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ingredientsExpert Opinion1 min read
Hyaluronic acid: a key molecule in skin aging
Authors · Papakonstantinou E, Roth M, Karakiulakis G
Journal · Dermato-Endocrinology · July 2012
DOI · 10.4161/derm.21923
What this means for you
The plain-language read
Hyaluronic acid (HA) is the major glycosaminoglycan of the skin extracellular matrix. With age, HA content decreases, contributing to dehydration and loss of elasticity. Topical HA at multiple molecular weights penetrates differentially: high-MW HA forms a hydrating film on the surface; low-MW HA penetrates the epidermis and stimulates endogenous synthesis.
Key findings
- HA content declines significantly with age
- Molecular weight determines depth of action
- Polyglutamic acid holds 4x more water than HA per molecule
- HA must be applied to damp skin to function as humectant, not desiccant
Practical note
Apply HA serum to damp skin and seal with an occlusive (squalane, ceramide cream). In low-humidity environments (sub 50% RH), HA can pull water from the skin if not sealed — context-dependent ingredient.
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What this means for your routine
hyaluronic acidAM/PM routine
If you're targeting dryness, this research supports adding hyaluronic acid to your AM/PM routine.
polyglutamic acidAM/PM routine
If you're targeting dryness, this research supports adding polyglutamic acid to your AM/PM routine.
Translated from this study's findings, not a personal prescription. Pair with your existing protocol and your practitioner's guidance.
Technical Summary, For Professional Reference
Clinical context
HA is the dominant skin GAG and decreases markedly with age. Multiple molecular weights serve distinct functions: HMW HA (>1MDa) provides surface hydration and substantivity; LMW HA (<50kDa) penetrates epidermis and may stimulate endogenous HA synthesis. Crosslinked HA injection remains best-evidence for volumetric correction.
Ingredients discussed
Full abstract→
Hyaluronic acid (HA) is the major glycosaminoglycan of the skin extracellular matrix. With age, HA content decreases, contributing to dehydration and loss of elasticity. Topical HA at multiple molecular weights penetrates differentially: high-MW HA forms a hydrating film on the surface; low-MW HA penetrates the epidermis and stimulates endogenous synthesis. Crosslinked HA injection remains the gold standard for volumetric correction.
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