Everything you need to know about copper in cosmetics.

Several copper derivatives are present in skincare products. Among the most common, we can mention copper PCA, copper peptides and copper gluconate. Depending on each compound, various benefits are provided to the skin and hair.

• TheCopper PCA(INCI: Copper PCA) is primarily used for itsphysio-seboregulating antibacterial properties. It purifies combination to oily skin and rebalances oily-prone scalps. It also possesses mattifying qualities, hence its recurring presence in complexion formulas.

• Thecopper peptides(INCI: Copper Tripeptide-1) are molecules made up of a sequence of amino acids, which are the building blocks of proteins. They are already present in the human body, particularly in certain bodily fluids (plasma, saliva, urine) in the form of GHK-Cu. They were discovered in 1973 by Dr Loren PICKART who highlighted their activities on wound healing and their anti-inflammatory properties. In the United States, his work led to the formulation of a moisturising gel used as a topical treatment for acute and chronic wounds.

  Today, in skincare, copper peptides are primarily acclaimed for their regenerative properties. Indeed, they stimulate the production of compounds essential for skin firmness and elasticity, such as collagen, elastin, and glycosaminoglycans present in the dermis. Moreover, they are recognised for their antioxidant virtues. By neutralising free radicals, they reduce the damage caused by UV rays such as wrinkles and skin sagging.

  When applied to the scalp, copper peptides have the ability to stimulate hair growth. Indeed, scientific studies have demonstrated their ability to promote the growth of human hair follicles. Biologically, copper peptides work by stimulating the proliferation of dermal papilla cells, specialised fibroblasts that play a significant role in the morphogenesis and growth of hair follicles.

  Furthermore, copper is one of the micronutrients necessary for the production of melanin, the compound responsible for hair colour. Therefore, a treatment enriched with copper peptides, when applied to the lengths, can enhance the natural colour of the hair. A unique aesthetic feature of copper peptides is their powerful royal blue colour, which naturally colours the products that contain them without leaving any trace on the skin!

• The copper gluconate (INCI: Copper Gluconate) is a copper salt composed of a copper cation and a gluconate anion. The role of gluconate is to promote better bioavailability of copper through the epidermis: in other words, it allows the skin to assimilate copper more easily and deeply. The copper gluconate promotes cell regeneration and wound healing.

  Furthermore, copper is found in several enzymatic systems: it is a cofactor of the antioxidant enzyme, superoxide dismutase, as well as a cofactor of the melanin-stimulating enzyme, tyrosinase. Therefore, it has a complexion-enhancing effect and can stimulate tanning. However, it is important to remember that exposure to UV rays is dangerous and should never be done without sun protection.

Generally, copper derivatives are hydrophilic, meaning they are substances soluble in water and aqueous solutions in general. Therefore, they are found in serums, creams, and cleansing gels, but never in oils.

Due to their smoothing and regenerating properties, copper peptides are often incorporated into serums for mature skin or eye contour treatments. Copper PCA, on the other hand, is primarily used for its "sebum-regulating" benefits in cleansing gels intended for combination to oily skin types.

The copper is an element that is very well tolerated by all skin types. Already present in the body, it is easily absorbed by the epidermis and does not cause any side effects. Thus, there is no contraindication to topical use of skincare products containing copper derivatives: they can be used by pregnant and/or breastfeeding women.

Regarding copper peptides, these are typically introduced into cosmetic formulas in very small quantities (which does not limit their biological actions in any way).

Peptides are often identical or analogous to protein fragments already present in the body, which significantly reduces the risk of side effects. They are generally very well tolerated by all skin types and the risks of allergy are extremely low.

However, as with all skincare treatments, we still recommend performing a skin tolerance test before incorporating it into a routine. To do this, apply a small amount of the product in question to the inside of your elbow and wait 24 hours. If you observe any reaction, do not apply peptides to your skin and/or hair.

• BORKOW G. Using copper to improve the well-being of the skin. Current Chemistry & Biology (2014).

• KIM K. H. & al. The effect of tripeptide-copper complex on human hair growth in vitro. Archives of Pharmacial Research (2007).