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Sodium Lauryl Sulfate

Sodium Lauryl Sulfate

Strong anionic surfactant. Cleans well, but on facial skin it strips the barrier faster than gentler alternatives.

What it does

Sodium lauryl sulfate is the workhorse cleanser of mid-century soap chemistry — high foam, low cost, very effective at removing oil. It's also a well-documented skin irritant in patch testing, used in research as the standard barrier-disruption agent. SLS in body wash or shampoo passes by quickly; SLS as the primary surfactant in a face cleanser is the formulation choice that most often produces 'this cleanser leaves my skin tight.' Newer face cleansers prefer milder surfactants like sodium cocoyl isethionate or glucosides.

The evidence, graded

expert consensusDuring an active eczema flare, most actives (retinoids, AHAs, BHAs, vitamin C) can worsen barrier dysfunction and prolong the flare. Focus on barrier repair until the skin is calm; consult a derm if flares are recurrent.Eichenfield 2014 · Journal of the American Academy of Dermatology ↗
expert consensusIf skin is reactive, peeling, stinging, or burning unexpectedly, pause all actives and rebuild the barrier with simple cleanser, ceramide-rich moisturizer, and SPF for 2–4 weeks before re-introducing actives one at a time.Lodén 2003 · American Journal of Clinical Dermatology ↗
emergingThe skin's barrier is built from ceramides, cholesterol, and free fatty acids in a roughly 1:1:1 to 3:1:1 ratio. Moisturizers formulated to mimic that ratio support barrier repair more than any one lipid alone.Man 1996 · Journal of Investigative Dermatology ↗

Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.

Also known as

sls

Pairs worth knowing

Ceramides · works together ↗Panthenol (Pro-vitamin B5) · works together ↗Niacinamide (Vitamin B3) · works together ↗Glycerin · works together ↗

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