Yellow Clay: What is its effectiveness on acne-prone skin?

Acne is an inflammatory skin condition, primarily characterised by the appearance of open comedones (blackheads) or closed comedones (whiteheads) on the body. The most affected areas are the face, back and chest. Here are the main factors contributing to the development of acne.

• Excessive sebum production : Sebum is a necessary component for maintaining skin hydration and protection. However, overproduction can lead to the obstruction of skin pores and the emergence of blemishes. This phenomenon can be due to an increase in androgen levels, particularly during adolescence or pregnancy.

• Follicular hyperkeratosis : The epidermis of acne-prone skin does not exfoliate as well as it should, leading to an accumulation of dead cells on the skin's surface that can also clog the pores. Hyperkeratosis indeed forms a keratinous plug that hinders the normal flow of sebum.

• Bacterial colonisation : the bacterium Cutibacterium acnes, a Gram-positive type, thrives in sebum-rich environments. It functions by digesting the triglycerides found in this substance. This leads to the production of free fatty acids that exacerbate the inflammation of the sebaceous glands.

If you are suffering from severe acne, it is necessary to consult a dermatologist who can prescribe you a suitable treatment.

When suffering from mild to moderate acne, yellow clay can be a helpful ally in alleviating symptoms. Like most clays, it is an ingredient with strong absorbent and adsorbent properties, enabling it to combat excess sebum. It thus helps to unclog skin pores and cleanse the skin. It is important to distinguish between absorption and adsorption as these are different physical processes, both responsible for the matifying properties of yellow clay.

Absorption refers to the internalisation of a liquid or a gas. A typical example is that of a sponge soaking up liquid. Yellow clay, for instance, is capable of absorbing excess sebum on the skin. Therefore, it has a matifying effect.

Adsorption refers to the phenomenon of molecules attaching to a surface. The ionic composition and crystalline structure of clay make it negatively charged internally and positively charged on the surface. This charge difference is the basis of its adsorptive power, whether it's on viruses, bacteria... including Cutibacterium acnes.

Studies have indeed highlighted that this microorganism tends to adhere to yellow clay. Therefore, the application of a skincare product enriched with yellow clay helps to eliminate this bacteria, which is partly responsible for acne.

Furthermore, yellow clay has the ability to stimulate cellular renewal. Indeed, this natural ingredient promotes the removal of dead cells on the skin's surface before they cluster and clog the skin's pores.

• 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).