CosmeticBet
Conditioners

Stearamidopropyl dimethylamine

INCI: STEARAMIDOPROPYL DIMETHYLAMINE · also An amidoamine

A conditioner from the amidoamine family.

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C23H48N2O368.60 g/mol
oxygennitrogencarbon
2D drawing from PubChem 62109 (hydrogens hidden)

How common

All products1.2%
In conditioners27%
In hair colours16%
In shampoos0.70%

174 of 14,784 products with a full ingredient list in Open Beauty Facts; No. 221 of all the names found on their labels.

What it is

  • A fatty acid amidopropyl dimethylamine, also called an amidoamine: the same kind of substance that, as an impurity, is thought to cause most allergies to cocamidopropyl betaine.

    3 sourcesHide
    fatty acid amidopropyl dimethylamines, which function primarily as antistatic agents in cosmetic products[1] US Cosmetic Ingredient Review expert panel · 2019 · open source
    fatty acid amidopropyl dimethylamine (amidoamine)[2] US Cosmetic Ingredient Review expert panel · 2012 · open source
    is likely to be the actual sensitizer in most cases rather than CAPB itself[3] Study · 1997 · open source

Why it is in products

  • To condition hair and stop static: it is one of the positively charged agents that form a conditioner’s backbone.

    2 sourcesHide
    which function primarily as antistatic agents in cosmetic products[1] US Cosmetic Ingredient Review expert panel · 2019 · open source
    Cationic surfactants: Cetyltrimethylammonium chloride, behentrimonium or propyltrimonium, stearamidopropyl dimethylamine. They are considered the backbone of a conditioner[4] Study · 2015 · open source

Downsides and safety

  • A possible skin sensitiser, partly through an impurity (DMAPA). The US panel’s verdict: safe only when formulated not to sensitise.

    Well established2 sourcesHide
    they are potential dermal sensitizers that may be due in part by the sensitizing impurity, 3,3-dimethylaminopropylamine[1] US Cosmetic Ingredient Review expert panel · 2019 · open source
    safe as cosmetic ingredients when they are formulated to be nonsensitizing[1] US Cosmetic Ingredient Review expert panel · 2019 · open source

Where it works

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

On the hair’s surface, like the other positively charged conditioners.

Well establishedSourceHide
The negative charge of the hair is attracted to the positively charged conditioner molecules[4] 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. Safety Assessment of Fatty Acid Amidopropyl Dimethylamines as Used in Cosmetics International journal of toxicology, 2019US Cosmetic Ingredient Review expert panel
  2. Final report of the Cosmetic Ingredient Review Expert Panel on the safety assessment of cocamidopropyl betaine (CAPB) International journal of toxicology, 2012US Cosmetic Ingredient Review expert panel
  3. Allergy to cocamidopropyl betaine may be due to amidoamine: a patch test and product use test study Fowler JF et al., Contact dermatitis, 1997Study
  4. Shampoo and Conditioners: What a Dermatologist Should Know? Indian Journal of Dermatology, 2015Study
  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.