CosmeticBet
Cleansers

Sodium laureth sulfate

INCI: SODIUM LAURETH SULFATE · also SLES

The foaming cleanser of most shampoos.

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C16H33NaO6S376.50 g/mol
Shown with two ethoxy units
sulfursodiumoxygencarbon
2D drawing from PubChem 23682204 (hydrogens hidden)

How common

All products17%
In shower gels66%
In shampoos64%
In hair colours28%

2,521 of 14,784 products with a full ingredient list in Open Beauty Facts; No. 13 of all the names found on their labels.

What it is

  • A cleanser (surfactant) from the family of sulfated, ethoxylated alcohols.

    SourceHide
    Sodium laureth sulfate is a member of a group of salts of sulfated ethoxylated alcohols[1] US Cosmetic Ingredient Review expert panel · 2010 · open source

Why it is in products

  • It cleans and foams well, removing oil (sebum) from the scalp and hair.

    2 sourcesHide
    Laureth sulfates: These are another class of excellent detergents with good cleansing ability and foaming property which are useful for normal-to-dry hair.[2] Study · 2015 · open source
    they are very good at removing sebum from the scalp and hair[2] Study · 2015 · open source

What it does

  • Gentler than its relative sodium lauryl sulfate (SLS): in a patch-test study SLS caused a pronounced reaction and SLES a far milder one.

    Good evidenceskinSourceHide
    We found a pronounced reaction to SLS, and a far milder one to SLES.[3] Study · 2003 · open source

Downsides and safety

  • It can irritate skin and eyes, though it is not an allergen. The US panel says products must be formulated so they are not irritating.

    Well established2 sourcesHide
    Sodium laureth sulfate was demonstrated to be a dermal and ocular irritant but not a sensitizer.[1] US Cosmetic Ingredient Review expert panel · 2010 · open source
    These ingredients should be used only when they can be formulated to be nonirritating.[1] US Cosmetic Ingredient Review expert panel · 2010 · open source

  • Like other strong cleansers of its kind, it can over-clean: hair left harsh, rough, dull, frizzy and tangled.

    Some evidencehairSourceHide
    However, the excessively cleaned hair is harsh, rough, dull with frizz and prone to tangling.[2] Study · 2015 · open source

  • It can carry traces of 1,4-dioxane, a possible carcinogen that forms when ingredients with “-eth-” in their names are made. EU scientists consider traces of up to 10 ppm safe, and the FDA reports that levels have fallen over time.

    Well established6 sourcesHide
    1,4-dioxane forms as a byproduct during the manufacturing process of certain cosmetic ingredients.[4] US Food and Drug Administration · open source
    identifiable by the prefix, word, or syllables[4] US Food and Drug Administration · open source
    "-eth-,"[4] US Food and Drug Administration · open source
    1,4-dioxane is a potential human carcinogen.[4] US Food and Drug Administration · open source
    SCCS concluded that 1,4-dioxane amounts in cosmetic products are considered safe for consumers at trace levels of ≤10 ppm[4] US Food and Drug Administration · open source
    changes made in the manufacturing process have resulted in a significant decline over time in the levels of this contaminant in these products[4] US Food and Drug Administration · open source

Where it works

Surface (cuticle)Inside (cortex)Core (medulla)

On the surface of hair and scalp, where it removes oil (sebum).

SourceHide
they are very good at removing sebum from the scalp and hair[2] Study · 2015 · open source

Rules

European Union

  • No EU limit: it is not on the regulation’s lists of banned or restricted substances, preservatives or UV filters.

    How we checkedHide
    We searched Annexes II to VI of the EU regulation (consolidated text of 18 May 2026): no entry.open the list

United States

  • Not on the FDA’s list of prohibited or restricted cosmetic ingredients. In the US, cosmetics and their ingredients (other than colour additives) don’t need FDA approval before sale.

    SourceHide
    Under U.S. law, cosmetic products and ingredients, other than color additives, do not need FDA approval before they go on the market[5] US Food and Drug Administration · open source
    We searched the FDA’s list of prohibited and restricted cosmetic ingredients: no entry.open the list

Sources

  1. Final report of the amended safety assessment of sodium laureth sulfate and related salts of sulfated ethoxylated alcohols International journal of toxicology, 2010US Cosmetic Ingredient Review expert panel
  2. Shampoo and Conditioners: What a Dermatologist Should Know? Indian Journal of Dermatology, 2015Study
  3. Profile of irritant patch testing with detergents: sodium lauryl sulfate, sodium laureth sulfate and alkyl polyglucoside Löffler H et al., Contact dermatitis, 2003Study
  4. 1,4-Dioxane in Cosmetics: A Manufacturing Byproduct | FDA US Food and Drug Administration
  5. Prohibited & Restricted Ingredients in Cosmetics | FDA US Food and Drug Administration

Checked against these sources on 4 November 2026. Spot a mistake? Tell us.