Cleansing and sulfates: SLS (Sodium Lauryl Sulfate)
Sodium Lauryl Sulfate (SLS) is a powerful, traditional surfactant that has long been used in shampoos and cleansing products to create a rich lather and effectively dissolve grease and dirt. However, because SLS has a very strong degreasing effect, it can strip away the skin’s and scalp’s natural protective oils, which can lead to dryness, irritation, and frizzy hair. To provide a gentler cleanse, we therefore leave SLS out of our shampoos and instead use the milder, plant-based, sulfate-free alternative Sodium Cocoyl Isethionate (SCI), which cleanses effectively without disrupting the natural moisture balance.
SLS (Sodium Lauryl Sulfate)
Benefits
- Deep cleansing
- Produces a rich lather
- Dissolves grease
Category
- Surfactants
- Cleansing ingredients
INCI name
Sodium Lauryl Sulfate
SLS at a glance
- An extremely effective and common cleansing ingredient in hygiene products
- Produces a very rich, thick, satisfying foam
- Has a small molecular size that can penetrate and irritate sensitive skin
- Often extracted from coconut or palm oil, but undergoes a chemical process (sulfation)
SLS description
SLS (Sodium Lauryl Sulfate) is one of the best-known and most effective surfactants in the cosmetics world. It is a surface-active ingredient whose primary purpose is to reduce the surface tension of water so that dirt, oil, and sebum can be effectively lifted from the skin and hair and rinsed away. The ingredient is very popular in commercial shampoos, shower gels, and toothpastes thanks to its unparalleled ability to create a rich, stable lather.
Despite its effectiveness, SLS has become controversial in skincare circles. Because its molecules are relatively small, they can penetrate deeper into the skin’s outermost layers. At high concentrations or with prolonged contact, SLS can strip away the skin’s natural oils, which can lead to dryness, irritation, and a weakened skin barrier. It is therefore an ingredient best suited to products that are quickly rinsed off, or to formulas for people who do not have sensitive or dry skin.