Silica: in which cosmetic products?

Silica in skincare and sun care.

The silicon dioxide, more commonly known as silica (or silica), is a mineral-derived ingredient widely present in numerous cosmetic products. It is particularly found in skincare, makeup, hair care and exfoliating formulations. Its amorphous (non-crystalline) form is favoured for its diverse functional properties and good skin tolerance.

In facial care and sunscreens, silica acts as a thickening, emulsion-stabilising and absorbing agent. It enables modulation of formula texture, limits the perceived oily phase on application and enhances UV filter stability, particularly in mineral-based sunscreens. A recent study conducted on biogenic silica (spherical structure) particles derived from sugarcane bagasse demonstrated their physicochemical stability, good in vitro tolerance and potential activity in pro-collagen synthesis, suggesting increased cosmetic interest.

Silica in make-up.

In make-up, the silica (silica) is an ingredient used in formulations designed to provide a smooth, matte and natural. It is notably present in loose or compact powders, foundations and make-up bases. Its microporous structure provides excellent lipid absorption, helping to reduce the shiny appearance of seborrhoeic areas throughout the day. By absorbing excess sebum on the skin’s surface, it could help extend make-up wear and maintain a mattified complexion without any greasy effect.

Beyond its absorbent capacity, the silica is also valued for its optical effect known as soft-focus. It can diffuse light uniformly, which visually blurs skin irregularities such as fine lines, enlarged pores or minor imperfections. This property is due to the refraction and reflection of light by spherical silica particles or amorphous. Incorporating silica particles into make-up formulations could also improve the perceived evenness of the complexion and the skin’s softness to the touch.

These effects mattifying, blurring and texturising make it a sought-after ingredient in products for combination to oily skin, which seek to control shine without weighing down make-up textures. The silica also enhances the sensory feel of formulations: it lightens textures, promotes smoother application and prevents the often undesirable cakey effect associated with long-wear make-up.

Silica in hair styling products and hair care treatments.

The silica is also present in many haircare formulations, particularly in dry shampoos and texturising sprays. Its primary function in these products lies in its capacity to efficiently absorb moisture and sebum accumulated on the scalp, thereby prolonging the feeling of clean, lightweight hair without requiring washing with water. This action is enabled by the porous structure and high specific surface area of certain forms of amorphous silica (such as precipitated silica), which can capture oily substances on their surface through physical adsorption.

In dry shampoos, silica particles are sprayed onto the roots of the hair. They act like micro-sponges that absorb excess lipids and moisture, instantly restoring volume and freshness to the hair. Unlike some heavier or opaque absorbent agents (such as starch or clay), silica achieves a mattifying effect without leaving any visible residue, even on dark hair. It is therefore highly valued for its invisible finish and dry touch.

Beyond its absorbent capacity, the silica also plays a texturising role: it increases the hair’s surface roughness, making styling easier and imparting body to the locks. In styling sprays or volumising powders, this effect is particularly sought to structure hairstyles without weighing hair down or making them greasy. Furthermore, the use of silica in hair care has been reinforced by evolving regulations on microplastics. Indeed, since the phased ban on certain non-biodegradable solid plastic particles used as texturising or exfoliating agents, silica has emerged as a more environmentally friendly mineral alternative. Its biodegradability and chemical inertness make it a safe and sustainable option, both for the user and for aquatic ecosystems.

Sources such as the SCCS report confirm that synthetic amorphous silica is considered safe in cosmetic applications, including hair care, in the absence of an inhalable nanoform. This reassures consumers regarding the safety of this ingredient in spray or powder formulations. Thus, silica emerges as an increasingly indispensable technical and eco-friendly ingredient in the realm of modern hair care.

Silica as a mechanical exfoliant in scrubs.

Finally, in scrubs and exfoliating treatments, silica is used in granular or porous form to provide gentle, non-aggressive mechanical exfoliation. The silica particles act by friction on the epidermal surface, helping to detach dead cells from the stratum corneum and promoting their removal during rinsing. This mechanical process stimulates cell renewal and helps refine skin texture, resulting in a more even, luminous and radiant complexion. The size, shape and hardness of the silica particles can be adjusted according to the desired level of exfoliation. Unlike more aggressive abrasives such as crushed fruit pits or sea salts, silica allows precise control of particle size distribution, thereby reducing the risk of micro-injuries to the skin. Certain porous forms of amorphous silica feature a rough yet non-cutting surface, making them particularly suitable for sensitive or redness-prone skin.