Misconception: Hyaluronic acid only works on damp skin.

Renowned for its ultra-powerful hydrating properties at low doses, hyaluronic acid is highly favoured in the formulation of a vast number of skincare products, ranging from cleansing milk to care cream , through to lip products and night masks. Its effect? By retaining 1,000 times its weight in water within the cells, this active ingredient helps to maintain the skin's natural hydration levels continuously throughout the day, as well as protecting it from external aggressions that lead to premature ageing, loss of radiance or the appearance of redness.

Already naturally present in the body, hyaluronic acid is an extremely hydrophilic complex sugar composed of D-glucuronic acid and D-N-acetylglucosamine linked together by glycosidic bonds: two sugars that give it the ability to bind water molecules. It notably contributes to the lubrication of joints. In the skin, it fills the spaces between cells, and contributes to hydration and tissue integrity. It also represents one of the essential constituents of the dermis: it forms part of the skin's support mattress along with collagen and elastin.

The hyaluronic acid serum, due to its penetrative power, is among the most popular and effective treatments for improving skin quality on several levels: achieving a smoother and brighter skin texture and restoring bounce to the epidermis. However, to benefit from its properties, certain application advice must be followed.

It is often stated that for it to function and be effective, the hyaluronic acid serum must absolutely be applied to damp skin. Applying it to a dry face could have the opposite effect to that intended and leave the skin more dehydrated. In principle, hyaluronic acid acts like a moisture magnet. Thus, if the skin is dry, it may draw water from the deeper layers of the skin, drying it out. To avoid this phenomenon, one should always ensure that the skin is damp before applying it. As a result, its hydrating powers and effectiveness are amplified by retaining the water provided by the lotion or mist applied beforehand.

In reality, it is not necessary to apply it on damp skin. Firstly, the hyaluronic acid and other humectants do not draw water from the skin like a magnet. They are more likely to "stick" to water molecules through hydrogen bonds and only work over a very short distance. The water must "collide" with the humectant before it binds: it thus acts more like a molecular sponge. Moreover, a serum generally contains up to 80% water, enough for the hyaluronic acid to cling to. Finally, these beliefs have not been scientifically proven.

Thus, regardless of the hyaluronic acid used, they have the same performance, whether applied to wet or dry skin.