In what forms does copper exist in cosmetics?

The copper gluconate (INCI: Copper Gluconate) is a copper salt of D-glucuronic acid, which is a constituent of glycosaminoglycans (hyaluronic acid). Light blue to bluish-green in colour, it is created following a reaction of glucuronic acid with cupric oxide or cupric carbonate. The role of gluconate is to increase the bioavailability of copper through the epidermis. In other words, it allows the skin to assimilate copper more easily.

What are the benefits of copper gluconate?

One of the primary benefits of copper gluconate in skincare is its potential to stimulate the proliferation of fibroblasts, and to promote the synthesis of collagen and elastin, resulting in firmer and smoother skin. It also possesses antioxidant properties. Involved in several enzymatic systems, copper is a cofactor of superoxide dismutase, an antioxidant enzyme. It thus helps to combat free radicals, thereby helping to prevent the formation of premature wrinkles and fine lines on the skin and to inhibit cellular oxidative effects (membrane damage and lipid peroxidation). Copper gluconate also has potential healing capabilities. In fact, studies have shown that its topical application can induce the expression of integrins in keratinocytes, affecting cellular mobility during the re-epithelialisation phase of the healing process. Finally, copper gluconate also has the ability to inhibit and prevent microbial growth.

What are the potential dangers of using copper gluconate in cosmetics?

Copper gluconate is generally regarded as being safe in typical quantities ranging from 0.001 to 1.0%. Studies have demonstrated its safety and effectiveness in numerous skincare products. No study has highlighted any specific dangers associated with its use. It is suitable for all skin types, including sensitive skin, and it does not cause any adverse effects. Pregnant women and infants can also use it, as it has not been associated with any health risks for them.

Thecopper oxide (INCI: Copper Oxide) is a chemical compound resulting from the combination of oxygen with copper. Present in the form of a black powder, it is the result of the oxidation of metallic copper.

What are the benefits of copper oxide?

Socks, nurse uniforms, hospital clothing, pillowcases... a variety of textiles have been developed, where insoluble cupric oxide has been introduced into the polymer threads (polyester, nylon, etc.) to take advantage of the properties of copper.

• Copper oxide socks to prevent and treat various acute or chronic infections of athlete's foot and diabetic foot, optimise wound healing, increase the stability and integrity of the skin in order to reduce the risk of wounds and secondary infection, and improve blood circulation and the efficiency of the immune system.

• pillowcases infused with copper oxide to reduce the depth of facial wrinkles and improve the appearance of the skin, by inducing the proliferation of dermal fibroblasts, increasing the synthesis of skin proteins (collagen, elastin, fibronectin, integrin) and stabilising the extracellular matrix.

• Dressings containing cupric oxide to control wound and dressing contamination, induce angiogenesis, enhance skin regeneration and stimulate wound healing.

What are the potential dangers of using copper oxide in cosmetics?

The safety of using copper oxide-infused products has been examined in several clinical and non-clinical studies. In all the studies, no adverse reactions were recorded, such as skin irritation, itching, or a burning sensation. Copper oxide has proven to be non-irritating, non-sensitising, and safe to use, whether in contact with intact or compromised skin.

First isolated from human plasma in 1973 by Dr. Loren PICKART, the copper peptide or GHK-Cu (INCI: Copper Tripeptide-1) is a combination of three peptides (Glycine-Lysine-Histidine) complexed, with a high affinity, to copper (Cu2+). Already naturally present in the human body, it is notably found in certain bodily fluids (plasma, saliva and urine).

The GHK acts as a carrier, supplying cells with the copper necessary for cellular functions, in a non-toxic form by inhibiting the redox activity of copper by complexing with the tripeptide. Blue in colour, the copper peptides used in cosmetics are of synthetic origin.

What are the skin benefits of copper peptides?

