Sodium Alginate Powder is a natural, water-soluble polysaccharide extracted primarily from brown seaweed (kelp). It is widely used in cosmetic, skincare, haircare, pharmaceutical, and food formulations as a thickening agent, gelling agent, stabilizer, and film-forming ingredient. It is especially valued for its ability to absorb water, increase viscosity, create smooth gels, and form flexible films on the skin.
Product Name Sodium Alginate
INCI Name Sodium Alginate
CAS Number 9005-38-3
Chemical Type Natural polysaccharide
Source Brown seaweed
Appearance White to pale cream powder
Odour Nearly odourless
Solubility Soluble in water; insoluble in oils
Main Function Thickener, gelling agent, stabilizer, film former
Benefits and Uses in Cosmetics
1. Facial Serums and Hydrating Gels
Sodium Alginate helps create smooth, lightweight, water-based gels. Its film-forming properties help retain moisture at the skin surface and provide a soft, hydrated feel.
2. Peel-Off Facial Masks
One of its most popular cosmetic applications is alginate facial masks. When combined with an appropriate calcium salt, Sodium Alginate forms a gel that can set into a flexible, peelable mask.
3. Anti-Aging Skincare
It forms a temporary tightening film on the skin, helping improve the immediate appearance of smoothness and fine lines. It does not permanently tighten skin or remove wrinkles.
4. Moisturizers and Creams
Acts as a viscosity modifier and stabilizer, improving texture and helping reduce separation in properly formulated emulsions.
5. Hair Care Products
Used in shampoos, conditioners, hair masks, and styling gels to improve viscosity, texture, and film formation.
6. Body Gels and Lotions
Helps create smooth, spreadable textures in body moisturizers, cooling gels, and after-sun products.
7. Encapsulation and Gel Beads
Sodium Alginate reacts with calcium ions to form gel beads, making it useful for encapsulating cosmetic ingredients and creating decorative gel spheres.
Recommended Usage Rates
Cosmetic Application Suggested Starting Level
Facial Serum 0.1–0.5%
Hydrating Gel 0.3–1.5%
Creams and Lotions 0.1–0.5%
Hair Conditioner 0.2–1.0%
Hair Styling Gel 0.5–2.0%
Alginate Peel-Off Mask 10–25% of dry mask powder
Gel Beads / Encapsulation 1–3% in aqueous solution
How to Use Sodium Alginate in Formulations: Disperse Sodium Alginate in glycerin before adding it gradually to the water. Mix until fully hydrated, then incorporate the remaining ingredients. Adjust and verify the final pH and test preservation and stability.
1. Slowly sprinkle Sodium Alginate into water while mixing to prevent clumping.
2. Allow sufficient time for the powder to hydrate completely.
3. Add other water-soluble ingredients as appropriate.
4. Avoid introducing uncontrolled amounts of calcium or other multivalent ions, which may cause premature gel formation.
5. Check the final viscosity, pH, stability, and preservative effectiveness.
Important: Sodium Alginate is not a preservative. Water-based formulations require an appropriate preservation system.
