What Is Magnesium Laureth-11 Carboxylate?
Magnesium Laureth-11 Carboxylate is a magnesium salt of a fatty alcohol that has been reacted with ethylene oxide about eleven times, then finished with a carboxylate group. In simpler terms it is a soap-like molecule that carries both oil-loving and water-loving parts, which lets it mix grime with water so it can be rinsed away. The ingredient traces its roots to the mid-20th-century search for gentler surfactants to replace harsher soaps. Chemists discovered that attaching ethylene oxide chains to fatty alcohols made them milder yet still effective, and turning them into magnesium salts further reduced irritation potential. To make it, manufacturers start with lauryl alcohol sourced from coconut or palm kernel oil, add controlled amounts of ethylene oxide to build the “-11” chain length, introduce chloroacetic acid to create the carboxylate group, then neutralize the mixture with magnesium hydroxide. The resulting powder or paste is easy to blend into water-based formulas. You will most often see Magnesium Laureth-11 Carboxylate in facial cleansers, body washes, micellar waters, shampoo, bubble baths and sometimes in lightweight exfoliating masks where a mild foaming effect is desired.
Magnesium Laureth-11 Carboxylate’s Cosmetic Benefits/Uses
Its primary job in cosmetics is cleansing. The ingredient lowers the surface tension of water so oils, sweat and everyday dirt can lift off the skin or hair and rinse away easily. Because the magnesium salt form is gentle, it helps products create a soft creamy lather without stripping the skin’s natural moisture barrier, making it suitable for daily use in both facial and body cleansers.
Who Can Use Magnesium Laureth-11 Carboxylate
This surfactant is generally well tolerated by all skin types including sensitive, oily, combination and normal skin because it cleanses without stripping natural oils. Very dry or eczema-prone skin may still need a richer cleanser or follow-up moisturizer, though the ingredient itself is considered gentle.
Magnesium Laureth-11 Carboxylate is produced from plant-derived fatty alcohols and mineral magnesium so it is suitable for vegans and vegetarians. Always check the full ingredient list of the finished product to be sure no animal-sourced additives have been included.
The compound has a long record of safe use in rinse-off products and no evidence suggests it poses a risk during pregnancy or breastfeeding. That said this is not medical advice and anyone who is pregnant or nursing should have a quick word with their healthcare provider before starting any new skincare product just to be safe.
It does not induce photosensitivity, so it will not make skin more prone to sunburn. No known interactions with common active ingredients such as retinoids, vitamin C or AHAs have been reported.
Potential Side Effects/Adverse Reactions
Side effects and reactions to topical Magnesium Laureth-11 Carboxylate can vary from person to person. The following list covers potential issues but they are unlikely for most users when the ingredient is formulated correctly.
- Mild eye stinging if the cleanser gets into the eyes
- Transient skin tightness or dryness when used in very high concentrations
- Redness or irritation on extremely sensitive or compromised skin
- Rare allergic contact dermatitis presenting as itching or small rash
If any irritation or unexpected reaction occurs stop using the product and consult a dermatologist or healthcare professional.
Comedogenic Rating
Rating: 0–1 (virtually non-comedogenic)
Magnesium Laureth-11 Carboxylate is a highly water-soluble surfactant used almost exclusively in rinse-off formulas, so it spends very little time on the skin. Its molecular structure is bulky and hydrophilic which prevents it from lodging inside pores and forming plugs. For these reasons it carries an extremely low risk of clogging pores.
Suitable for acne-prone or breakout-prone skin.
Because this ingredient is usually blended with other mild surfactants, the overall comedogenicity of the finished product depends on the full formula, not just this single component.
Summary
Magnesium Laureth-11 Carboxylate is a gentle cleansing agent that loosens oil, dirt and makeup by surrounding them with its water-friendly tail so they can be rinsed away. It foams lightly, leaves the skin barrier largely intact and works well in facial cleansers, body washes and shampoos.
While not as famous as sulfates or coco glucosides it enjoys steady use among formulators looking for a mild magnesium-based alternative that still delivers a satisfying lather.
Safety data show it is low-irritation, low-comedogenic and generally safe for all skin types including sensitive skin. As with any new skincare product a quick patch test is smart practice to confirm personal compatibility.