Hyaluronic Acid: The Gold Standard Humectant in Modern Dermal Science
What Is Hyaluronic Acid?
Hyaluronic acid (HA), or hyaluronan, is a naturally occurring glycosaminoglycan—a large, water-attracting sugar molecule composed of glucosamine and glucuronic acid units. Present in virtually all connective tissues, HA plays a critical role in tissue hydration, cushioning, and cellular communication. Up to 50% of the body's total hyaluronic acid resides in the skin.
HA’s unique properties—biocompatibility, high molecular flexibility, and the ability to bind up to 1,000 times its weight in water—have made it a hero ingredient in modern cosmetic science and a key biomaterial across medical fields.
HA in Human Skin
Location: Found in both the dermis and epidermis
Form: Binds with proteins and other glycosaminoglycans like chondroitin and dermatan sulfate to form hydrated, gel-like networks
Function: Maintains skin hydration, supports barrier function, aids in nutrient transport, and contributes to firmness and elasticity
Aging Impact: HA levels naturally decline with age; by 50, skin HA can drop by ~50%, contributing to wrinkle formation, roughness, and decreased suppleness
Production: Biotech-Grade vs Animal-Derived HA
Today, most cosmetic-grade hyaluronic acid is produced via microbial fermentation using safe strains of non-GMO bacteria such as Streptococcus zooepidemicus. This results in a high-purity, vegan-friendly, and reproducible material. Animal-derived HA (e.g., from rooster combs) is now less common due to cost, sustainability issues, and allergen risks.
Formulation Applications in Cosmetics
Thanks to its water solubility and multifunctionality, HA is featured in nearly every skincare category:
Moisturizers & serums: High- and low-molecular weight HA for layered hydration
Microneedle patches & masks: For targeted delivery and plumping effects
Haircare: For improved scalp hydration and hair fiber flexibility
After-sun & recovery products: Due to HA’s soothing and antioxidant-like activity
Typical formulation inclusion levels: 0.01%–2.0%, depending on molecular weight and format.
Molecular Weight Matters
Type of HAApprox. SizeKey BenefitsBest ForHigh Molecular Weight1,000+ kDaSurface hydration, film-forming, plumpingGels, serums, barrier lotionsLow Molecular Weight50–300 kDaDeep hydration, increased elasticitySerums, anti-aging products, calming productsOligo-HA / Nano HA<50 kDaPenetrates deeper layers, anti-wrinkleAdvanced delivery systems, intensive repair formulations
💡 Formulator Tip: High-MW HA thickens water rapidly—sprinkle slowly with high shear to avoid clumping. Low-MW HA offers excellent absorption but won’t contribute to viscosity.
HA in Injectable Fillers
Beyond topical use, cross-linked or stabilized hyaluronic acid serves as a category-leading dermal filler in aesthetic medicine. Clinical data consistently supports its long-term wrinkle reduction, biocompatibility, and reversibility compared to collagen or synthetic fillers.
Key Takeaways for Formulators
Choose the molecular weight based on desired activity: surface hydration vs deeper penetration
Mind the ratio: blending 2–3 sizes of HA often delivers a superior, multi-depth hydration profile
Watch for pH sensitivity and preservative compatibility, especially when formulating with other actives
Low-MW HA can be used at higher percentages (up to 10%) in water phases of emulsions without affecting viscosity
