefringence analysis, particularly in the TB-500 group; and that the combination arm conferred no additional advantage over either agent alone. This is the only located experiment in which any two components of these three blends were given together.

Human studies

Two components carry human trial data of their own. (Human trials exist for thymosin β4, the parent protein, but not for the acetylated fragment supplied as TB-500 — the distinction is set out in the TB-500 entry.) Neither trial involved a combination.

• Teichman and colleagues (2006) reported two randomised, placebo-controlled, double-blind ascending-dose trials of CJC-1295 in healthy subjects aged 21 to 61: increases in mean plasma growth hormone and IGF-I concentrations that scaled with the amount given, an estimated half-life of 5.8 to 8.1 days, and no serious adverse reactions. The material was the albumin-binding form.
• Beck, Sweeney and McCarter with the Ipamorelin 201 Study Group (2014) reported a multicentre, double-blind, placebo-controlled phase 2 trial in patients following bowel resection, 114 of whom entered the analysis populations. On the key efficacy endpoint, time to tolerance of a standardised solid meal, they reported a median of 25.3 hours against 32.6 for placebo, p = 0.15, and concluded there were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses.

What the searches return, and what that is evidence of

• PubMed, KLOW: 199 records, none about a peptide preparation. The term maps to the Norwegian surname Kløw in author lists — chiefly cardiology and radiology. Restricting to KLOW[Title/Abstract] leaves 32. Narrowing to KLOW AND peptide leaves seven, and none of those describes a multi-peptide preparation either: two of the seven carry no Kløw author at all, and two are atrial natriuretic factor studies returned by the second term rather than the first.
• PubMed, “BPC-157” AND “KPV”: zero records.
• PubMed, “BPC-157” AND “GHK”: five records, all 2026 narrative reviews mentioning both compounds separately.
• PubMed, “CJC-1295” AND “ipamorelin”: nine records — eight narrative reviews and one equine doping-control method paper. Europe PMC returns seventeen for the same terms, adding preprints and further reviews. No interventional study of the pair appears in either.
• ClinicalTrials.gov: BPC-157, ipamorelin, CJC-1295, TB-500 and GHK-Cu each appear as a registered intervention. No registration names a multi-peptide blend, and a search for KLOW returns one unrelated study.

An absence of records is a statement about the published record on the date searched. It is not a finding of safety and not a finding of no effect. It is the reason the sections above are written about components rather than about preparations.

The grading consequence

1. A blend cannot be graded above its weakest-evidenced component. Any statement about the preparation must hold for everything in the vial, so the component with the thinnest literature sets the ceiling.
2. Blending generates no evidence of its own. A combination is a distinct object of study — distinct kinetics, distinct impurity profile, distinct stability behaviour — and across these three preparations it has been studied once, in one rodent model, for one of the three pairings. Adding a component adds an unknown; it does not average two knowns.

How the A–E scale is defined and reviewed is set out in how evidence grades work on this site, and the current grade for each preparation is published in its library entry.

The anti-doping consequence

A blend has no anti-doping classification of its own, and its components need not share one. On the 2026 World Anti-Doping Agency Prohibited List, BPC-157 falls under S0, Non-Approved Substances — the residual class for a pharmacological substance not addressed elsewhere on the List and holding no current approval by any governmental health authority for human therapeutic use. TB-500 is named in S2.3, Growth Factors and Growth Factor Modulators, as Thymosin-β4 and its derivatives e.g. TB-500, an entry added with effect from the 2018 List. CJC-1295 and ipamorelin both fall under S2.2.4, Growth Hormone Releasing Factors, the former as a GHRH analogue and the latter as a growth hormone secretagogue. GHK-Cu and KPV are not named anywhere on the List.

The BPC-157 and TB-500 preparation therefore spans two sections differing in more than numbering: substances in S0 are Specified Substances and those in S2 are non-Specified Substances, a distinction bearing on how a sanction is determined under the World Anti-Doping Code. There is no single answer to which class that preparation belongs to, because the question is asked of a vial and the List answers about substances. The structural distinction is set out in BPC-157 and TB-500 distinguished.

What characterising a mixture requires

Four things characterise a mixture: a declared mass ratio lot by lot; an identity confirmation for every named component in that lot; a stability study of the components co-formulated; and a study of the combination as a combination. Only the last is a research question. The first three are documentation and analysis, which is why the compound library carries the identity and evidence record component by component, and the blend entries point back to it.

The three preparations in this catalogue

All three are supplied as a lyophilised solid in a sealed vial, and in each case the labelled mass is the combined mass of all components: KLOW 80mg (K80) — BPC-157, TB-500, GHK-Cu and KPV, 80 mg total; BPC-157 + TB-500 20mg (BB20), 20 mg total; CJC-1295 + Ipamorelin 10mg (CP10) — CJC-1295 and ipamorelin, 10 mg total. The first two sit in the library’s healing and repair class and the third in the growth hormone secretagogue class. Related: the scope of the GHK-Cu literature, how to read the sequences, and the glossary.

References

1. Biçer O, Adanir O, Güleryüz Y, Balci EC, Dinçel YM, Yenigün MY, Aydin C, Bayrak BY. Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study. Jt Dis Relat Surg. 2026;37(3):822–837. PMID 42542926. DOI 10.52312/jdrs.2026.2951. Model: rodent.
2. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799–805. PMID 16352683. DOI 10.1210/jc.2005-1536. Model: human trial.
3. Beck DE, Sweeney WB, McCarter MD; Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014;29(12):1527–34. PMID 25331030. DOI 10.1007/s00384-014-2030-8. Model: human trial.
4. Kwok WH, Ho ENM, Lau MY, Leung GNW, Wong ASY, Wan TSM. Doping control analysis of seven bioactive peptides in horse plasma by liquid chromatography-mass spectrometry. Anal Bioanal Chem. 2013;405(8):2595–606. PMID 23318763. DOI 10.1007/s00216-012-6697-9. Model: non-rodent animal; analytical method.
5. World Anti-Doping Agency. Prohibited List 2026, in force from 1 January 2026: S0 (Non-Approved Substances), S2.2.4 (Growth Hormone Releasing Factors), S2.3 (Growth Factors and Growth Factor Modulators). Model: regulatory.
6. UK Anti-Doping. 2018 Prohibited List — Summary of Changes, recording the addition of Thymosin-β4 and its derivatives (e.g. TB-500) to category S2.3. Model: regulatory.
7. United States Anti-Doping Agency. BPC-157: Experimental Peptide Creates Risk for Athletes, stating that BPC-157 is prohibited in the category S0. Model: regulatory.
8. National Center for Biotechnology Information. PubChem Compound Summaries, retrieved 9 August 2026: CID 9941957, 62707662, 165429100, 73587, 125672, 91971820, 56841945, 9831659. Model: chemical registry.
9. Commission on Isotopic Abundances and Atomic Weights (IUPAC). Copper: ⁶³Cu 0.6915(15), ⁶⁵Cu 0.3085(15); standard atomic weight 63.546(3). Model: reference data.
10. PubMed, Europe PMC and ClinicalTrials.gov searches as described, all run on 9 August 2026.