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GHK-Cu Research Overview: The Copper Peptide, Plus GLOW vs KLOW Explained

By The Bionova Club Team

Disclosure: Bionova Club sells GHK-Cu and the GLOW and KLOW blends, linked below.

Research use only. Bionova products are sold strictly for in-vitro and laboratory research by qualified professionals. They are not drugs, food, or cosmetics, are not approved by the FDA, and are not for human or veterinary use. Nothing in this article is medical advice or a claim about effects in people.

GHK-Cu is the copper(II) complex of the tripeptide glycine-histidine-lysine, and it is easy to recognize in the lab: the material is blue. It is also a component of two multi-peptide research blends, GLOW and KLOW. That has created plenty of confusion about how the three products relate.

This overview covers what GHK-Cu is, where it came from, what laboratory research has examined, and how the GLOW and KLOW blends differ from GHK-Cu on its own.

What is GHK-Cu?

GHK is a tripeptide, a chain of three amino acids: glycine, histidine and lysine (glycyl-L-histidyl-L-lysine). GHK binds copper(II) ions with high affinity, and the copper complex is called GHK-Cu. The copper is what gives GHK-Cu its characteristic blue color.

  • Sequence: Gly-His-Lys (GHK), complexed with Cu²⁺
  • Peptide length: 3 amino acids
  • Molecular weight (GHK, without copper): ~340 g/mol
  • Appearance: Blue to blue-violet lyophilized powder
  • First described: 1973, as a tripeptide in human serum
  • Supplied as: Lyophilized powder

A short history

GHK was first reported in 1973 by Loren Pickart and colleagues. They described a tripeptide in human serum that affected the behavior of cultured liver cells (Pickart & Thaler, 1973, Nature New Biology). Its copper binding was characterized later: in 1980 Pickart and colleagues reported that the tripeptide readily forms complexes with copper(II) (Pickart et al., 1980, Nature), and in 1981 Lau and Sarkar measured the stability of those complexes and showed that GHK can compete with albumin for copper(II) (Lau & Sarkar, 1981, Biochemical Journal).

What has GHK-Cu research examined?

GHK-Cu has been studied in cell culture, in animal models and in formulation research. A few research threads stand out.

Collagen and extracellular matrix in cell culture

One of the earliest and most cited lines of work looked at extracellular matrix production in fibroblast cultures. In 1988, Maquart and colleagues reported that the GHK-Cu complex stimulated collagen synthesis in cultured fibroblasts (Maquart et al., 1988, FEBS Letters). This finding underpins much of the later interest in GHK-Cu as a research tool in matrix biology.

Gene-expression studies

More recent work has used gene-expression datasets to explore which pathways GHK appears to influence in vitro. A 2018 review by Pickart and Margolina summarizes these data. It describes GHK as associated with changes in expression across many genes linked to tissue remodeling, antioxidant response and other cellular processes (Pickart & Margolina, 2018, International Journal of Molecular Sciences).

An earlier review by the same group surveyed the cellular pathways studied in skin-model research (Pickart et al., 2015, BioMed Research International).

Reading the literature carefully

Two cautions apply. First, a substantial share of GHK-Cu literature, including the reviews above, comes from researchers closely associated with its discovery. Second, gene-expression associations from cell lines are hypothesis-generating. They are not demonstrations of effects in whole organisms. GHK-Cu is not approved by the FDA as a drug.

GHK-Cu vs GLOW vs KLOW

GLOW and KLOW are retail names for pre-blended research vials that combine GHK-Cu with other peptides. The names describe contents, not new molecules.

  • What it is
    • GHK-Cu: A single copper tripeptide
    • GLOW blend: GHK-Cu + BPC-157 + TB-500
    • KLOW blend: GHK-Cu + BPC-157 + TB-500 + KPV
  • Bionova vial
  • Amounts per vial (from Bionova's product pages)
    • GHK-Cu: GHK-Cu 50 mg
    • GLOW blend: GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg
    • KLOW blend: GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg, KPV 10 mg
  • Appearance
    • GHK-Cu: Blue powder
    • GLOW blend: Blue powder (from GHK-Cu)
    • KLOW blend: Blue powder (from GHK-Cu)
  • Studied as a formulation?
    • GHK-Cu: Yes, as a single compound
    • GLOW blend: No published studies of the blend
    • KLOW blend: No published studies of the blend

What's in GLOW?

GLOW combines GHK-Cu with BPC-157 and TB-500. Bionova's GLOW product page lists GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg, for 70 mg total, so GHK-Cu makes up most of the vial by weight. BPC-157 and TB-500 are themselves distinct molecules with separate research literatures. Our BPC-157 vs TB-500 research overview explains how they differ.

What's in KLOW?

