GHK-Cu copper peptide: what you need to know

GHK-Cu is a tripeptide — glycine, histidine, lysine — which binds a copper ion. In cosmetics, it appears on the list of ingredients under its INCI name, Copper Tripeptide-1, and it is the copper bound to the peptide that gives the serum its blue colour. Here is what the studies measure, and what they do not measure.

What is the copper peptide GHK-Cu?

A peptide is a short chain of amino acids. This one contains three — glycine, histidine, lysine — hence the initials GHK; ‘Cu’ is the chemical symbol for copper, the ion bound by the chain. A tripeptide and a copper ion: the name says it all, and that is all it takes to understand what the product is.

Loren Pickart described this tripeptide in human plasma in 1973. Its concentration in plasma decreases with age: from around 200 ng/mL at the age of twenty to around 80 ng/mL at the age of sixty, according to the review by Loren Pickart and Anna Margolina (Int. J. Mol. Sci. 2018;19(7):1987). This finding is often reproduced verbatim, without acknowledging its limitation — even though it is crucial: a serum is applied to the skin and does not restore any levels within the body. It is a cosmetic application, and nothing more.

On the label, the ingredient is listed as Copper Tripeptide-1. Marketing terms such as ‘copper peptide’ do not replace this INCI name, and it is this name you should look for.

Why is the GHK-Cu serum blue?

The colour does not come from a dye. When bound to the peptide, the copper ion absorbs a portion of the visible spectrum and reflects blue light. This is exactly what gives its colour to covellite, that copper mineral with an almost midnight-blue hue described in 1832 by the Italian mineralogist Nicola Covelli — and which gave its name to Maison Covelli.

The intensity of the colour depends on the formula and may vary from one batch to another. It is therefore not an indicator of quality, and it disappears as soon as the serum is applied to the skin.

What do studies on ‘GHK-Cu’ actually measure?

Four studies are cited by the leading review, that of Pickart and Margolina published in 2018. They focus on creams and preparations, never on the serum of any particular brand. The first two were only ever published as abstracts presented at a dermatology congress in 2002 (Leyden et al., 2002): we cite them as reported in the review, without having seen their data.

The third study is the most frequently cited (Abdulghani et al., 1998): in this comparison, increased collagen production was observed in 70 per cent of participants, compared with 50 per cent using a vitamin C cream and 40 per cent using retinoic acid. This is the result as reported, and it must be interpreted with caution: retinoic acid is a prescription-only active ingredient, with which a cosmetic product cannot be compared. We have not been able to read this 1998 publication: the figures are those reported by the review.

These caveats apply to the entire body of evidence. The trials are small-scale, outdated, industry-funded, and largely stem from the same research environment, and none specify the concentration used. The most recent, from 2016, split 40 women into two groups: each applied a GHK-Cu serum in nano-carriers to one half of the face and, to the other half, either the same serum without the active ingredient or a commercial product (Badenhorst et al., 2016). The serums tested were supplied by a brand, and this formulation is not that of an ordinary water-based serum. These studies constitute literature on the ingredient, not evidence of a finished product. Moreover, there are no studies specifically on Maison Covelli serums, and we do not imply otherwise.

What a copper peptide serum promises, therefore, remains a cosmetic claim, one that relates to appearance: when applied daily, the skin appears smoother and more even-toned, fine lines are less noticeable, and the facial contour appears firmer.

How long does it take to see results?

Eight to twelve weeks. This is the timeframe covered by published trials, and the only one that has been documented; shorter periods have not been studied. A promise of results within fifteen days therefore suggests more than has actually been measured.

In practice, it is best to change only one thing at a time in your routine during these two to three months. Otherwise, by the end, there is no way of telling where the difference comes from.

What can GHK-Cu be combined with?

This section concerns formulation chemistry and standard practice, not clinical trials: there is no primary literature on the combination of GHK-Cu with another active ingredient applied to the skin.

A note on retinol: the literature does not describe any chemical incompatibility between the two, and the reason for using them separately relates to skin tolerance, not chemistry. Some raw material technical data sheets nevertheless advise against combining them — we prefer to mention this rather than claim there are absolutely no reservations.

How do you interpret a percentage on a bottle?

