INCI: Sodium Laureth Sulfate
Ethoxylated version of SLS – gentler but still potentially irritating to sensitive skin. One of the most common surfactants in shampoos and shower gels.
Topical application
DVery weak or conflicting data.
A surfactant, not an active ingredient. Less irritating than SLS. CIR deemed safe. Concerns about 1,4-dioxane contamination are addressed – modern manufacturing keeps levels below the safety threshold.
Sodium Laureth Sulfate (SLES) is the ethoxylated version of SLS, an anionic surfactant. One of the most common surfactants in shampoos, shower gels and face washes. Ethoxylation makes the molecule milder than parent SLS, but irritation of sensitive skin is still possible. Mechanism. Actively emulsifies sebum and surface soils through its anionic charge. Delivers abundant dense foam even in hard water, hence popularity in mass cosmetics. Effect on stratum-corneum proteins is roughly twice gentler than SLS but stronger than mild alternatives (SCI, cocamidopropyl betaine, glucosides). Where applied. Mass-market shampoos (L'Oreal Elseve, Garnier, Pantene), shower gels, low-tier face washes. In Spain – widespread Mercadona-tier products. Premium and pharmacy brands (CeraVe, La Roche-Posay, Bioderma) usually use SCI and glucosides. Evidence base. SLES statistically causes more irritation and xerosis in atopics than SCI or cocamidopropyl betaine (Effendy 1995, Coiffard 2008). Healthy skin tolerates it normally at up to 5%. Adding amphoteric co-surfactants (cocamidopropyl betaine) cuts irritation 2-3 fold. Safety. CIR confirmed safety as rinse-off up to 50%, in leave-on up to 1%. Concerns over 1,4-dioxane (an ethoxylation by-product) are resolved – modern purification cuts it below 1 ppm, under the EPA threshold. No carcinogenicity data. Pregnancy and lactation – safe in rinse-off formats. Zero systemic absorption. For sensitive skin in pregnancy, products with SCI or glucosides are a better pick.
Irritation potential
MediumAllergen risk
LowPregnancy
SafeSuitable for
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Sodium Laureth Sulfate (SLES) is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Sodium Laureth Sulfate (SLES) suits: oily, normal, combination. Use with caution in: sensitive, dry.
Sodium Laureth Sulfate (SLES) has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
Ethoxylated version of SLS – gentler but still potentially irritating to sensitive skin.
The INCI name is Sodium Laureth Sulfate. It may also appear as: SLES.
Published: · updated:
Use with caution