Sodium Stearoyl Glutamate is a highly efficient, plant-derived anionic emulsifier that stabilizes oil-in-water formulations while offering skin-conditioning properties. This amino acid-based surfactant is prized for creating elegant textures and maintaining the skin’s natural barrier without the irritation often associated with traditional surfactants.
- INCI Name:
- Sodium Stearoyl Glutamate
- Chemical/Scientific Name:
- L-Glutamic acid, N-(1-oxooctadecyl)-, monosodium salt
- Common Aliases:
- Monosodium Stearoyl Glutamate, Hydrogenated Tallowoyl Glutamic Acid (historical reference)
| Category: | Emulsifiers |
| Source Origin: | Vegetable-derived (typically from glutamic acid and stearic acid) |
| Comedogenic Rating: | 0 |
| Primary Industries: | Skincare, Sun Care, Baby Care, Color Cosmetics |
| Solubility: | Water-dispersible |
At a Glance: Properties & Effects
| Formula Stability: | |
| Texture Enhancement: | |
| Hydration/Moisture: | |
| Irritation Risk: |
Primary Benefits:
- Excellent emulsification at low concentrations (0.5%–1.5%).
- Supports the formation of lamellar liquid crystal structures.
- Enhances the spreadability and “skin feel” of heavy creams.
- Provides high electrolyte tolerance in complex formulations.
- Maintains skin pH and reduces trans-epidermal water loss (TEWL).
Potential Risks:
- Extremely low risk of sensitization; generally considered non-irritating.
- Requires specific processing temperatures (hot-process) for optimal stability.
Biological Action & Cosmetic Profile
Surface-active properties in this molecule arise from its amphiphilic structure, combining a hydrophilic glutamic acid head group with a lipophilic Stearic Acid tail. Unlike harsh sulfates, this anionic surfactant interacts gently with keratinized cells. Its ability to form lamellar structures is significant because these bilayers mimic the natural lipid organization of the human stratum corneum. By integrating into the skin’s surface layers, the ingredient helps reinforce the moisture barrier rather than stripping it away.
Technological versatility makes this ingredient a staple for modern “clean beauty” formulators. It effectively stabilizes high oil-phase concentrations—even those containing problematic UV filters or silicones—without requiring high levels of co-emulsifiers. Emulsions stabilized with this glutamate derivative typically exhibit a “light” and non-greasy finish, even when using heavy lipids like Butyrospermum Parkii Butter. Furthermore, it is ECOCERT and COSMOS compliant, aligning with global standards for natural and organic cosmetic products.
Broader Applications & Origins
Synthesis of this ingredient involves the acylation of glutamic acid, an amino acid, with fatty acids derived from vegetable oils. Because of its biodegradable nature and low toxicity to aquatic life, it is frequently used in eco-conscious rinse-off and leave-on products. Beyond traditional lotions, it serves as a mild cleansing agent in high-end foaming cleansers, where it provides a dense, creamy lather without disrupting the acid mantle.
Routine Integration
Synergies:
- Fatty Alcohols: Works exceptionally well with Cetearyl Alcohol or Behenyl Alcohol to build viscosity and structural integrity.
- Humectants: Enhances the skin-conditioning effects of Glycerin and Sodium Hyaluronate.
- Emollients: Pairs effectively with Caprylic Capric Triglyceride to create fluid, stable milk-style emulsions.
Conflicts:
- Cationic Ingredients: As an anionic substance, it may occasionally form complexes with certain cationic polymers (e.g., Polyquaternium 10) if the formulation pH is not carefully balanced, though this is rare in standard skincare.
Clinical Consensus & Safety
The Cosmetic Ingredient Review (CIR) Expert Panel concluded in their safety assessment that Sodium Stearoyl Glutamate is safe as used in cosmetic formulations. Clinical data indicates that it is neither a primary irritant nor a sensitizer, even at concentrations significantly higher than those typically found in finished products. Because it is derived from amino acids naturally present in the human body, its biocompatibility profile is excellent. Regulatory bodies including the SCCS and CosIng recognize it as a safe emulsifying and skin-conditioning agent for both leave-on and rinse-off applications.
Is Sodium Stearoyl Glutamate safe for sensitive skin?
Yes. Due to its amino acid base, it is significantly milder than traditional synthetic emulsifiers. It is frequently used in formulations specifically designed for eczematous or hypersensitive skin because it does not disrupt the skin’s lipid barrier.
Is this ingredient vegan and natural?
Generally, yes. Most commercial versions are produced from vegetable-derived fatty acids and corn-derived glutamic acid. It is widely approved by natural certification bodies like COSMOS and ECOCERT.
Does it cause acne or clogged pores?
This ingredient has a comedogenic rating of 0. It is a large molecule that functions primarily as a stabilizer and conditioner on the skin’s surface, making it highly unlikely to penetrate or clog pores.