Ammonium Laureth Sulfate vs Sodium Lauryl Sulfate: which is worse?

What is Ammonium Laureth Sulfate?

Ammonium laureth sulfate is an anionic surfactant very similar in structure to SLES but uses an ammonium counterion instead of sodium. It produces abundant foam and provides excellent conditioning to the hair shaft during washing.

What is Sodium Lauryl Sulfate?

Sodium lauryl sulfate is an anionic surfactant derived from lauryl alcohol (from coconut or palm oil). It is one of the oldest and most-studied cosmetic surfactants, prized for its powerful foaming and degreasing properties. Unlike SLES, it is not ethoxylated.

Documented risks

Ammonium Laureth Sulfate: Ammonium laureth sulfate shares a similar safety profile to SLES. The CIR has concluded it is safe for cosmetic use. Like SLES, it may contain trace 1,4-dioxane from ethoxylation, addressed by standard manufacturing controls. It is not a carcinogen or endocrine disruptor. Mild skin irritation is possible in sensitive individuals at high concentrations but is not a concern at typical use levels in rinse-off products.

Sodium Lauryl Sulfate: SLS is safe at cosmetic use concentrations per the CIR Expert Panel. It is more irritating than SLES to skin and mucous membranes, particularly at concentrations above 2% with prolonged contact; this is why most rinse-off products keep it at 1–2% or opt for SLES. It can disrupt the skin barrier transiently, which is why some people with canker sores or eczema avoid SLS toothpastes and cleansers. It is not carcinogenic, not a hormone disruptor, and is not absorbed systemically in meaningful amounts. It biodegrades rapidly in the environment.