Ingredient · Humectant
Hyaluronic Acid
INCI · Sodium Hyaluronate
Related names and forms: Hyaluronic Acid · Hydrolyzed Hyaluronic Acid. This list does not indicate synonyms or exact ingredient matches.
Hyaluronic acid (HA) is a polysaccharide, or long sugar chain, found naturally in skin, the fluid in our eyes and the cartilage in our joints. In cosmetics, it is usually listed as "Sodium Hyaluronate", the salt form of the acid, which works more stably on skin. Its appeal in cosmetics comes from its ability to hold hundreds of times its own weight in water molecules. In practice, this means it can create a noticeable feeling of surface hydration and a temporary impression of plumpness. The number of hyaluronic acid serums in the Turkish market has grown rapidly over the last five years, but the real difference between two products usually goes beyond a "contains hyaluronic acid" label: the combination of molecular weights, other humectants and overall formula balance are the determining factors. Hyaluronic acid is also used as a humectant in hair care. In shampoos, conditioners and masks, it is included to attract moisture to the strands and scalp and is often chosen to support moisture in dry or treated (coloured) hair. Klaris therefore reads it not as a standalone star ingredient, but as a supporting component that provides a hydration foundation for the whole formula.
i. Cosmetic Functions
Frequently Discussed Effects
The following headings summarise areas of effect frequently discussed in the literature; visible results in each area require regular use and a suitable formula.
An Immediate Feeling of Hydration
It holds water molecules to give a noticeable feeling of moisture at the skin surface.
A Plumper, More Supple Appearance
It is often a foundational ingredient in formulas that create a temporary impression of plumpness.
Barrier Support Signals
It appears alongside other humectants in formulas that maintain moisture balance.
Mechanism
What Happens Within the Skin?
The following points summarise mechanisms from dermocosmetic literature in plain English. Klaris presents them as background information to help readers understand the context, not as medical claims.
Step 1
Hygroscopic (Water-Attracting) Structure
The carboxyl and hydroxyl groups in hyaluronic acid form hydrogen bonds with surrounding water molecules. This is the biochemical basis of its ability to hold hundreds of times its own weight in water.
Step 2
Layer Effects by Molecular Weight
The high-molecular-weight form (HMW, >1,000 kDa) forms a film at the skin surface; the low-molecular-weight form (LMW, <50 kDa) provides a feeling of hydration towards the upper layer. Modern formulas combine both for a "multilayer hydration" approach.
Step 3
A Member of the Glycosaminoglycan Family
Hyaluronic acid belongs to the glycosaminoglycan family, also found in the skin's natural filling matrix. Topical application does not directly build this matrix, but creates a feeling of surface hydration and temporary plumpness.
Step 4
CD44 Receptor Interaction (In Vitro)
Scientific studies associate hyaluronic acid with the cell renewal cycle via the keratinocyte CD44 receptor. The size of the topical cosmetic effect is context-dependent and assessed within the whole formula.
Step 5
Barrier Support Signals
Adequate surface hydration is one of the conditions supporting natural skin barrier function. Hyaluronic acid makes a measured contribution to this hydration balance alongside other humectants.
ii. Role in the Formula
How Is It Read on a Label?
Hyaluronic acid can act at different skin layers according to its molecular weight. A low molecular weight corresponds to a feeling beneath the surface, while a high molecular weight forms a film that retains surface moisture. Modern formulas combine the two weights for a "multilayer hydration" approach.
A Closer Look · pH, Stability, Synergy
Hyaluronic acid is generally positioned as a "serum foundation" in formulation, frequently appearing in gels, essences, hydrogen-form serums and light emulsion creams. "Sodium Hyaluronate" is more common than "Hyaluronic Acid" on INCI lists; both are different forms of the same ingredient and work similarly on skin. The salt form (sodium hyaluronate) is generally more stable and can be formulated across a wider pH window. Molecular weight (MW) is the most critical variable in hyaluronic acid formulation. The high-molecular-weight form (HMW, ~1,000 kDa and above) creates a surface film, the mechanism behind an immediate feeling of hydration and smoother-looking skin. The low-molecular-weight form (LMW, below ~50 kDa) has a hydration effect towards the upper layers, while medium molecular weight (MMW) offers a balance between the two approaches. Formulas described as "Multi-MW" or "multiple molecular weights" contain these three weights together. Hyaluronic acid is very flexible in pH terms, working stably across the whole skin-friendly pH window (pH 4.0-7.0). It can therefore readily share a formula with pH-sensitive actives such as vitamin C, niacinamide and AHA/BHA; in terms of synergy, it generally acts as a supporting "buffer" that gives extra attention to the temporary dryness these actives may cause. Containing hyaluronic acid does not mean a product will deliver the same hydration result on everyone's skin. Consider the whole formula together with the instructions for use. Crosslinked hyaluronic acid, the form used in aesthetic filler injections, is not found in topical cosmetics and cannot cross the skin surface. It can be useful not to confuse the effect of topical serums with injectable fillers.