This is where market figures can be misleading. Commercial solutions of Copper Tripeptide-1 are sold at 2,000 or 5,000 ppm, and the recommended incorporation rates refer to the solution, not to the peptide alone. These recommendations vary from one supplier to another by a factor of around two hundred.

Consequently, a ‘1 per cent GHK-Cu serum’ usually refers to 1 per cent of the solution, and therefore a much smaller proportion of the peptide. Two bottles labelled with the same percentage may not mean the same thing. The question to ask is not ‘how much?’ but ‘what does the percentage refer to?’.

A word on the ingredients list, whilst we’re on the subject: it lists the ingredients in descending order by weight, but those present in proportions of less than one per cent may appear in any order. A peptide at the end of the list is therefore normal, and its position does not indicate any specific percentage.

Is the ‘GHK-Cu’ permitted in cosmetics?

Yes. In a serum or cream, Copper Tripeptide-1 is an approved cosmetic ingredient. All cosmetic products are notified to the European CPNP portal before being placed on the market and are the responsibility of a responsible person established in the EU — which guarantees traceability, not an assessment of efficacy.

The packaging itself must bear seven mandatory details: the name and address of the responsible person, the nominal contents, a use-by date or a period of use after opening, precautions for use, the batch number, the product’s function and the list of ingredients. This is the simplest checklist for identifying a compliant product.

Injectable ‘GHK-Cu’, however, is a completely different matter: it is not a cosmetic product. Maison Covelli sells only cosmetics intended for application to the skin, and any enquiry regarding an injection should be addressed to a healthcare professional.

How should it be applied, and what precautions should be taken?

A few drops onto clean, dry skin, in the morning or evening, before applying your moisturiser. Do not use pure vitamin C or an exfoliant at the same time: both work at a low pH.

Before applying it to the whole face for the first time, carry out a patch test on the inside of your elbow, monitoring the area for twenty-four hours; this is standard practice for a product containing a metallic active ingredient. Copper is considered a mild sensitiser compared to other metals — a finding recalled by a study carried out on skin cells in culture (Li et al., 2016) — and the reactions reported are mainly localised and mild. Do not apply the serum to broken or irritated skin. Finally, there is no reliable data regarding pregnancy and breastfeeding: this matter should be discussed with a doctor rather than with the brand.

The Serum No. 1 · Copper Peptide from Maison Covelli is part of the collection : 30 ml, a glass bottle with a dropper, formulated and manufactured in Italy by a certified ISO 22716 contract manufacturer. The exact concentration is stated on the packaging. The brand’s other serums are featured in the blog.

Sources

These studies concern the ingredient, never a Maison Covelli serum. Loren Pickart, author of the review, discovered the peptide and founded a brand of copper-based cosmetics.

• 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.
• Leyden J, Stephens T, Finkey M, Appa Y, Barkovic S. Skin Care Benefits of Copper Peptide Containing Facial Cream. Abstract, 60th Annual Meeting of the American Academy of Dermatology, New Orleans, 2002, p. 68 — cited as reported by Pickart and Margolina (2018); no online version.
• Leyden J, Stephens T, Finkey M, Barkovic S. Skin Care Benefits of Copper Peptide Containing Eye Creams. Abstract, same meeting, 2002, p. 69 — cited as reported by Pickart and Margolina (2018); no online version.
• Abdulghani A, Sherr A, Shirin S, et al. Effects of topical creams containing vitamin C, a copper-binding peptide cream and melatonin compared with tretinoin on the ultrastructure of normal skin. Dis Manag Clin Outcomes 1998;1(4):136-141.
• Badenhorst T, Svirskis D, Merrilees M, Bolke L, Wu Z. Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters. J Aging Sci 2016;4(3):166.
• Li H, Toh PZ, Tan JY, et al. Selected Biomarkers Revealed Potential Skin Toxicity Caused by Certain Copper Compounds. Sci Rep 2016;6:37664.

This article describes cosmetic products and their ingredients. It focuses on the appearance of the skin and is not a substitute for medical advice. In the event of any changes to your skin, during pregnancy or in the event of a known intolerance, please consult your doctor.

Maison Covelli sells only cosmetic products intended for application to the skin. We do not provide any information on injectable preparations.