Everyone is talking about hyaluronic acid in cosmetics. But do we really know what it is used for? Hyaluronic acid is found in many of the cosmetics we routinely buy, such as facial serums and creams. It is an ingredient with numerous beneficial properties for the skin, used above all for hydration and volumizing.
Hyaluronic acid (HA) in cosmetics is available in several forms, known as molecular weights, and may come from different sources: its effects also vary according to its composition and origin. In addition, every hyaluronic acid-based product often contains several ingredients that work synergistically to achieve specific effects.
In this article, we explore the benefits of hyaluronic acid for the skin, the different types available, and the characteristics that make it a true must-have for every skin type.
[INDICE:h2]
What is hyaluronic acid?
Hyaluronic acid is a polysaccharide produced directly by the cells in our body. Its name derives from the Greek hualos, meaning “glass” and, by extension, “transparent.” It is found in the eyes, skin, and joints: more precisely, it is a disaccharide biopolymer, and the human body contains approximately 15 grams of it.
It belongs to the group of glycosaminoglycans and consists of a long, unbranched chain created by alternating sugar units of glucuronic acid and N-acetylglucosamine. Thanks to this particular structure, hyaluronic acid can bind and retain numerous water molecules, allowing tissues to remain hydrated.
HA has intrigued many scientists since its discovery in the human eye, precisely because of the breadth of its biological roles despite its chemical simplicity. It was not long before the cosmetics and medical industries decided to reproduce this molecule by combining it with other ingredients. Today, topical hyaluronic acid is a cornerstone of cosmetics designed to hydrate the skin and reduce wrinkle formation.
Aesthetic doctors use it by injecting it directly under the skin as a dermal filler to restore volume to critical areas of the face; it is also used to hydrate and protect the eyes, as a humectant, and in joint injections to support joint health.
In simple terms: hyaluronic acid attracts large quantities of water molecules — up to one thousand times its own weight — and retains them in the skin. This is why it is used to maintain hydration and softness.
As we age, the hyaluronic acid content in our skin decreases, causing the skin to become increasingly dry and less plump. Hyaluronic acid found in cosmetics therefore makes an important contribution by retaining water molecules on the skin’s surface, restoring lost hydration and smoothing fine lines. When we talk about well-hydrated skin, we mean skin rich in water, which naturally tends to lose it through an effect called TEWL, or transepidermal water loss: water evaporates physiologically, and hyaluronic acid acts by slowing the rate of evaporation.
However, an important distinction must be made here, as it changes the outcome. Dry skin lacks lipids, while dehydrated skin lacks water: hyaluronic acid works on the latter, and on dry skin it is not enough on its own unless it is accompanied by a lipid component that retains the water it attracts. The guide to dry or dehydrated skin explains how to understand which of the two situations applies to you, including the test for distinguishing them.
The hyaluronic acid contained in cosmetics is produced through a biotechnological process called biofermentation: the resulting acid is collected, purified, and dehydrated until it forms a powder, which is then added to water to create a gel.
The benefits of hyaluronic acid for the skin
Hyaluronic acid in cosmetics is used to provide several benefits:
- Hydrates the skin: as we age, we naturally lose collagen and hyaluronic acid, and the skin becomes dehydrated more easily. HA-based products help retain moisture even in the deeper layers, keeping the skin smooth, soft, and healthy.
- Helps protect the skin barrier: dry skin may also have a compromised skin barrier, with flaking, blemishes, and roughness. By binding water molecules, hyaluronic acid keeps the skin hydrated and indirectly protects the barrier.
- Fills wrinkles and fine lines: one consequence of increased hydration is precisely the filling in of fine lines. By retaining water, HA can make wrinkles less noticeable. It may also support the production of collagen, the protein that gives skin elasticity and firmness — a protein made, like all proteins, of amino acids.
- Supports skin volume and structure: in cases of facial volume loss, hyaluronic acid helps regenerate skin cells and improve overall texture, including scars left by acne or sunburn.
- Protects against oxidation: HA helps protect the skin from damage caused by free radicals, unstable molecules that contribute to skin aging.
When applied to the skin, hyaluronic acid creates a kind of transparent film that retains water on the surface and slows its evaporation, improving elasticity and softness. To optimize its performance, it is often used in fragmented form so that it can penetrate into the deeper layers of the dermis. The factors that make the difference are therefore the concentration, the product composition, and the molecular weight.
Low-, medium-, and high-molecular-weight hyaluronic acid
When we talk about the molecular weight of hyaluronic acid, we are referring to its mass, measured in daltons (kDa). The length of the polymer chain profoundly influences its physical, chemical, and biological properties.
Generally, low-molecular-weight HA refers to oligomers of approximately 20 monomers and 7.6 kDa; medium-molecular-weight hyaluronic acid ranges from 20 to 30 kDa; high-molecular-weight hyaluronic acid starts at 1,000 kDa and can reach 25,000 kDa, although most commercial products do not exceed 4,000 kDa.
