Sodium Lauryl Sulfate (SLS)
Anionic surfactant with strong cleansing properties. Effectively removes oil but aggressively disrupts the lipid barrier. The standard irritant in dermatological patch testing.
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
- High
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Oily
- Use with caution
- Sensitive, Dry, Combination
For 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).
About this ingredient
Sodium Lauryl Sulfate (SLS) is an anionic surfactant with a short, harsh cleansing chain (C12). INCI: Sodium Lauryl Sulfate. Produced by esterifying lauryl alcohol with sulfuric acid and neutralizing with sodium. Main function is strong cleansing and foam. Used in toothpastes, shampoos, body washes, and cleansing masks. Typical use concentration is 0.5% (toothpaste) to 10% (concentrated shampoos). Pregnancy safety. SLS is considered safe during pregnancy. Systemic absorption through intact skin is minimal, exposure is brief in rinse-off products. Use in toothpaste and shampoo during pregnancy is unrestricted. Skin safety. A harsh surfactant with high irritation potential. SLS strips lipids from the skin, disrupts the keratin barrier with prolonged contact, and can cause dryness and flaking. SLS is used as a standard irritant in patch testing – mildness of other surfactants is benchmarked against it. Important nuance. Irritation scales with concentration and contact time. In rinse-off products (body washes, shampoos) at 1–3% SLS, irritation is uncommon in people with a healthy barrier. People with atopic dermatitis, eczema, or a damaged barrier should avoid SLS. In toothpaste. SLS in toothpaste is associated with more frequent aphthous stomatitis in predisposed individuals. People with recurrent aphthae do better on SLS-free pastes. Compared with SLES and cocamidopropyl betaine. Sodium Laureth Sulfate (SLES) is an ethoxylated form of SLS and noticeably milder. Cocamidopropyl betaine is a mild amphoteric surfactant, often combined with SLS to reduce total irritation. Non-comedogenic. SLS does not clog pores but can indirectly worsen acne through irritation and barrier disruption. Bottom line. SLS is effective but harsh. Safe during pregnancy and lactation, but people with sensitive skin, atopy, or recurrent aphthae should choose milder alternatives.
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.
What is Sodium Lauryl Sulfate (SLS) and what does it do in cosmetics?
Anionic surfactant with strong cleansing properties.
What's the INCI name for Sodium Lauryl Sulfate (SLS)?
The INCI name is Sodium Lauryl Sulfate. It may also appear as: SLS.
See Sodium Lauryl Sulfate (SLS) 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 Levulinate, Sodium Metabisulfite, Sodium Metaphosphate, Sodium Methyl Cocoyl Taurate, Aminopropyl Triethoxysilane, Coco-Glucoside, Lauryl Glucoside, Polyester-8
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