Are there any side effects to using copper in cosmetics?

The copper is a chemical element naturally present in small amounts in the human body. Classified among the trace elements, it plays a crucial role in the formation of collagen, an essential protein of the extracellular matrix that contributes to the structure of the skin. Furthermore, copper possesses antioxidant properties that enable it to protect tissues and cells from damage caused by free radicals.

Certain forms of copper, such as copper PCA, gluconate of copper and peptides of copper, are incorporated into cosmetic care due to their benefits for the skin. Copper PCA is favoured for its antibacterial and sebum-regulating virtues that allow it to purify combination to oily skin and balance greasy scalps. Copper gluconate, on the other hand, promotes cellular regeneration and wound healing. Finally, copper peptides are renowned for their regenerative properties and their ability to stimulate the production of collagen and elastin, two essential proteins for the suppleness and elasticity of the skin. Moreover, the copper peptides provide a beneficial antioxidant action to counteract the signs of skin ageing.

Copper is an element well tolerated by all skin types. Already present in the body, it is easily absorbed by the epidermis and does not cause side effects when used within concentration limits. This limit is set at 1% in cosmetics by the European cosmetic regulation based on Regulation (EC) No 1223/2009. Under these conditions, there is no contraindication to topical use of skincare products containing copper derivatives: they can be used by pregnant and/or breastfeeding women.

However, as with all skincare treatments, we advise you to carry out a tolerance test before incorporating a product containing copper into your routine. To do this, apply a small amount of the product to a part of your face, the crook of your elbow, or behind your ear. If you observe no redness, irritation or itching after 48 hours, it indicates that the product does not cause a hypersensitivity reaction in you.

Note : It is advised against using copper in synergy with exfoliating acids such as AHAs, like glycolic acid, or BHAs, like salicylic acid. It has been observed that these combinations can lead to irritations, even though the mechanism at work has not been elucidated.

• Règlement (CE) No 1223/2009 du Parlement Européen et du Conseil.

• BOROWSKA S. & al. Metals in cosmetics: implications for human health. Journal of Applied Toxicology (2015).