CosmeticBet
Cleansers

Cocamidopropyl betaine

INCI: COCAMIDOPROPYL BETAINE · also CAPB

A gentle cleanser common in shampoos.

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C19H38N2O3342.50 g/mol
Shown with a C12 (lauric) chain: lauric acid is the main fatty acid of coconut oil
oxygennitrogencarbon
2D drawing from PubChem 20280 (hydrogens hidden)

How common

All products19%
In shower gels72%
In shampoos59%
In toothpastes19%

2,753 of 14,784 products with a full ingredient list in Open Beauty Facts; No. 11 of all the names found on their labels.

What it is

  • A synthetic cleanser (surfactant) whose molecule carries both a positive and a negative charge.

    2 sourcesHide
    Cocamidopropyl betaine (CAPB) is an amphoteric synthetic detergent[1] Review · 2008 · open source
    are zwitterions used mainly as surfactants in cosmetics[2] US Cosmetic Ingredient Review expert panel · 2012 · open source

Why it is in products

  • A mild cleanser and foam-maker, chosen because it irritates skin relatively little. In shampoos it foams well and leaves hair manageable.

    2 sourcesHide
    because it induces relatively mild skin irritation[1] Review · 2008 · open source
    foam well and leave hair in manageable state[3] Study · 2015 · open source

Downsides and safety

  • It is a known skin allergen: it was named “Allergen of the Year” for 2004, and estimates of sensitisation run from 3.0 to 7.2%.

    Well established2 sourcesHide
    contact sensitization prevalence is estimated at between 3.0 and 7.2%[1] Review · 2008 · open source
    The increasing rates of sensitization led to CAPB's being named Allergen of the Year in 2004.[1] Review · 2008 · open source

  • The culprits are usually impurities left over from making it (amidoamine and DMAPA). In tests, carefully purified CAPB no longer caused the allergy.

    Good evidence3 sourcesHide
    the presence of 3,3-dimethylamino-propylamine (DMAPA) and fatty acid amidopropyl dimethylamine (amidoamine) impurities, which are known as sensitizers[2] US Cosmetic Ingredient Review expert panel · 2012 · open source
    is likely to be the actual sensitizer in most cases rather than CAPB itself[4] Study · 1997 · open source
    when thoroughly purified, it no longer has a sensitizing action[5] Study · 2003 · open source

  • Hairdressers, who handle it all day, are 1.7 times as likely to become allergic to it.

    Good evidenceSourceHide
    Meta-analysis revealed that hairdressers have a 1.7-fold increased risk of developing a contact allergy to CAPB compared to controls who are not hairdressers.[6] Review · 2022 · open source

Where it works

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

On the surface of hair and skin, in products such as shampoos and bath gels that are rinsed off.

SourceHide
eg, shampoos, contact lens solutions, toothpaste detergents, makeup removers, bath gels[1] Review · 2008 · 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[7] US Food and Drug Administration · open source
    We searched the FDA’s list of prohibited and restricted cosmetic ingredients: no entry.open the list

  • The US expert panel: safe when the product is made so that it does not sensitise.

    SourceHide
    when formulated to be nonsensitizing (which may be based on a quantitative risk assessment), these ingredients are safe for use as cosmetic ingredients[2] US Cosmetic Ingredient Review expert panel · 2012 · open source

Sources

  1. Cocamidopropyl betaine Jacob SE et al., Dermatitis : contact, atopic, occupational, drug, 2008Review
  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. Shampoo and Conditioners: What a Dermatologist Should Know? Indian Journal of Dermatology, 2015Study
  4. Allergy to cocamidopropyl betaine may be due to amidoamine: a patch test and product use test study Fowler JF et al., Contact dermatitis, 1997Study
  5. The role of 3-dimethylaminopropylamine and amidoamine in contact allergy to cocamidopropylbetaine Foti C et al., Contact dermatitis, 2003Study
  6. Skin Toxicity of Selected Hair Cosmetic Ingredients: A Review Focusing on Hairdressers Symanzik C et al., International journal of environmental research and public health, 2022Review
  7. Prohibited & Restricted Ingredients in Cosmetics | FDA US Food and Drug Administration

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