How does hyaluronic acid take care of your hair?

Hyaluronic acid is the primary ally for dry hair.

Hyaluronic acid is a molecule naturally present in the body, known for its ability to attract and retain water. Depending on its molecular weight, it can hold up to 1,000 times its weight in water. In hair products, hyaluronic acid can be used in a hydrolyzed form to adhere to hair fibers and partially penetrate the cuticle, or in a high molecular weight non-hydrolyzed form to create a protective film on the hair surface. In any case, it can provide several benefits to the hair:

• Hyaluronic acid can support porous hair : As a reminder, the hair porosity depends on cuticle integrity, the hair’s outer protective layer, and its intercellular cement. Mainly composed of ceramides, this cement acts as a semi-permeable barrier that maintains cellular cohesion and limits exchanges with the environment. When damaged, the cuticle becomes uneven, micro-pores form, and the fiber becomes more permeable. Using high-molecular-weight hyaluronic acid on this hair type can help compensate for hair porosity by forming a hygroscopic film on the fiber surface that helps trap water and makes hair more flexible and elastic. For improved efficacy, we recommend combining it with a nourishing treatment rich in ceramides, to fill cuticle gaps.

• Hyaluronic acid can prevent split ends : The split ends result from progressive cuticle degradation, the hair’s external protective layer. When it erodes, the cortex, the inner part rich in fibrillar keratin, is exposed and may break, causing split ends. Applying a hyaluronic acid–based treatment on the lengths may help prevent this. With its film-forming properties, this ingredient forms a hydrating, protective layer on the fiber’s surface, reducing water loss and limiting mechanical, thermal, and environmental stress. By hydrating hair, hyaluronic acid helps preserve fiber flexibility and protects against breakage.

• Hyaluronic acid can tame unruly hair : Unruly hair tends to swell, form frizz, and resist styling in humid conditions. Hyaluronic acid, through its hygroscopic properties, forms a lightweight film around hair, limiting moisture exchange with the environment. By hydrating fibers, it smooths the cuticle surface to reduce frizz.

• Hyaluronic acid can restore shine to hair : Dull hair may indicate cuticle damage. When cuticle scales lift or become disorganized, light does not reflect. By restoring hydration to hair fibers, hyaluronic acid helps smooth cuticle scales and strengthen their cohesion, enhancing light reflection and increasing shine.

• Hyaluronic acid can reshape curls : Curly, frizzy, or coily hair has a more twisted structure than straight hair, making its cuticle more irregular and more prone to dehydration. However, on this hair type, water loss alters curl pattern and bounce. By enhancing hydration of hair fibers, hyaluronic acid helps define curls and restore flexibility to coily, frizzy, or wavy hair.

To date, the effects of hyaluronic acid on hair have not been confirmed by clinical studies. The benefits mentioned above remain hypothetical. They are plausible based on the properties of hyaluronic acid demonstrated in vitro and in vivo on skin.

Note : Some claim hyaluronic acid has the ability to boost hair growth or slow hair loss. However, although injections of hyaluronic acid can have this effect, no study suggests that topical use does.