Sodium Surfactin

Sodium surfactin is a biosurfactant—a cleaning agent derived from fermentation of the bacterium Bacillus subtilis. It functions as both a surfactant and emulsifier in skincare formulations, meaning it helps remove oil and dirt from the skin whilst also allowing oils and water to mix smoothly together in a product.Unlike many synthetic surfactants, sodium surfactin is produced through a biological process, making it of interest to formulators seeking naturally-derived alternatives. It appears in a small proportion of skincare products, typically in cleansing or gel-based formulations.

Sodium surfactin works by having a dual-natured molecular structure: one end loves water and the other loves oil. When you apply a cleanser containing it to your skin, these molecules surround dirt and sebum, allowing them to be rinsed away with water. This mechanism is gentler than harsher surfactants because sodium surfactin typically requires lower concentrations to be effective.In formulations, it also acts as an emulsifier, meaning it stabilises the blend of oil and water-based ingredients so they don't separate, improving both texture and shelf stability.

Sodium surfactin is typically encountered in cleansers, micellar waters or gel-based formulations rather than serums or creams. Use these products as directed by the specific brand—usually as part of your daily cleanse. If using a cleanser containing this ingredient, apply to damp skin, massage gently, and rinse thoroughly with water. Follow with your usual toner, essence or moisturiser depending on your routine.

Sodium surfactin is generally well-tolerated and considered safe for topical use in skincare products. As with any active ingredient, discontinue use if irritation or sensitivity develops and consider patch testing first if you have very reactive skin.