Typical Concentration Range
0.1% - 2% (dependent on molecular weight and form)
Ingredient Family
Humectants
iii. Sensitivity Advisory
A Note on Extra Care in Context
Containing hyaluronic acid does not mean a product will deliver the same hydration result on everyone's skin. Consider the whole formula together with the instructions for use.
A sensitivity advisory is not an instruction for use; where individual health circumstances, pregnancy or known sensitivities are involved, discussing the decision with your doctor may be a more contextual approach.
Common Misconceptions
Frequently Confused Points
Common Belief
Using a hyaluronic acid serum creates a filler effect beneath the skin.
A More Contextual Reading
Topical cosmetic hyaluronic acid does not cross the skin barrier to reach the deep dermis and does not create a filler effect. The form used in filler injections is crosslinked and injected directly at the dermal level. Topical serums provide surface hydration and a temporary impression of plumpness.
Common Belief
The higher the hyaluronic acid concentration, the more effective it is.
A More Contextual Reading
Hyaluronic acid concentrations are mostly 0.1-2%. A higher concentration makes the serum more gel-like but does not provide a noticeable additional skin benefit. Molecular weight diversity and formula context may matter more than concentration.
Common Belief
Hyaluronic acid and vitamin C cannot be used together.
A More Contextual Reading
On the contrary, hyaluronic acid is pH-flexible and frequently shares a formula with low-pH actives such as vitamin C. Most modern serums contain both, making it one of the most common "multi-active" formula approaches in the Turkish market.
Common Belief
Hyaluronic acid always gives positive results on dry skin.
A More Contextual Reading
Containing hyaluronic acid does not mean a product will deliver the same hydration result on everyone's skin. Consider the whole formula together with the instructions for use.
Scientific Basis
Sources and Their Scope
The following headings indicate areas of research; they are not citations of a specific publication or confirmation that every statement on this page has been verified. The links provided should be read with their individual scope in mind.
- International INCI / CosIng Database
- Dermocosmetic Research Publications
- Formulation Chemistry Guides
Source Links
- Database RecordPubChem · Hyaluronic Acid Ingredient Record (CID 24759)
- ReviewCIR (2023) · Hyaluronates Final Assessment
- ReviewPapakonstantinou E et al. (2012): Hyaluronic Acid: A Key Molecule in Skin Aging
Database records provide ingredient identity and registration information; on their own, they do not establish the effect of a finished product or its suitability for a profile. Search links are not specific research papers.
iv. Related Ingredients
Ingredients Often Read Together
v. Humectants Family
Other Ingredients in the Same Family
Explore ingredients in the same functional family to deepen your reading of formulas.
vi. Academy · Related Reading
For a Closer Look
5 Min Read
How to Read an INCI List
What the Latin names on a label mean, how ingredients are ordered and what they can tell you about proportions.
6 Min Read
An Ingredient Guide for Sensitive Skin
Ingredient families that may need extra care when skin is prone to irritation.
7 Min Read
How to Choose a Moisturiser: Ingredients and Texture
Humectants, emollients and occlusives, matching texture to your Identity, and reading a moisturiser's INCI list.
vii. Related Concern Guides
Guides That Include This Ingredient
Klaris · Example Analyses
How Does Hyaluronic Acid Feature
in Your Products?
Explore product examples to see the ingredient list, general assessment and match score that changes with the example profile together.
Masked products and example profiles, not a personal analysis. Profile matching in the app is part of Klaris Premium. The app is currently available in Turkish. An English version is in preparation.