Is hyaluronic acid comedogenic?

Discovered in 1934 by Karl MEYER and John PALMERER, hyaluronic acid is a molecule that forms part of the skin's extracellular matrix. It indeed serves as a support for collagen and elastin fibres, proteins that ensure the skin's firmness and flexibility. Hyaluronic acid also has moisturising properties and can retain up to 1000 times its weight in water. Moreover, this active ingredient has healing and soothing virtues, explaining its popularity in the cosmetic sphere. Finally, it's good to know that hyaluronic acid exists in several forms, with different molecular weights: low molecular weight (50 - 1000 kDa), intermediate molecular weight (1000 - 1800 kDa) and high molecular weight (> 1800 kDa).

If hyaluronic acid is undoubtedly a very good active ingredient for people with dehydrated skin or sensitive skin, what about those with oily or acne-prone skin? In other words, is it comedogenic? The answer is no, hyaluronic acid is not comedogenic, meaning that its application does not cause breakouts. This applies to both low molecular weight and high molecular weight forms, the latter sometimes accused of giving a thick texture to skincare products and causing them to pill. It should be noted that the comedogenicity of an active or cosmetic ingredient is evaluated on a scale of 0 to 5, according to a classification established in 1983 by Dr. MORRIS and his team. A score of 0 means that the ingredient is non-comedogenic and a score of 5 indicates a highly comedogenic effect. The comedogenicity index of hyaluronic acid is 0.

Biocompatible with the skin, hyaluronic acid is a hydrophilic molecule, meaning it retains water on the surface of the epidermis and within skin cells. However, it does not have an affinity with sebum, a rather oily substance, and does not block its flow through the skin's pores, unlike comedogenic ingredients. Indeed, by preventing the evacuation of sebum, these ingredients confine it within the hair follicles until it forms a plug that turns into a blemish. This is not the case with hyaluronic acid.

Key Takeaway : Hyaluronic acid is a non-comedogenic active ingredient suitable for all skin types, including oily skin which, contrary to popular belief, also requires hydration.