Sodium Lauryl Sulphate (SLS) is an anionic surfactant widely used as a foaming and cleansing agent in shampoos, cleansers, and toothpastes. It effectively emulsifies oils and removes dirt but is known to be a potential skin and mucosal irritant at higher concentrations.
| Reported effect | How often | Notes |
|---|---|---|
| Skin irritation and dryness | Common | Disrupts skin barrier lipids, leading to dryness, redness, and stinging, especially with prolonged or repeated contact. |
| Transepidermal water loss / barrier disruption | Common | Used as a standard irritant in patch-test research due to its reliable disruption of the stratum corneum. |
| Contact dermatitis (irritant) | Uncommon | More likely in individuals with sensitive skin or existing dermatitis; concentration-dependent. |
| Eye irritation | Uncommon | Can cause stinging or redness on accidental ocular contact in cleansing products. |
| Oral mucosal irritation / aphthous ulcers aggravation | Uncommon | Reported with SLS-containing toothpastes in some individuals. |
| Allergic contact dermatitis (true sensitization) | Rare | SLS is primarily an irritant rather than a true allergen; genuine allergic reactions are uncommon. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.