the different types of hyaluronic acid in skincare.

Hyaluronic acid is an extremely hydrophilic complex sugar, naturally present in the human body in the joints, muscles, eyes and especially in the skin. Nearly 50% of its total quantity is found 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 the hydration of the skin because it acts like a molecular sponge: it captures water molecules and retains them.

Nevertheless, as the years go by, the body's production of hyaluronic acid tends to decrease (a drop of about 6% per decade), which leads to skin slackening, the appearance of the first wrinkles and a decrease in cellular activity. From the age of 50, it has been proven that the stock of hyaluronic acid is divided by two. Faced with this observation, it is particularly interesting to provide the skin with hyaluronic acid via dermocosmetic application. Indeed, this is less invasive and therefore much less risky than injections!

Hyaluronic acid comes in several versions, each providing different benefits for your skin.

• In its raw form (INCI: Hyaluronic acid).

  This compound is said to have a 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 moisturizes the surface layers of the skin and provides a tightening effect.

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

  This is the hydrolysate of hyaluronic acid derived by an acid, enzyme or other hydrolysis method. Hydrolysis allows the hyaluronic acid to be split into smaller fragments. It is thus possible to recover a hyaluronic acid of intermediate molecular weight (> 1,000–1,800kDa). This is then stored in the connective tissue of the skin and prevents water evaporation.

• In its alkaline form (INCI: Sodium Hyaluronate).

  The salts of hyaluronic acid are often used because of their great stability and their ease of incorporation in cosmetic formulas. They are more resistant to oxidation 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. It is called low molecular weight hyaluronic acid (> 100–1000kDa). The latter penetrates deeper into the epidermis, to the base of the corneal structure, to revitalize the skin. It reinforces and stimulates the production of hyaluronic acid naturally produced by the body. It has a visible effect on the reduction of wrinkles and plumps the skin. Attention, the salts of hyaluronic acid can also exist with high molecular weight, like in our hydrating serum.

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

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

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

  This form of HA is very recent in the beauty world. Acetylation is a chemical reaction that replaces hydroxyl (OH) functions in hyaluronic acid with acetyl CH₃CO groups. This form of hyaluronic acid thus has both lipophilic and hydrophilic properties. It has excellent affinity with the skin and high absorption. Research has shown that this ingredient absorbs three times more water than ordinary hyaluronic acid and guarantees prolonged hydration. In addition, in 2021, researchers demonstrated 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 light and urban dust. Acetylated hyaluronic acid has also been shown to reduce crow's feet and nasolabial fold wrinkles (wrinkles running from the nose to the mouth). This form of hyaluronic acid is therefore particularly promising in the fight against the signs of aging.

Typology has developed several products containing this powerful moisturizing active ingredient capable of retaining up to 1,000 times its weight in water.

The following two products contain hydrolyzed hyaluronic acid (INCI: Hydrolyzed hyaluronic acid):

• The SPF30 sunscreen prevents photoaging thanks to a 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 from fermented wheat. The clever blend of these three components prevents photoaging, while retaining the skin's moisture.

• Available in 5 colors, the tinted lip balm is made of 99% natural ingredients and contains hyaluronic acid from wheat fermentation, peppermint macerate and raspberry seed oil. These ingredients will protect and nourish the skin depth, while subtly beautifying them with the natural pigments it contains.

The following products contain low molecular weight hyaluronic acid in the form of salts (INCI: Sodium Hyaluronate):

• Combined with aloe vera to deeply and durably moisturize the skin, the moisturizing toner helps regulate the pH of the skin after the make-up removal/cleaning steps, and eliminates potentially irritating lime residue present in the water and deposited on the face. It helps to rehydrate the skin and reduce feelings of tightness specific to dry skin.

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

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

• The hydrating cleansing milk, made up of 0.5% of hyaluronic acid, makes it possible to gently eliminate all the impurities which could have accumulated on the surface of the skin, without attacking the skin nor to weaken the hydrolipidic film. One also finds in the composition of the oil of coconut and the hydrosol of chamomile, which will nourish and limit the reactions of discomfort, respectively. It is addressed mainly to the people having dry skin to normal.

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

• The 10-ingredient hand balm is suitable for all skin types, including sensitive skin. This minimalist formula, enriched with hyaluronic acid, combats dryness and irritation.

• The hands & nails serum associates hyaluronic acid with vegetable keratin. It strengthens the nails and smoothes the roughness. To repair your nails, apply a few drops of this serum or add it to your usual hand cream.

• The vegan plumping lip serum is formulated without mineral oils, beeswax and pigments. It is suitable for normal lips as well as dry or very dry lips. It offers an overall plumping and smoothing action on the lips and lip contour. The lips are moisturized and softened, and the lip contour is smoother and better defined. In addition to low molecular weight hyaluronic acid (200–400 KDa), it also contains a tripeptide (INCI: Palmitoyl Tripeptide-38) which activates the synthesis of elastin and collagen, for plumped and shapely lips.

Discover our selection of hyaluronic acid skincare products in more detail on our website.

• DINI G. & al. Hyaluronic acid in cutaneous intrinsic aging. International Journal of Dermatology (1994).

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

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