The main differences concern the skin layer in which they act — to help you navigate the epidermis, dermis, and hypodermis, you will find the complete map in the guide to how the skin is structured and how it works:
- High molecular weight (long chain): acts on the skin’s surface, blocking water evaporation and counteracting skin dehydration.
- Medium molecular weight: penetrates the skin, supplying the water needed to preserve firmness and elasticity.
- Low molecular weight (short chain): reaches the deeper layers, helping stimulate collagen. This type has a longer-lasting effect because it helps store moisture in the connective tissue.
Each type supports skin health, whether by establishing a barrier against evaporation or penetrating deeply to revive tone from within. Hyaluronic acid works best when different molecular sizes are used together: only then can it redefine facial contours, help maintain cellular firmness, naturally plump the skin, and restore a more radiant and smooth complexion.
Hyaluronic acid-based cosmetic products
Before purchasing a hyaluronic acid-based cosmetic product, it is important to pay attention to the HA percentage, molecular weight, and source. It is also often listed as sodium hyaluronate, obtained through the reaction between hyaluronic acid and sodium hydroxide.
Since every product is different — serum, mask, or cream — its composition also influences the effects of the hyaluronic acid it contains. Very low concentrations are not very effective, while excessively high concentrations may irritate the skin: for serums, the optimal percentages generally remain around 2%. In some cases, however, it is necessary to consider the overall composition and the purpose of the product, because the synergy between active ingredients may enhance HA’s effects, improve its absorption, or stimulate the production of endogenous hyaluronic acid.
LeLang uses different concentrations of hyaluronic acid in its cosmetics, designed for specific needs and skin types. The Hyaluronic Advance face cream contains a combination of patented hyaluronic acids with different molecular weights.
Macrocystis algae extract: a skin-surface activator
This biotechnology-derived algae ingredient is rich in polysaccharides and low-molecular-weight hyaluronic acid. It is extracted from the algae Macrocystis pyrifera, which can extend more than 60 meters from the seabed in its quest for sunlight. It contains vitamins and trace elements that act on the skin by inhibiting metalloproteinases and helping maintain dermal balance. Polysaccharides and hyaluronic acid work together to create a smooth, even surface layer with a tightening effect, preserving the skin’s natural moisture and minimizing TEWL.
Cross-linked hyaluronic acid: a surface filler effect
Hyaluronic Advance contains a highly pure cross-linked hyaluronic acid: a three-dimensional network polysaccharide that helps visibly reduce facial wrinkles and soften fine lines while improving skin elasticity.
Cross-linked hyaluronic acid is best known for use as an injectable dermal filler, but this type can also be used topically, with a visible plumping effect on the surface.
Low-molecular-weight sodium hyaluronate
This natural, low-molecular-weight sodium hyaluronate has a highly moisturizing effect that improves skin elasticity almost immediately by reducing wrinkle depth. Even at low concentrations, it remains effective thanks to its molecular structure, which creates a thin film on the skin, ensuring smoothness and firmness; in innovative formulations, it also improves the absorption and action of relipidating agents. It has antioxidant and protective properties and helps improve skin tone.
Microalgae exopolysaccharide
This compound of hyaluronic acid, galactose, galacturonic acid, glucose, mannose, and N-acetylglucosamine has an immediate filler effect on the extracellular matrix. Its hyaluronic units bind to hyaluronic acid receptors such as Layilin, with an affinity of over 60%: this is a receptor in the lectin family involved in activating cell regeneration and tissue remodeling processes.
At a biological level, it acts as a collagen booster: the sugars it contains, including glucuronic acid and N-acetylglucosamine, are building blocks of hyaluronic acid, and their presence in the skin supports HA synthesis by fibroblasts.
We always indicate the source of the figures we report: data concerning these patented active ingredients come from the respective manufacturers’ tests. This is standard practice for all ingredients of this type, and knowing where data comes from is part of making an informed choice.
The Hyaluronic Advance face cream is a highly moisturizing and protective product that improves the overall appearance of the skin and wrinkles.
HYALURONIC ADVANCE Anti-Aging Elasticizing Face Cream - Ultra Fill Filler like action Stimulates the production of Endogenous Hyaluroni... Discover HYALURONIC ADVANCE
However, hyaluronic acid is only one way to restore water to the skin: humectants, emollients, and occlusives work on three different levels and should be chosen according to the type of deficiency. Explore the complete selection of LeLang facial moisturizing treatments, from serums to creams, and the criteria to guide your choice in the skin hydration guide.
If you would like to learn more about the role of the other active ingredients that work synergistically with hyaluronic acid, also read our guide to peptides in cosmetics.
Free 15-Minute Consultation with the Founder
Would you like to understand which concentration and molecular weight of hyaluronic acid is best suited to your skin? Book a free virtual skincare consultation with Elisa Avalle, founder of LeLang.
