Coco-Glucoside
In plain terms
A mild, plant-based foaming cleanser from coconut sugar, common in natural and sensitive-skin products. It is not ethoxylated, so no 1,4-dioxane. The catch is the same as its cousin decyl glucoside: it belongs to a family of surfactants that have become a notable cause of cosmetic allergy.
What the evidence shows
Coco-glucoside is an alkyl polyglucoside, made by joining glucose to coconut-derived fatty alcohols, and it is the most widely used member of that gentle, plant-based surfactant family. It foams softly, comes from renewable sources, and is not ethoxylated, so it sidesteps the 1,4-dioxane question that follows sulfates and PEGs. In the supplier's own controlled tests it was not an irritant or sensitizer, and most people use it without trouble. It lands at depends rather than no concern because of the company it keeps. Alkyl glucosides as a group, decyl, lauryl, coco, and the rest, have become recognized emerging contact allergens, and people sensitized to one frequently react to several, since they cross-react. Across patch-test clinics about 0.65 to 1 percent of tested people react to at least one alkyl glucoside, and roughly 8 in 10 of those react to more than one. Decyl and lauryl glucoside are the markers dermatologists usually test, but coco-glucoside is the one most often in the bottle, so for someone already sensitized to the family it is a likely trigger. For the majority it is a gentle, eco-friendly cleanser; for the growing group sensitized to alkyl glucosides, it is best treated like the rest of the family and avoided.
On the label
Listed as coco-glucoside, often alongside decyl or lauryl glucoside in gentle and natural cleansers. Fine for most skin. But if you have eczema or have ever reacted to a mild plant-based cleanser, get the alkyl glucosides patch-tested, since reacting to one usually means reacting to coco-glucoside too.