Sodium cocoyl glutamate

What it is

Sodium cocoyl glutamate is formed from coconut fatty acids and glutamic acid. It is a mild anionic with gentle foam, used in sulfate-free shampoos and facial cleansers.

How it works

It forms anionic micelles with low skin interaction. Mixed with SLS, it reduced SLS irritation in volunteers, although that study used the related sodium lauroyl glutamate (Lee 1994).

What the studies show

• In 105 patients patch-tested with eight cleansing surfactants, none caused irritation or allergic reactions at the tested dilution. The best tolerated were sodium cocoyl glutamate, sodium lauroyl oat amino acids and disodium cocoamphodiacetate, while cocamidopropyl betaine from the standard series gave 5 positives (Corazza 2010).
• In 15 volunteers with randomized skin sites, a glutamate surfactant was much less irritating than SLS, and mixing it with SLS reduced SLS irritation (Lee 1994).
• A review gives an overview of shampoo surfactant raw materials and the trend toward sulfate-free systems (Cornwell 2018).

Skin tolerance data from human patch tests are good, while hair and scalp performance data are absent.

Side effects and safety

Irritation and allergy rates were low in the 105-patient study, and we found few allergy reports.

Bottom line

One of the better evidence-backed mild cleansers for sensitive scalps and for dry, curly hair. Expect lighter lather and gentler cleansing than a sulfate shampoo. No head-to-head scalp or hair-feel trials were found.