Hyaluronic acid is a sugar-based molecule distributed widely throughout our body. It is important for binding water, cell growth, as well as membrane receptor function and adhesion. It is a very genetically conserved substance.
In the skin, hyaluronic acid is preferentially localized in the deep layer, called the dermis, where the cells are not as tightly packed. In this layer, we can also find collagen and elastin fibers, which provide the skin with its elasticity. As part of the aging process, there is a physiological decrease in hyaluronic acid content. This process can be accelerated, for example by chronic sun exposure.
Hyaluronic acid is one of the main components of the extracellular matrix: a three-dimensional network of extracellular macromolecules like collagen, enzymes (proteins), and other important proteins that provide structural and biochemical support for surrounding cells. Therefore, it is indispensable for the cell’s skeletal structure.
Hyaluronic acid is also able to increase cell motility by activating various cell receptors to promote cell migration during wound healing. This property makes it particularly suitable as a moisturizing substance in aged skin, whether due to a genetic predisposition or due to external factors (1-4).
The positive effects of topically applied hyaluronic acid on dermal connective tissue metabolism and the antioxidant capacity of hyaluronic acid have made the popularity of this substance grow, leading to its increased use in the field of cosmetics.
Recent studies on the daily use of hyaluronic acid creams over the course of three months showed that the depth of perioral and periorbital wrinkles demonstrated a significant decrease of about 10-20% in all groups tested, whereas skin tightness increased significantly in all groups by about 13-30%.
The depth of wrinkles was measured with a computer-assisted surface measurement technique based on optical 3D measuring methods. Skin firmness and elasticity were measured with a cutometer, an instrument that measures physical properties of the skin, such as elasticity (5).
As previously stated, it is important that hyaluronic acid passes the skin barrier to reach the dermis. This is why it has to be formulated in a fragmented form. After fractionation, the low molecular weight allows for easier penetration into the skin. Once it has reached the depth where the collagen and elastin fibers are located, it can bind water, improve skin elasticity, and attenuate skin lines.
As a booster, it can be used as a serum if it is highly concentrated. As part of a daily routine, the serum is appropriate for every skin type. Furthermore, a study showed that the daily topical application of hyaluronic acid may improve seborrheic dermatitis (6), a chronic skin disorder characterized by red, scaly, greasy, itchy, and inflamed skin.
For a more moisturizing effect, such as in the case of skin with a tendency to dry out, a facial cream can be applied. Facial creams are also "moisturizers" because they contain two groups of active ingredients that increase hydration of the most superficial layer of the skin.
These occlusive and moisturizing substances form an evaporation barrier on helping the skin to bind water. In addition, facial creams contain cosmetic preparations called emollients that smooth rough skin surfaces.