What are the Differences between Hyaluronic Acid of Different Molecular Weights?

This article explains how hyaluronic acid (HA) of different molecular weights functions within skincare. It outlines what molecular weight means, how high, medium, and low weight HA behave differently on the skin, and why selecting the right type is crucial for effective formulation. It also highlights key considerations for brands and manufacturers when choosing HA raw materials, from performance goals to product texture and stability.

What does the Molecular Weight of Hyaluronic Acid Mean?
 

The molecular weight of hyaluronic acid (HA) describes the size of its polymer chains. As a naturally occurring polysaccharide composed of repeating glucuronic acid and N-acetylglucosamine units, HA can vary widely in chain length. These variations result in different molecular weights, typically ranging from several hundred Daltons to over a million Daltons. The molecular weight directly influences HA’s behavior—its ability to bind water, its stability, and how it interacts within cosmetic or dermatological formulations.
 

How Do High, Medium, and Low Molecular Weights Hyaluronic Acid (HA) Perform Differently on the Skin?
 

Different molecular weights lead to distinct skin effects.

High–molecular-weight Hyaluronic Acid (HA) forms a breathable, protective film on the skin’s surface. By reinforcing the skin barrier and reducing transepidermal water loss, it delivers long-lasting surface hydration and helps maintain skin smoothness.

Medium–molecular-weight Hyaluronic Acid (HA) provides balanced hydration. It penetrates slightly deeper than high-MW HA, supporting elasticity and improving the skin’s overall texture. The molecular weight is usually around 800,000 to 1,200,000 Da.

Low–molecular-weight Hyaluronic Acid (HA), with its smaller size, travels into deeper layers such as the epidermis and even the superficial dermis. This deeper hydration contributes to visible plumpness, improved firmness, and supportive anti-aging benefits. For example, Rejuvenating 400Da Sodium Hyaluronate (sodium salt form of Hyaluronic Acid) .
 

Why Is Choosing the Right Molecular Weight Important in Skincare Formulations?
 

Each molecular weight fulfills a different functional role, so selecting the appropriate form is essential for achieving the desired product performance. Formulators often combine multiple molecular weights to create layered hydration. This multi-level approach enhances both immediate and long-term benefits, improving skin comfort, elasticity, and resilience.
 

What Should Brands and Manufacturers Consider When Using Different Molecular Weights?
 

The choice depends on formulation goals, product type, target skin concerns, and regulatory requirements. For instance, serums aiming for intensive hydration may incorporate a blend of low and medium MW HA, while creams or masks focusing on barrier repair may rely more heavily on high MW HA. Stability, viscosity, sensory feel, and cost considerations also influence molecular weight selection.