The various forms of hyaluronic acid in cosmetics.

Hyaluronic acid is a complex sugar extremely hydrophilic, naturally present in the human body in the joints, muscles, eyes, and especially the skin. Almost 50% of its total amount is housed in the dermis, the deep layer of the skin. It constitutes the extracellular matrix and serves as a support for collagen and elastin fibers. It also ensures skin hydration as it acts like a molecular sponge : it captures water molecules and retains them.

However, over the years,the body's production of hyaluronic acid tends to decrease (a drop of about 6% per decade), which leads to skin sagging, the appearance of the first wrinkles, and a decrease in cellular activity… From the age of 50, it is thus proven that the stock of hyaluronic acid is halved ! In light of this, it is particularly beneficial to provide the skin with hyaluronic acid through dermocosmetic skincare applications. Indeed, this is less invasive and therefore significantly less risky than injections!

Hyaluronic acid comes in several versions, each offering different benefits.

• In its raw form (INCI: Hyaluronic Acid)

  This compound is referred to as high molecular weight (>1,800kDa)). It remains on the surface of the epidermis and creates a protective film that prevents water from evaporating. It also hydrates the superficial layers of the skin and provides a tightening effect.

• In its hydrolyzed form (INCI: Hydrolyzed hyaluronic acid)

  This refers to the hydrolyzed hyaluronic acid derived through an acid, an enzyme, or another hydrolysis method. Hydrolysis allows the fragmentation of hyaluronic acid into smaller size pieces. This process results in what is referred to as intermediate molecular weight (> 1,000-1,800kDa) hyaluronic acid. This is then stored in the skin's connective tissue and prevents water evaporation.

• In its alkaline form (INCI: Sodium Hyaluronate)

  Hyaluronic acid salts are often used due to their high stability and ease of incorporation into cosmetic formulas. They resist oxidation more than other types of hyaluronic acid. Moreover, this form of hyaluronic acid exists at a significantly lower molecular weight than pure hyaluronic acid and hydrolyzed hyaluronic acid. We refer to this as low molecular weight hyaluronic acid (> 50-1000kDa) . This penetrates deeper into the epidermis, reaching the base of the corneal structure, to revitalize the skin. It strengthens and stimulates the production of hyaluronic acid naturally produced by the body. It has a visible effect on reducing wrinkles and plumping the skin. Be aware, hyaluronic acid salts can also exist at high molecular weights, as in our hydrating serum .

• In its cross-linked form (INCI: Sodium Hyaluronate Crosspolymer)

  Low molecular weight hyaluronic acid salts are cross-linked to form a larger molecular weight molecule. This compound is new in skincare. It is interesting because it offers formulators the stability of hyaluronic acid salts and the moisturizing properties of larger molecular weight hyaluronic acids.

• In its acetylated form (INCI: Sodium Acetylated Hyaluronate)

  This form of HA is very recent in the beauty universe.Acetylation is a chemical reaction that allows the replacement of hydroxyl functions -OH of hyaluronic acid with acetyl groups CH₃CO. This form of hyaluronic acid thus possesses both lipophilic and hydrophilicproperties. It has an excellent affinity with the skin and high absorption. Research has shown that this ingredient absorbs three times more water than ordinary hyaluronic acid and ensures prolonged hydration. Moreover, in 2021, researchers highlighted the ability of acetylated hyaluronic acid to inhibit the release of MMP-1, which degrades collagen in mature skin and skin explants exposed to UV and urban dust. Acetylated hyaluronic acid also helped reduce crow's feet and naso-labial foldwrinkles (wrinkles running from the nose to the mouth). This form of hyaluronic acid is therefore particularly promising in combating the signs of aging!

Typology has developed several products containing this potent hydrating agent capable of retaining up to 1,000 times its weight in water.

The following two treatments contain hydrolyzed hyaluronic acid (INCI: Hydrolysed hyaluronic acid):

• The SPF30 face sunscreen prevents photoaging thanks to the combination of mineral and organic filters offering broad spectrum UVA/UVB protection. This protective care is enriched with aloe vera, karanja oil and hyaluronic acid derived from fermented wheat. The clever blend of these three components prevents photoaging, while maintaining skin hydration.

• Available in 5 shades, the tinted lip balm is made up of 99% natural ingredients and notably contains hyaluronic acid derived from wheat fermentation, peppermint macerate, and raspberry seed oil. These ingredients will protect and nourish the skin deeply, while subtly enhancing it thanks to the natural pigments it contains.

The following treatments containlow molecular weight hyaluronic acid, in the form of salts (INCI: Sodium Hyaluronate):

• Combined withaloe vera to deeply and sustainably hydrate the skin, the lotion moisturizing toner helps to regulate the skin's pH after the steps of makeup removal/cleansing, and to eliminate the limestone residues present in the water and deposited on the face, potentially irritating. It helps torehydrate the skin and reduce the sensations of tightness characteristic ofdry skin.

• The hydrating serum is composed of 94% natural-origin ingredients and makes the skin more plump after just a few weeks of use. It contains 3% hyaluronic acid and 2% of provitamin B5 which stimulates the regeneration of dermal and epidermal cells, thereby reducing insensible water loss.

• The nourishing face cream is enriched with lipid-replenishing and moisturizing active ingredients, and is composed of 98% natural origin ingredients. It restores suppleness to the skin and reduces feelings of tightness.

• The moisturizing cleansing milk, composed of 0.5% hyaluronic acid, gently removes all impurities that may have accumulated on the surface of the epidermis, without damaging the skin or weakening the hydrolipidic film. The composition also includes coconut oil andchamomile hydrosol, which nourish and limit discomfort reactions, respectively. It is primarily intended for people with dry to normal skin.

• Hyaluronic acid is combined withcoconut oil in the 9-ingredient facial moisturizer . This minimalist formula hydrates and nourishes the epidermis. Its light and non-greasy texture is suitable for dry, normal, and combination skin, even sensitive ones.

• The hand balm with 10 ingredients is suitable for all skin types, including sensitive skin. This care product with a minimalist formula and enriched with hyaluronic acid combats dryness and potential irritations.

• The hand & nail serum combines hyaluronic acid withplant-based keratin. Ithelps to strengthen the nails and smooth out roughness. To repair your nails, apply a few drops of this serum or incorporate it into your usual hand cream .

• The repairing lip mask forms a protective film on the lips, thereby limiting the evaporation of water and helping to rehydrate and repair damaged lips. Enriched with mango butter (INCI name: Mangifera Indica Seed Butter), this mask melts on the lips and leaves a feeling of softness. Also included in its formula are ceramides (INCI name: Ceramides NG), which have a lipid-replenishing action and hyaluronic acid that is very hydrating.

Discover in more detail our selection of hyaluronic acid-based treatments on our website.

• DINI G.& al. Hyaluronic Acid in Intrinsic Skin Aging.International Journal of Dermatology(1994).

• MICHELOTTI A. & al.Anti-aging and filling effectiveness of six types of hyaluronic acid-based dermo-cosmetic treatments: A double-blind, randomized clinical trial of efficacy and safety.Journal of Cosmetic Dermatology (2014).

• REYNAUD R. & al., The anti-wrinkle properties of sodium acetylated hyaluronate. Journal of Cosmetic Dermatology (2022).