Shampoo Ingredients

Water

Water was at the top of our ingredients list on all but one of the shampoos we surveyed. Some shampoos claimed to contain purified water. Dr Allan Blackman says purified water is used in a laboratory, but it's doubtful that it would have any benefit in shampoo. Also, most people wash their hair in tap water which contains additives like chlorine and fluoride.

Surfactants

Surfectants are detergents that clean your hair and scalp. Common surfactants include:

* ammonium lauryl sulfate, ammonium laureth sulfate
* cocamidopropyl betaine
* cocoamphodiacetate
* sodium cocoglyceryl ether sulfonate
* sodium laureth sulfate
* sodium lauryl sulfate
* sodium lauryl sarosinate

Lather builders

While surfactants in shampoo clean your hair, they don't have any foaming ability. That's the job of lather builders. These don't clean your hair but give an indication of how clean it is. Oil and styling products makes it harder to lather your hair, so if there are lots of bubbles it can be a sign your hair is getting cleaner.

Common shampoo lather builders include:

* cocamide MEA
* cocamidopropyl hydroxysultaine
* lauramide MEA
* lauric DEA
* lauramine oxide
* polysorbate 20

Thickening agents

The most common and relatively cheap thickening agent used in shampoos is sodium chloride (salt or sea salt) - we found it in 30 percent of the shampoos we surveyed.

Preservatives

Liquid shampoo in a warm, wet environment is a breeding ground for bacteria, so preservatives are very important. Shampoos usually contain four or five preservatives, usually because they are sold together as a preparatory mix.

Common Shampoo preservatives include:

* DMDM-hydantoin
* methyl paraben
* phenoxyethanol
* propyl paraben

Humectants and conditioning agents

Humectants help hold water in your hair. Conditioning agents work with humectants to help keep the hair softer, shinier and give it a silky feeling.

Common humectants include:

* glycerine
* hyaluronic acid
* propylene glycol
* sodium PCA
* sorbitol

Common shampoo conditioning agents include:

* amino acids
* collagen
* panthenol
* protein
* silicone