Magnesium Oleth Sulfate

Magnesium oleth sulfate is an anionic surfactant/cleansing agent typically used in rinse-off cleansers where it can still disrupt the stratum corneum lipids and increase transepidermal water loss, a known pathway to stinging and eczema flares. Clinical experience and surfactant patch-testing literature consistently show sulfate-type anionics carry a moderate irritation risk, especially in compromised or atopic skin, even when formulated with milder co-surfactants. Given sensitive-skin populations and cumulative exposure from daily cleansing, a moderate score is warranted for patient safety. Safety Notes: Magnesium oleth sulfate is used primarily as a mild anionic surfactant in rinse-off cleansing systems; at the low end (~0.1–1%) it appears as a secondary/auxiliary surfactant or foam modifier in gentle facial cleansers and body washes. Mainstream rinse-off products commonly use it in the mid single-digits to low teens as part of the total surfactant blend, while high-foaming consumer-available shampoos/cleansers and sulfate-based cleansing concentrates can reach ~20–25% active as the primary surfactant component. It is rarely used in true leave-on skincare due to irritation/foam potential, so the practical market range is driven almost entirely by rinse-off formulations.