Sodium Lauryl Sulfate: Comedogenic Rating & Safety Profile

What is Sodium Lauryl Sulfate?

Sodium lauryl sulfate (SLS) is an anionic surfactant — a powerful cleansing and foaming agent commonly used in shampoos, body washes, toothpastes and household cleaners. It is highly effective at stripping oil and producing dramatic foam, but it does so by disrupting the skin's natural lipid barrier. In dermatological research SLS is so reliably irritating that it is used as a positive control in patch testing — meaning researchers apply it deliberately to test how irritated skin responds to other ingredients.

Comedogenic Rating: What 5/5 Means for Your Skin

SLS is rated 0/5 for true comedogenicity but its effect on the skin barrier indirectly worsens acne — by stripping the barrier, it triggers compensatory oil production and inflammation that can drive breakouts. The 5/5 ratings sometimes seen for SLS reflect this practical 'clogging through irritation' effect rather than direct pore blockage.

• Cheap and produces high foam (cosmetically only)

Irritancy rating is the maximum (5/5). Common effects include dryness, redness, stinging, peeling and worsened eczema, rosacea and acne. SLS in toothpaste is a documented trigger for canker sores (recurrent aphthous ulcers). Compromised barriers, sensitive skin, eczema, rosacea and children should avoid SLS-containing products.

Avoid in any leave-on or facial product. For body washes and shampoos, look for gentler alternatives like sodium cocoyl isethionate, cocamidopropyl betaine or decyl glucoside, especially if you have sensitive or barrier-damaged skin.

SLS is in many drugstore shampoos, body washes, foaming face washes, toothpastes and household cleaners. Cleaner cosmetic brands have largely moved away from it.