Comparing Types of Hyaluronic Acid

Hyaluronic Acid (HA)

We talked about the many benefits of hyaluronic acid, you can read about it here. Not all hyaluronic acid is the same. Learn the difference between high, low, and ultra-low molecular weight HA and how to choose the best one for your skincare formulation. Here we are comparing the types of hyaluronic acid.

Hyaluronic Acid is measured in Daltons

Daltons (Da) are a unit of measurement used to express the molecular weight (or mass) of atoms and molecules. In skincare and cosmetic science, Daltons help us understand how large or small an ingredient molecule is—and therefore how deeply it can penetrate the skin.

What is a Dalton?

1 Dalton (Da) = 1 atomic mass unit (amu) = approximately 1.66 x 10⁻²⁴ grams
Named after John Dalton, a 19th-century chemist who developed atomic theory.
Used to describe the mass of proteins, peptides, and polymers—including Hyaluronic Acid.

Why Daltons Matter in Skincare:

The size of a molecule affects how far it can go into the skin:

Molecular Weight (in Daltons)	Approximate Skin Behavior
<500 Da	Can penetrate the skin barrier (Stratum Corneum)
500–1,000 Da	May penetrate somewhat, depending on structure
>1,000 Da	Usually stays on the surface of the skin

This is often referred to as the “500 Dalton Rule”, which suggests molecules larger than 500 Da typically cannot penetrate the skin barrier.

In the Case of Hyaluronic Acid:

HMW HA (1,000,000+ Da): Too large to enter the skin → forms a hydrating film on the surface.
ULMW HA (<6,000 Da): Very small → can penetrate deeply into the skin, reaching lower layers of the epidermis or dermis, potentially offering anti-aging and firming effects.

Comparison of Hyaluronic Acid Types by Molecular Weight

Type	Molecular Weight (Daltons)	Penetration Depth	Hydration	Skin Benefits	Notes
ULMW HA	<6,000	Deepest penetration (dermis)	Low water retention	May reduce inflammation, boost elasticity	May cause irritation in sensitive skin due to deep penetration
SLMW HA	<50,000	Deep penetration (epidermis)	Moderate	Improves elasticity, reduces wrinkles, hydrating at deeper levels	May trigger sensitivity in compromised skin
ELMW HA	80,000–110,000	Deeper layers of epidermis	Balanced	Plumps skin, reduces fine lines	Good skin compatibility
LMW HA	800,000–1,000,000	Mid to lower epidermis	Good hydration	Promotes smoother, more elastic skin	Often used in serums for radiant aging
HMW HA	1,000,000–1,500,000	Surface level (stratum corneum)	Excellent moisture retention	Forms a protective, hydrating film	Soothes and protects barrier, ideal for dry/sensitive skin
Olea HA	Proprietary HA from olive oil, amphiphilic	Dual-action: surface + penetration	High	Deep hydration and barrier support, enhanced skin delivery	Combines benefits of hydrophilic and lipophilic systems, stable and gentle

Formulating Notes & Tips on Usage

HMW HA: Best for hydration and skin barrier support, especially in creams and gels. This is the only hyaluronic acid that creates a gel. Use it at 1% to make a gel.
LMW/ELMW HA: Ideal for radiant-aging serums and deeper hydration without overstimulating.
ULMW/SLMW HA: Great for firming, elasticity, and deep hydration, but use with caution for very sensitive or compromised skin.
Olea HA: Innovative amphiphilic (water + oil-loving) olive-derived HA that offers deeper skin absorption, improved stability, and eco-cert compatibility. Use in waterless, anhydrous formulations.

INCI Names for Various Hyaluronic Acid Types

HA Type	Molecular Weight	INCI Name	Notes
ULMW HA	<6,000 Da	Hyaluronic Acid	Very small fragments; deeper skin penetration
SLMW HA	<50,000 Da	Hyaluronic Acid	Still small; penetrates well
ELMW HA	80,000–110,000 Da	Hyaluronic Acid or Sodium Hyaluronate	Depends on manufacturer’s classification
LMW HA	800,000–1,000,000 Da	Sodium Hyaluronate	Most commonly used in serums
HMW HA	1,000,000–1,500,000 Da	Sodium Hyaluronate	High viscosity; forms surface film
Olea HA	Proprietary, olive-derived amphiphilic	Sodium Hyaluronate Oleate	Lipophilic version, offers both penetration and film-forming