What is it?
A cleansing agent (surfactant) made by joining glucose, a simple sugar, with a blend of caprylic and decyl alcohols, which are short-chain fatty alcohols. It belongs to the alkyl glucoside family, along with decyl, lauryl and coco-glucoside. It foams and helps water lift away oil and dirt, and it is used in face washes, shampoos, body washes and other rinse-off cleansers and in some leave-on skin and hair products. Glucosides also turn up in household cleaners.
Key information
- The CIR Expert Panel concluded in 2011 that caprylyl/capryl glucoside and 18 related alkyl glucosides are safe as used when products are formulated to be non-irritating.
- It is not a sulfate and is not ethoxylated, so it is not among the ingredients the FDA links to 1,4-dioxane.
- Like other glucosides it can cause allergic skin reactions in a small share of people, and people allergic to one glucoside often react to others.
More information
Caprylyl/capryl glucoside is made by reacting glucose with a mixture of 8-carbon (caprylic) and 10-carbon (decyl) alcohols under acidic conditions. The result is a nonionic surfactant. Unlike sodium lauryl sulfate, it contains no sulfate, and its name has none of the markers (“PEG,” “-eth-” or “-oxynol-”) that the FDA links to 1,4-dioxane. In 2011 it was reported in 58 cosmetic products, split roughly evenly between leave-on and rinse-off, at 0.06 to 3 percent.
The Cosmetic Ingredient Review (CIR) Expert Panel assessed it with 18 other alkyl glucosides. The CIR found that the shorter the fatty chain, the more irritating the glucoside, and caprylyl/capryl glucoside has one of the shortest chains in the group. In two-week rabbit studies, repeated applications under a wrap caused severe irritation over time even at 3.5 percent, while uncovered applications at 3 to 9 percent caused slight irritation. Undiluted, it severely irritated rabbit eyes. Human patch tests of the longer-chain decyl, lauryl and coco-glucosides found them at most slightly irritating. The Panel concluded the glucosides are safe as used when products are formulated to be non-irritating.
The other caution is allergy. Alkyl glucosides were named the 2017 Allergen of the Year, and dermatologists report that patients commonly react to more than one glucoside. If you know you are allergic to decyl glucoside, lauryl glucoside or coco-glucoside, check labels for caprylyl/capryl glucoside as well.
Sources: Cosmetic Ingredient Review: Final safety assessment of decyl glucoside and other alkyl glucosides (2011); The Dermatologist: Update on alkyl glucosides (2017); FDA: 1,4-Dioxane in cosmetics, a manufacturing byproduct
