Sodium Laureth Sulfate

Surfactant that cleanses and creates foam, can be drying for some Sodium Laureth Sulfate (SLES) is an anionic surfactant that functions primarily by reducing the surface tension of water, allowing it to mix with and encapsulate oily dirt and debris, facilitating their removal from skin and hair. It achieves this through its amphiphilic structure, forming micelles that solubilize non-polar substances. At higher concentrations or with prolonged contact, SLES can interact with the stratum corneum by denaturing epidermal proteins and solubilizing intercellular lipids, leading to disruption of the skin barrier, increased transepidermal water loss (TEWL), and potential irritation.

The CIR Expert Panel has deemed Sodium Laureth Sulfate safe for use in cosmetics, particularly in rinse-off products. It is recognized as a potential skin irritant, especially at higher concentrations or with prolonged exposure, but is generally not considered a sensitizer. Its irritation potential is often mitigated by co-formulation with other surfactants like cocoamidopropyl betaine.

Look for products with 5-25% (most formulas use 10-20% as a primary surfactant, often combined with milder co-surfactants to mitigate irritation). for clinical efficacy.