• Activating the wound healing process: GHK-Cu is equipped with various biological actions that accelerate wound healing and skin remodelling: (1) it can activate the production of metalloproteinases and anti-proteinases, thus enabling the removal of damaged proteins from the extracellular matrix; (2) it can stimulate the synthesis of collagen, elastin and glycosaminoglycan by fibroblasts to restore skin integrity; (3) it can support the function of epidermal stem cells by positively regulating the expression of p63 in keratinocytes; (4) it helps to restore blood flow in damaged tissues by stimulating the formation of new blood vessels through the increased production of vascular endothelial growth factors (VEGF).

• Enhancement of Vascularisation: Copper peptides are believed to boost blood circulation around the hair follicles, thereby supplying the scalp with the necessary oxygen and nutrients to promote hair growth and increase hair size.

• Diminishing the visual signs of ageing: Studies on mature skin have shown that copper peptide can help to firm the skin, improve its firmness, density and elasticity, and reduce the appearance of wrinkles, fine lines and photo-damage, by stimulating the production of extracellular matrix macromolecules (collagen, glycosaminoglycans and elastin) and increasing cellular activity.

• Influencing hair growth: in a study, AHK-Cu (L-alanyl-L-histidyl-L-lysine-Cu2+) has shown that it can stimulate the elongation of human hair follicles ex vivo and the proliferation of dermal papilla cells in vitro, which are specialised fibroblasts that play an important role in the morphogenesis and growth of hair follicles. The copper peptides thus have the ability to extend the hair growth cycle, meaning that it takes longer for hair to fall out.

• Protection against free radicals: It has been demonstrated that GHK-Cu increases the level of antioxidant enzymes and the activity of superoxide dismutase, which requires copper metal ions to be active. The copper peptide is also capable of inhibiting lipid peroxidation by modulating iron levels. Thus, the copper-peptide complex is able to effectively neutralise harmful free radicals and their actions on the skin.

• Reducing inflammation: studies have established that copper tripeptide can suppress inflammation by lowering the level of expression of pro-inflammatory cytokines, such as TGF-β, IL-6 and TNF-α in dermal fibroblasts. It is thus suggested that GHK-Cu could be used as a topical agent to soothe irritated skin and inflammatory skin conditions.

• Enhancing hair colour: copper is an essential trace element for the functioning of many metalloenzymes, acting as a co-factor, including the tyrosinase, an enzyme essential for the biosynthesis of melanin responsible for the pigmentation of the skin and hair.

Despite its numerous benefits for the skin, its absorption through the skin remains challenging and low due to its hydrophilic nature. This is why several devices have been developed to facilitate the skin penetration of GHK-Cu.

What are the potential dangers of using copper peptides in cosmetics?

Copper peptides generally do not present major risks. Moreover, when GHK is coupled with copper, the peptide inhibits the redox activity of copper, allowing the administration of copper in a non-toxic form that can then be utilised by cells. However, it has been reported that they can trigger an allergic reaction, causing itching and/or redness.

The copper sulfate (INCI: Copper Sulfate) is an inorganic salt produced by reacting copper oxide with sulfuric acid. It appears as a blue crystalline solid. In its natural state, copper sulfate is found in chalcanthite.

What are the benefits of copper sulfate?

Copper sulphate is primarily used for its ability to kill bacteria and fungi through several mechanisms. The contact with copper ions causes damage at the cellular envelope level. Furthermore, copper also easily catalyses reactions (Fenton and Haber-Weiss) that lead to the production of hydroxyl radicals. These reactive oxygen species induce lipid peroxidation and protein oxidation. Finally, copper ions also target the metabolic enzymes necessary for the normal functioning of microorganisms, leading to their inactivation.

What are the potential dangers of using copper sulfate in cosmetics?

Non-sensitising, the external use of copper sulfate is generally perceived as safe. A few rare examples of allergic dermatitis to copper sulfate have been reported in the literature. In one study, 10,936 patients applied copper sulfate epicutaneously over a 10-year period (1975 - 1985) and 37 (0.34%) of them reacted.