Sodium Lauryl Sulfate (SLS)
INCI: Sodium Lauryl Sulfate
Anionic surfactant with strong cleansing properties. Effectively removes oil but aggressively disrupts the lipid barrier. The standard irritant in dermatological patch testing.
Evidence by route
Topical application
DVery weak or conflicting data.
A surfactant, not an active ingredient. CIR deemed safe in rinse-off products. In leave-on formulas at concentrations above 1%, it irritates skin. True SLS contact allergy is extremely rare – irritation is commonly mistaken for allergy.
- Cosmetic Ingredient Review. Int J Toxicol. 2005;24(Suppl 1):1-102.
Tolerability and safety
Irritation potential
HighAllergen risk
LowPregnancy
SafeFor sensitive skin
SLS is used as the reference irritant in patch testing. For sensitive skin, eczema, and rosacea, choose gentler surfactants (coco-glucoside, lauryl glucoside).
Skin types
Suitable for
Use with caution
Frequently asked questions
Is Sodium Lauryl Sulfate (SLS) safe during pregnancy?
Sodium Lauryl Sulfate (SLS) is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Sodium Lauryl Sulfate (SLS) for?
Sodium Lauryl Sulfate (SLS) suits: oily. Use with caution in: sensitive, dry, combination.
Can Sodium Lauryl Sulfate (SLS) irritate the skin?
Yes, Sodium Lauryl Sulfate (SLS) has high irritation potential. Start at low concentrations, introduce gradually, and always use SPF during the day.