Cocamidopropyl Betaine (CAPB)
Cocamidopropyl betaine (CAPB) is a mild surfactant derived from coconut oil, used in shampoos, shower gels and washing-up liquids to boost lather and reduce irritation. It causes no problems for most people; the rare allergic reactions are mostly linked not to the substance itself but to impurities left over from manufacturing.
Risk range
1 is the lowest and 10 the highest risk. The range depends on the amount used, whether the product is rinsed off and how it is used. The Temiz İçerik app uses the same ranges.
It stays at the lower end in rinse-off products and with well-purified raw material; it moves towards the upper end in leave-on products and for people with a known contact allergy.
It is added to washing-up liquids for lather and to keep hands soft; because of dilution and brief contact, the risk is low.
What is cocamidopropyl betaine and what is it used for?
CAPB is an amphoteric surfactant made by reacting coconut oil fatty acids with dimethylaminopropylamine (DMAPA) and then treating the result with chloroacetic acid. Being amphoteric means it can carry either a positive or a negative charge depending on the pH; this property makes it gentler on the skin and eyes.
In products it is usually used not on its own but together with an anionic foaming agent such as SLES. This combination makes the lather richer, thickens the product and reduces the irritating effect of the main surfactant. It is also often found in “tear-free” baby shampoos.
Which products contain it?
- Shampoos, shower gels, facial cleansing gels and liquid soaps
- Baby shampoos and cleansers for sensitive skin
- Washing-up liquids and some surface cleaners
- Some make-up removers and wet wipes
Is it harmful? The scientific assessment
The CIR found cocamidopropyl betaine safe in cosmetics when formulated to be non-irritating. Its acute toxicity is low, and it is not classified as a carcinogen or an endocrine disruptor.
The main issue discussed is contact allergy. In the 2000s, reactions to CAPB in patch tests drew attention, and later research showed that most of these reactions were linked to two impurities left over from manufacturing, amidoamine and DMAPA. As a result, manufacturers moved towards producing purer raw material, and experts recommended keeping these impurities low.
CAPB allergy is rare in the general population. When a reaction occurs, it usually appears as itchy eczema on the eyelids, face, scalp or neck.
Who should be careful?
- People found to be allergic to CAPB, amidoamine or DMAPA in a patch test: They are advised to read labels and choose products without these substances.
- People with unexplained eczema on the eyelids or scalp: They can ask their dermatologist whether shampoo and shower gel might be a trigger.
- People with very sensitive skin: Because exposure lasts longer with leave-on products, it helps to try new products on a small area first.
What to do when you see it on a label
If you don't have a known allergy, products containing cocamidopropyl betaine are often a gentler option than sulphate products. If you do have an allergy, look out not only for this name but also for amidoamine names such as “cocamidopropyl dimethylamine”. As an alternative, glucoside-based cleansers such as coco-glucoside or decyl glucoside can be chosen; but remember that these too can rarely cause allergies.
Frequently asked questions
Is cocamidopropyl betaine natural?
It is derived from coconut oil, but it is a semi-synthetic substance made by chemical processing. It is more accurate to call it “naturally derived”.
Why is it in sulphate-free shampoos?
CAPB is not a sulphate. Because it provides mild cleansing and lather, it is one of the key ingredients in sulphate-free formulas.
How can a CAPB allergy be identified?
A definite diagnosis is made with a patch test carried out by a dermatologist. If you have recurring itching or redness after a particular shampoo, you should see a doctor.
Sources
Updated: 2026-10-11 · How we score
This page is for general information and is not personal medical advice. Warnings on the product label and the advice of a health professional always come first.