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Surfactant

Sodium Lauryl Sulfate (SLS)

The most famous cleansing surfactant — and the most discussed. SLS provides a dense, stable foam and effectively cleanses, but can disrupt the skin barrier with regular use. Knowledge about it will help make the right choice.

SurfactantFoamingCleansingsulfate-free
⚠ Use with Caution
Comedogenic Rating
0/5
Irritation Potential
1/5

What is it?

SLS (Sodium Lauryl Sulfate) — an anionic surfactant, sodium salt of lauryl sulfate. Excellent foaming and cleansing, but high irritability: denatures skin proteins, disrupts the barrier lipid structure, and raises pH. It differs from SLES (Sodium Laureth Sulfate), which is milder. In INCI: Sodium Lauryl Sulfate.

Traditional surfactant in toothpaste, shampoos, and shower gels. In modern facial skincare products — replaced with milder alternatives.

Key Benefits

✦
Effective cleansing and stable foam
One of the most effective cleansers of grease, dirt, and impurities. Provides dense, stable foam even in hard water — hence its long-term use in household chemicals and cosmetics.
◈
Standard for irritation testing
SLS ironically serves as the standard for skin irritation testing in scientific research — it reacts so predictably. Barrier repair products are tested against SLS damage.
✧
Effective against heavy contamination
For cleaning tools, heavily soiled hair, or in industrial cosmetics — SLS remains an effective choice where gentleness is not a priority.

Suitable for

Oily hair (shampoo, once a week)NOT recommended for sensitive facial skin

Main Actions

✓ Effective cleansing✓ Foaming✓ Degreasing
SLS vs SLES — what’s the difference?

SLS (Sodium Lauryl Sulfate) — a stronger cleanser, more irritating. SLES (Sodium Laureth Sulfate) — milder due to ethoxylation (addition of EO groups), but may contain the impurity 1,4-dioxane. Both are 'sulfates'. 'Sulfate-free' shampoos usually use CAPB, SCI, APG, or amino acid surfactants instead.

CategorySurfactants

Frequently Asked Questions

What does Sodium Lauryl Sulfate (SLS) do for skin?
Traditional surfactant in toothpaste, shampoos, and shower gels. In modern facial skincare products — replaced with milder alternatives.
Who should use Sodium Lauryl Sulfate (SLS)?
Sodium Lauryl Sulfate (SLS) is suitable for: Oily hair (shampoo, once a week), NOT recommended for sensitive facial skin.
Are there any warnings about Sodium Lauryl Sulfate (SLS)?
SLS (Sodium Lauryl Sulfate) — a stronger cleanser, more irritating. SLES (Sodium Laureth Sulfate) — milder due to ethoxylation (addition of EO groups), but may contain the impurity 1,4-dioxane. Both are 'sulfates'. 'Sulfate-free' shampoos usually use CAPB, SCI, APG, or amino acid

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