Hyaluronic Acid: How Does This Skincare Superstar Actually Work?

Some serums cost $6, others $15 or even $30… but they often share one famous ingredient: hyaluronic acid.

This ingredient has become one of the biggest skincare trends of the last decade. You can find it in countless moisturizers, masks, and serums, but how much do we really know about how it works?

Behind the marketing claims, hyaluronic acid is a fascinating molecule with unique properties that make it one of the most widely used ingredients in cosmetic formulation.

In this article, we will explore how hyaluronic acid works, the different types available, and how to use it correctly when creating your own cosmetics.

Despite its name, hyaluronic acid is not an exfoliating acid like glycolic acid or salicylic acid.

It is actually a polysaccharide naturally found in the human body, especially in the skin, connective tissues, and joints.

Its main characteristic is its incredible ability to bind and retain water.

This is why it has become a key ingredient in skincare products designed to improve hydration, skin comfort, and the appearance of fine lines caused by dehydration.

Depending on the size of the molecules, hyaluronic acid can interact differently with the skin. Cosmetic ingredients are often classified according to their molecular weight, which influences their properties and their role in a formulation.

High Molecular Weight Hyaluronic Acid :

High molecular weight hyaluronic acid, often found as sodium hyaluronate, contains larger molecular chains.

Because of its size, it mainly remains on the skin's surface where it can:

• Create a breathable protective film.
• Reduce water loss from the skin.
• Improve softness and skin flexibility.
• Provide a smooth and comfortable skin feel.

It acts like a moisture-locking layer that helps maintain hydration.

Hydrolyzed or Low Molecular Weight Hyaluronic Acid :

Hydrolyzed hyaluronic acid contains smaller molecular fragments.

These smaller molecules are commonly used in cosmetic formulations to provide a plumping and smoothing effect by interacting with the superficial layers of the skin.

This is one reason why many anti-aging and hydration products include multiple types of hyaluronic acid in the same formula.

Hyaluronic acid is a hydrophilic ingredient, meaning it naturally interacts with water.

For this reason, it should be incorporated into the aqueous phase of a formulation, such as:

• Distilled water.
• Floral hydrosols.
• Water-based cosmetic serums.

When properly dispersed, it creates a slightly gel-like texture that gives formulas a smooth and pleasant skin feel.

Hyaluronic acid is a highly effective active ingredient, and only a small amount is needed.

In DIY cosmetic formulations, it is generally used between:

0.1% and 0.5%

Using more does not necessarily mean better results.

An excessive amount can create a thick, sticky gel texture that feels unpleasant on the skin and makes the product difficult to apply.

Hyaluronic acid is sensitive to formulation conditions.

High temperatures can affect its structure and reduce its performance.

For this reason, it is recommended to add it during the cooling phase of a formulation or at room temperature whenever possible.

Because hyaluronic acid is a polymer, aggressive or prolonged high-speed mixing can damage its molecular structure.

Gentle and progressive mixing helps preserve the quality of the ingredient and ensures a better final texture.