What Is Sodium Stearyl Dimethyl Glycine?
Sodium Stearyl Dimethyl Glycine is a synthetic ingredient made by reacting stearic acid, a fatty acid often sourced from plant oils, with dimethyl glycine then neutralizing the mix with sodium hydroxide. The result is a white to off-white powder that dissolves in water and carries a mild, soap-like scent. Chemically it belongs to a group called betaines, which are known for their mild surface activity.
The cosmetic world first explored betaine-type compounds in the 1960s when formulators were looking for gentler ways to cleanse skin without the tight, squeaky feel older soaps caused. Over time Sodium Stearyl Dimethyl Glycine gained favor because it cleans well yet feels soft on skin and blends smoothly with oils and water.
Manufacturing starts with vegetable-derived stearic acid that is converted to stearyl dimethyl amine. This intermediate is treated with chloroacetic acid to add the carboxymethyl group, then neutralized with sodium hydroxide to yield the final sodium salt. Strict purification steps remove excess salts and byproducts, giving a high-purity powder suitable for personal care.
You will most often find Sodium Stearyl Dimethyl Glycine in facial cleansers, cream cleansers, micellar waters, makeup removers, light lotions and two-phase cleansing oils. It also appears in some hair shampoos and conditioning masks where a mild cleansing boost and creamy feel are wanted.
Sodium Stearyl Dimethyl Glycine’s Cosmetic Benefits/Uses
This multitasker supports both the cleaning power and texture of many formulas.
- Cleansing: Acts as a mild surfactant that lifts away dirt, oil and makeup while helping water rinse them off the skin. It creates a soft foam that feels gentle, making it ideal for sensitive or dry skin types.
- Emulsifying: Helps oil and water stay blended, so creams remain smooth and stable from the first use to the last. This improves spreadability and prevents products from separating in the jar or bottle.
Who Can Use Sodium Stearyl Dimethyl Glycine
Sodium Stearyl Dimethyl Glycine is generally well tolerated by all skin types, including sensitive, dry, combination and mature skin thanks to its mild surfactant action and fatty acid backbone that helps reduce the stripped feeling harsh cleansers can cause. Oily and acne-prone skin can also use it because the ingredient rinses clean without leaving a heavy residue that might trap oil. People with a known allergy to betaine-type surfactants should avoid it but that is quite rare.
The compound is usually sourced from plant-derived stearic acid so it is suitable for vegans and vegetarians. If a brand does not specify a vegetable source, those who strictly avoid animal by-products should confirm origin with the manufacturer.
No published data links Sodium Stearyl Dimethyl Glycine to reproductive toxicity so pregnant or breastfeeding individuals can generally use products containing it. This is not medical advice and anyone who is expecting or nursing should review their skincare routine with a qualified healthcare provider.
The ingredient does not make skin more sensitive to sunlight and there is no evidence of hormone disruption, so daily use does not require extra sun precautions beyond standard SPF habits. It is also mild enough for use in children’s products, although parents may want to stick to age-appropriate formulas.
Potential Side Effects/Adverse Reactions
Side effects from topical Sodium Stearyl Dimethyl Glycine differ from person to person. The points below outline potential reactions, yet most users will not experience them when the ingredient is properly formulated and used as directed.
- Mild skin irritation such as itching or stinging, more likely on already compromised or very dry skin
- Transient redness in people with extremely reactive or rosacea-prone skin
- Allergic contact dermatitis in the rare event someone is sensitised to betaine-type compounds
- Eye irritation if the raw ingredient or a foamy cleanser accidentally gets into the eyes
- Product build-up leaving a filmy feel or dull hair when used in high concentrations and not rinsed thoroughly
If any of these reactions occur stop using the product immediately and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Comedogenic rating: 1/5. Sodium Stearyl Dimethyl Glycine is derived from a fatty acid yet ends up as a highly water-soluble betaine that rinses off cleanly and does not sit in pores, so the chance of clogging is minimal. This makes it suitable for people who struggle with acne or frequent breakouts.
Only in unusually heavy leave-on formulas packed with occlusive oils might it add a hint of residue, but in most products the overall recipe, not this ingredient, determines pore-clogging risk.
Summary
Sodium Stearyl Dimethyl Glycine serves mainly as a gentle cleanser and an emulsifier, lowering surface tension to lift dirt while keeping water and oil phases smoothly blended. Its long stearyl tail adds a soft cushiony feel that leaves skin comfortable instead of tight.
It is not the most talked-about surfactant on the market yet its balanced performance has earned it a steady spot in mild face washes, micellar waters and creamy lotions where a soft clean is needed.
The ingredient is considered low risk for irritation or toxicity at normal use levels, but it is always wise to patch test any new product to make sure it agrees with your unique skin.