L'hyaluronic acid is a glycosaminoglycan already present in the dermis, where it forms the matrix in which the fibers of collagen and elastinare embedded. It belongs to the humectant family and is among the most effective known: a single molecule can retain up to one thousand times its own weight in water.
Molecular weight makes the difference.High-molecular-weight chains remain on the surface and form a film that limits water loss, with a smoothing effect noticeable from the first application. Low-molecular-weight chains penetrate the upper layers and deliver hydration deeper down, with results that build over time. The best formulas combine them because the two behaviors work at different levels and together cover the full depth a cosmetic can reach.
It works well for all skin types, including oily skin, because it hydrates without adding lipids: skin can be oily and dehydrated at the same time, and this is more common than you might think. It delivers the best results when applied to still-damp skin and followed by moisturizer, the step that seals in the water drawn to the surface and prolongs its effect throughout the day.
A clarification about the name, which often appears in different contexts: cosmetic hyaluronic acid works on the surface and is reversible, using a mechanism different from that of injectable treatments, which are medical procedures. The plumping effect seen in the mirror comes from water retained in the superficial layers, and lasts as long as the product is used consistently.
On our blog, you can find an in-depth article on how to choose hyaluronic acid based on molecular weight.
