Sodium Laureth Sulfate (SLES)
Ethoxylated version of SLS – gentler but still potentially irritating to sensitive skin. One of the most common surfactants in shampoos and shower gels.
Supporting ingredient
It gives a product its texture, stability or shelf life. It has no claimed effect on the skin, so an efficacy tier does not apply. What is known about its safety is below
Tolerability and safety
- Irritation potential
- Medium
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Oily, Normal, Combination
- Use with caution
- Sensitive, Dry
About this ingredient
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.
Frequently asked questions
Is Sodium Laureth Sulfate (SLES) safe during pregnancy?
Sodium Laureth Sulfate (SLES) is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Sodium Laureth Sulfate (SLES) for?
Sodium Laureth Sulfate (SLES) suits: oily, normal, combination. Use with caution in: sensitive, dry.
Can Sodium Laureth Sulfate (SLES) irritate the skin?
Sodium Laureth Sulfate (SLES) has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
What is Sodium Laureth Sulfate (SLES) and what does it do in cosmetics?
Ethoxylated version of SLS – gentler but still potentially irritating to sensitive skin.
What's the INCI name for Sodium Laureth Sulfate (SLES)?
The INCI name is Sodium Laureth Sulfate. It may also appear as: SLES.
See Sodium Laureth Sulfate (SLES) in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Similar role in the formula
Other functional ingredients
Sodium Lauroamphoacetate, Sodium Lauroyl Glutamate, Sodium Lauroyl Lactylate, Sodium Lauroyl Methyl Isethionate, Aluminum Hydroxide, Cocamide DEA, Laureth-23, Poloxamer 338
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