Disodium Laureth Sulfosuccinate vs Sodium Lauryl Sulfate: which is worse?

What is Disodium Laureth Sulfosuccinate?

Disodium laureth sulfosuccinate is a mild anionic surfactant derived from the succinic acid ester of laureth alcohol. It is considered one of the gentlest ionic surfactants available and is specifically recommended for baby and sensitive-skin formulations.

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

Disodium Laureth Sulfosuccinate: Disodium laureth sulfosuccinate is among the least irritating surfactants evaluated by the CIR. It does not penetrate the skin barrier significantly and is safe at concentrations used in cosmetics. No carcinogenic, mutagenic, or endocrine-disrupting effects have been found. It may contain trace ethylene oxide/1,4-dioxane from ethoxylation, addressed by manufacturing controls.

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.