Ingredient Spotlights
Hyaluronic Acid: Choosing the Right Molecular Weight
Dr. Sarah ChenMarch 25, 20246 min read
Hyaluronic acid (HA) is one of the most popular cosmetic actives — and one of the most misunderstood. The term covers a spectrum of molecular weights, each with distinct properties.
High-Molecular Weight HA (>1000 kDa)
Sits on the skin surface, forming a moisture-retaining film. Creates immediate plumping and smoothing. Does not penetrate the stratum corneum.
Low-Molecular Weight HA (10–100 kDa)
Penetrates deeper into the epidermis. Longer-lasting hydration. Can cause transient inflammation at very low MW (<10 kDa) in sensitive skin.
Formulation Tips
Combine HMW and LMW HA (0.05–0.2% each) for a multi-depth hydration effect. Dissolve in warm distilled water before adding to your formula.