Bionova's KLOW product page lists GHK-Cu 50 mg plus 10 mg each of BPC-157, TB-500 and KPV, for 80 mg total. KPV is the tripeptide lysine-proline-valine, which corresponds to the C-terminal end of alpha-melanocyte-stimulating hormone (α-MSH). KPV has been studied mainly in intestinal-cell and mouse models of inflammatory signaling (Dalmasso et al., 2008, Gastroenterology; Kannengiesser et al., 2008, Inflammatory Bowel Diseases). None of that work involved GHK-Cu, BPC-157 or TB-500.

Has GLOW or KLOW been studied as a blend?

Not as far as we can find. Each component has its own published literature, but we found no peer-reviewed studies of the GLOW or KLOW combinations themselves. Results reported for one compound alone cannot be assumed to carry over when it is combined with others.

The closest related work is a 2026 exploratory rat study that compared BPC-157, TB-500 and their combination. It reported no additive difference for the combination (Biçer et al., 2026). That study did not include GHK-Cu or KPV.

Choosing a format for a study design

The choice usually comes down to experimental design rather than "better or worse":

  • GHK-Cu alone suits studies focused on the copper peptide as a single variable.
  • GLOW or KLOW may suit designs that intentionally include all components at a fixed ratio, with fewer separate items to track.
  • Separate single-compound vials give the most control when each variable needs to be varied or tested independently.

You can compare all of our multi-compound formats in the research blends category.

Storage notes for GHK-Cu and copper-peptide blends

  • Expect blue. A blue lyophilized powder is normal for GHK-Cu, GLOW and KLOW because of the bound copper. Material that looks wet, clumped or an unexpected color should be reported to the supplier.
  • Keep it sealed, cold and dry. Store the lyophilized powder in its original sealed container, cold, dry and away from light.
  • Warm before opening. Let a sealed container reach room temperature before opening so moisture does not condense on the powder.
  • Follow the label. Store as directed on the product label.

Key takeaways

  • GHK-Cu is the copper complex of the tripeptide Gly-His-Lys, first described in 1973. The material is blue because of the bound copper.
  • Laboratory research has examined GHK-Cu in fibroblast collagen synthesis and in gene-expression studies, mostly in vitro.
  • GLOW contains GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg (70 mg total). KLOW contains GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg and KPV 10 mg (80 mg total). Both figures are from the product pages.
  • Neither blend has been studied as a formulation, so evidence for each component applies only to that component.
  • All of these are research materials only and are not approved for human use.

Frequently asked questions

What is GHK-Cu?

GHK-Cu is the copper(II) complex of GHK, a tripeptide made of glycine, histidine and lysine. It was first reported in human serum in 1973 and has since been studied in cell culture and animal research.

Why is GHK-Cu blue?

The blue color comes from the copper(II) ion bound to the peptide. GHK-Cu powder, and blends that contain GHK-Cu such as GLOW and KLOW, are normally blue.

What is the difference between GLOW and KLOW?

GLOW's product page lists GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg (70 mg total). KLOW's product page lists the same three components at the same amounts plus KPV 10 mg (80 mg total). KPV is a tripeptide derived from the C-terminal end of alpha-MSH.

Have GLOW or KLOW blends been studied?

We found no published peer-reviewed studies of the GLOW or KLOW combinations as formulations. Each component has been studied individually, mainly in cell and animal models.

Is GHK-Cu the same as the copper peptides in cosmetics?

GHK-Cu is the best-known copper peptide and appears in cosmetic formulation research. Cosmetics are a separate product category with their own regulations. Bionova's GHK-Cu is a research material for laboratory use only, not a cosmetic, and not for human use.

How should GHK-Cu be stored?

Store the sealed lyophilized powder cold, dry and away from light, and let the sealed container reach room temperature before opening. Store as directed on the product label.

Shop for your research: GHK-Cu, or the GLOW and KLOW blends that include it, for laboratory research. Use code CLUB10 at checkout for 10% off.

References

  1. Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973. https://pubmed.ncbi.nlm.nih.gov/4349963/
  2. Maquart FX, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Lett. 1988. https://pubmed.ncbi.nlm.nih.gov/3169264/
  3. 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. https://pubmed.ncbi.nlm.nih.gov/29986520/
  4. Pickart L, et al. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. Biomed Res Int. 2015. https://pubmed.ncbi.nlm.nih.gov/26236730/
  5. Dalmasso G, et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology. 2008. https://pubmed.ncbi.nlm.nih.gov/18061177/
  6. Kannengiesser K, et al. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflamm Bowel Dis. 2008. https://pubmed.ncbi.nlm.nih.gov/18092346/
  7. Biçer O, et al. Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study. Joint Dis Relat Surg. 2026. https://www.jointdrs.org/full-text/1851
  8. Pickart L, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature. 1980. https://pubmed.ncbi.nlm.nih.gov/7453802/
  9. Lau SJ, Sarkar B. The interaction of copper(II) and glycyl-L-histidyl-L-lysine, a growth-modulating tripeptide from plasma. Biochem J. 1981. https://pubmed.ncbi.nlm.nih.gov/7340824/

For laboratory research use only. Not for human consumption.