How to read an INCI list without a chemistry degree

Every product sold in the EU lists its ingredients in a standard order. Learn the four rules that turn that block of Latin into a buying decision.

The International Nomenclature of Cosmetic Ingredients is the reason a bottle bought in Madrid and one bought in Warsaw are legible to the same reader. It is also the most underused consumer tool in the category.

Rule one: ingredients above one percent appear in descending order of concentration. Rule two: below one percent, order is arbitrary — so an active listed after the fragrance is present in trace amounts. Rule three: the twenty-six allergens the EU requires to be declared appear by name, which makes sensitised skin far easier to shop for. Rule four: plant extracts use the Latin binomial, so 'Rosa Damascena Flower Water' and 'rose water' are the same thing.

Applied together, these rules answer the question most marketing avoids: is the hero ingredient actually in there at a level that does something? If niacinamide sits fourteenth on a list of twenty, the ten percent claim on the front deserves scepticism.

None of this requires distrust. It requires reading the back of the box, which European law has already made worth reading.