Best For Skin Types
All, Dry, Sensitive, Mature
Addresses
Usage Frequency
Daily
What Is Sodium Polyaspartate?
Sodium polyaspartate is a synthetic polymer derived from the amino acid aspartic acid. It's a water-soluble ingredient that functions as both a humectant and conditioning agent in skincare and haircare formulations.
In topical products, it works by forming a film on the skin or hair surface and drawing moisture from the environment and deeper skin layers, helping to maintain hydration and improve texture.
How It Works
Sodium polyaspartate is a humectant, meaning it has a chemical structure that attracts and binds water molecules. When applied to skin, it draws moisture from the air and from deeper layers of the epidermis, then holds this moisture at the skin surface.
The polymer also forms a light conditioning film that smooths the skin's surface, improving feel and appearance without leaving a heavy or occlusive residue.
Clinical Evidence & References
Research specifically on sodium polyaspartate in skincare is limited, though the ingredient has a long history of use in cosmetics. Its humectant properties are consistent with other polyaspartate-based polymers studied in dermatological contexts.
Available data suggests it is well-tolerated and effective as a hydrating and conditioning agent, though robust clinical trials comparing it directly to other humectants in skincare are scarce. It is generally recognised as safe for topical use.
How to Use
Sodium polyaspartate is typically used as a supporting ingredient in hydrating serums, moisturisers, and conditioning treatments rather than a primary active. For best results, apply to damp skin as part of your routine so it can draw moisture into the skin. It works well in layered routines and pairs effectively with occlusive ingredients like oils or butters to seal in hydration.
Safety & Precautions
Frequently Asked Questions
From the Clinic
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Sodium Hyaluronate Dimethylsilanol
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Sodium Mannose Phosphate
A phosphate-based humectant that draws moisture into the skin
Sodium PCA
Sodium PCA is the sodium salt of PCA (pyrrolidone
Sodium Polyglutamate
Humectant that provides long-lasting hydration | Hydrating efficacy rivals (some studies show it surpasses) hyaluronic acid
Sodium Retinoyl Hyaluronate
A stabilised retinoid derivative that combines vitamin A activity with hydration
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Tomato fruit extract with antioxidant properties and potential skin-conditioning benefits
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