Ingredient guide

Cocamidopropyl Betaine: The 'Gentle' Cleanser That Can Still Irritate

Cocamidopropyl betaine is a mild, coconut-derived surfactant used in gentle cleansers, but it is still a recognised allergen for some. Here's the balanced picture.

What it is

Cocamidopropyl betaine (CAPB) is a surfactant derived from coconut oil. It is milder than SLS and is often used in products marketed as gentle, sulphate-free or suitable for babies, frequently alongside other surfactants to soften their effect.

The nuance

It is genuinely gentler than harsh sulphates, so it is a sensible choice for many. However, it is also a recognised contact allergen. The sensitising culprit is usually an impurity left over from manufacturing rather than the molecule itself, but the practical result is the same: some people react to products containing it.

Who tends to react

People with eczema, or those who react to “gentle” cleansers that should in theory suit them, are worth checking for CAPB. Reactions tend to affect the face, scalp and eyelids.

Where it hides

Gentle and baby cleansers, sulphate-free shampoos, body washes and facial washes. Look for Cocamidopropyl betaine, CAPB or Coco betaine.

Check products against your list

To check a product, a free browser extension like Clearya flags ingredients of concern automatically as you shop online, and SkinSAFE lets you filter a product catalogue to screen out cocamidopropyl betaine and other allergens. These rate a product on general criteria rather than against your own list.

Once you know what you are screening for, a personal-list app like ClearaScan lets you save cocamidopropyl betaine once and scan any product to flag only your triggers. It also keeps a Reaction Journal for flare-ups, a shared Care Circle so family or carers can scan for you, and a Trusted Products list for items you have cleared, and it is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)

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A note on this content. The Sensitive Skin Lab publishes general educational information, not medical advice. If you suspect you have an allergy or sensitivity, consult a qualified dermatologist or allergist. Product formulations and labels change without notice, so always check the ingredients on the product itself.