What does hydrolysed mean here?

The long HA chains have been broken into shorter, lower-molecular-weight fragments, which penetrate further into the epidermis than high-molecular-weight HA.

Is low-molecular-weight HA better?

It goes deeper, but that describes mechanism rather than a separately proven advantage. Published evidence covers hydration and fine dehydration lines across molecular weights.

Why do products list several types of HA?

Combining multiple molecular weights lets a formula hydrate at more than one depth at once — a common and defensible strategy.

What is HA crosspolymer?

A chemically cross-linked, larger HA structure designed for extended-release surface hydration and improved formulation stability.

How much should a product contain?

Commonly 0.1%–2% total HA content. Beyond that there is no proportional gain, and high levels can feel tacky.

Hydrolyzed Hyaluronic Acid — Ingredient Guide

How it works

Hydrolysed hyaluronic acid is HA whose long polysaccharide chains have been broken down into shorter, lower-molecular-weight fragments. That matters because molecular weight is what determines where HA acts. High-molecular-weight HA sits on the skin surface, forming an occlusive, hydrating film. Low-molecular-weight or hydrolysed HA can penetrate more deeply into the epidermis. A third variant, HA crosspolymer, is chemically cross-linked into a larger structure for extended-release surface hydration and better formulation stability. Underneath these differences the core behaviour is identical: HA is a glycosaminoglycan and a powerful humectant, capable of binding many times its own weight in water and drawing it into the stratum corneum.

The evidence

Well-established clinical evidence supports topical HA, across molecular weights, for measurably increasing skin hydration and reducing the appearance of fine dehydration lines in the short term. It is worth being precise about what deeper penetration does and does not mean: it describes where the molecule goes, not a separately demonstrated clinical advantage. HA's endogenous signalling roles through CD44 and other receptors are real but more relevant to injectable and dermal contexts than to a topical serum. The common and defensible formulation strategy is to combine several molecular weights so a product hydrates at multiple depths at once.

Suitability

Suitable for all skin types including oily and acne-prone, since HA hydrates without adding oil. Cosmetic-grade material is produced by bacterial fermentation rather than animal extraction, making it vegan-compatible.

Concentration

Formulas commonly use 0.1%–2% total HA content across all weights combined; higher levels do not confer proportionally more benefit and can feel tacky.

Conflicts & combinations

Broadly compatible with all actives. Apply to damp skin and seal with an occlusive, particularly in low-humidity air, where an unsealed humectant can draw moisture from deeper layers toward the surface.