Yellow Clay: What are its properties for the skin?

Yellow clay is an aluminium silicate known for its mineral richness. There are several types of clay, such as yellow, green, white or pink clay. Besides their different colours, they are distinguished from each other by their composition. Yellow clay is primarily composed of silica but also contains aluminium, iron, magnesium and calcium.

The use of clay dates back to antiquity. Primarily used in pottery, it also held its place in the therapeutic, cosmetic, and agricultural fields, where it was notably used to repel certain vine parasites. It also possesses interesting properties for the skin and can be used by people with sensitive skin. Moreover, yellow clay is highly appreciated by those with combination to oily or mature skin.

Yellow clay is an ingredient with absorbent and adsorbent capabilities that enable it to combat excess sebum. It thus helps to unclog the skin's pores and "purify" it from certain microorganisms. Yellow clay works by absorbing excess sebum produced by the sebaceous glands, like a sponge, which can potentially lead to the emergence of blemishes (absorption).

Furthermore, its ionic composition and crystalline structure make it negatively charged on the inside and positively charged on the surface. This charge difference allows it to attract and bind to its surface (adsorption) certain bacteria such as Cutibacterium acnes, which is responsible for acne. Therefore, the application of a skincare product enriched with yellow clay helps to cleanse the skin and make it less oily.

If yellow clay is so well integrated into both cosmetic and therapeutic care, it's due to its healing effects on minor wounds. Indeed, this ingredient contributes to theepithelialisation of tissues and accelerates this process. It acts by stimulating the synthesis of collagen and elastin fibres. This is due to the presence of copper in the composition of yellow clay. This metal ensures the proper functioning of lysyl oxidase, an enzyme that catalyses the formation of aldehydes from lysines. The aldehydes produced during this reaction are reactive and assemble together, which causes the cross-linking of collagen and elastin fibres, a process essential for their stabilisation.

Yellow clay is often regarded as an ingredient capable of preventing skin sagging, due to its antioxidant properties. These effects are derived from the metals it contains, notably iron and copper. These are indeed necessary for the activity of superoxide dismutase enzymes (SOD). SODs are metalloproteins that catalyse the degradation of certain free radicals. These molecules are reactive species that damage cells and tissues and promote skin ageing. However, for SODs to be functional, they require metallic cofactors, such as copper and iron. Yellow clay thus helps to neutralise free radicals before they weaken the structure of the extracellular matrix and thereby prevents the appearance of wrinkles.

There are reasons to believe that yellow clay helps to reduce established wrinkles as this ingredient promotes the synthesis of elastin and collagen by fibroblasts, according to the mechanism previously described involving lysyl oxidase. However, no scientific study has so far highlighted the firming property of yellow clay, so caution is advised.

Affecting all skin types, the lack of radiance is often exacerbated by a lack of sleep, pollution or a deficient diet. However, this dull effect can be mitigated by incorporating antioxidants into skincare products.

Our antioxidant mask with yellow clay (INCI: Kaolin), turmeric (INCI: Curcuma Longa Root Extract) and lemon verbena floral water (INCI: Lippia Citriodora Leaf Water) is an essential ally for restoring the radiance of your complexion. The synergy of these ingredients revitalises the epidermis and protects it from the effects of oxidative stress, by neutralising free radicals.

• CARRETERO M. Clay minerals and their beneficial effects upon human health: a review. Applied Clay Science (2002).

• Thèse de François HERNOT. L’argile, son utilisation à l’officine (2016).

• FRERICH B. & al. Silicon-dioxide-polyvinylpyrrolidone as a wound dressing for skin defects in a murine model. Journal of Cranio-Maxillo-Facial Durgery (2017).