How to read a cosmetics label

A cosmetics ingredient list looks like a food ingredient list and is read like one, which is where the trouble starts. The rules are different in two specific ways, and both of them limit what you can conclude.

Drugs

States the active and its strength

Supplements

States amounts, above the line only

Cosmetics

States an order. No quantities at all

Order tells you something, then stops

The US rule opens the way you would expect: the label “shall bear a declaration of the name of each ingredient in descending order of predominance”. Most of a product is the first two or three things listed, usually water and an oil or a humectant.

Then comes the part almost nobody knows. The same regulation permits an alternative: ingredients above 1 percent in descending order, followed by ingredients “present at a concentration of not more than 1 percent, without respect to order of predominance”, followed by colour additives, also without respect to order.

So the list has a cliff in it. Above 1 percent, position means quantity. Below 1 percent, position means nothing at all, and the label does not mark where the cliff falls.

This matters because the interesting ingredients are usually below it. Actives, preservatives, fragrance components: all typically under 1 percent. Two products can list the same active in what looks like a meaningfully different position and contain the same amount, or list it identically and contain ten times as much.

The useful reading, then:

Near the top is real. If something is in the first few entries, there is a lot of it.

Near the bottom means not much, not less than the one above it. A serum advertising an active that appears twenty-fourth has told you the active is under 1 percent. It has not told you whether that is 0.9 percent or 0.01 percent, and there is no way to tell from the list.

A number on the front is worth more than a position on the back. Products that state a concentration are making a claim they can be held to.

One word can stand for dozens of substances

The second rule is in the same sentence as the first: each ingredient by name, “except that fragrance or flavor may be listed as fragrance or flavor”.

So “fragrance”, or “parfum”, is a lawful entry covering a mixture that may contain dozens of individual materials. For most people this is irrelevant. For anyone whose skin reacts to scented products it is the single biggest hole in the document, because the thing causing the reaction is inside a word rather than named.

Europe closes part of this. Twenty-six fragrance materials associated with contact allergy have to be named individually once they pass a concentration threshold, which is why the same product can carry a longer list in one market than another. Benzyl salicylate is one of them, and seeing it spelled out is a sign you are reading the more informative version of the label.

If your skin flares and you have not worked out why, those named fragrance allergens are the list to start from, and the wider approach is on the page for skin that reacts to everything.

What INCI names are, and why they look alarming

Cosmetic ingredients are declared under INCI names, an international naming system. It is why water is Aqua, why shea butter is Butyrospermum Parkii Butter, and why a label made entirely of things you would recognise in a kitchen reads like a chemistry paper.

The length and strangeness of an INCI name carries no information about risk. It is a naming convention, and treating it as a warning is the most common mistake in cosmetic label reading. That habit is what makes a “clean” claim feel meaningful when it is not, which is covered in the guide to what natural and clean legally mean.

The ingredients people look up most

Three preservatives and surfactants account for most of the anxiety, and in all three cases the evidence is calmer than the reputation.

Parabens are the most avoided preservatives in the category, on the strength of a study that found them present in tissue rather than showing they caused anything.

Phenoxyethanol is what replaced them in many formulations, and the review evidence describes it as one of the best tolerated preservatives in use.

Sodium lauryl sulfate genuinely irritates skin, which is a real finding and not the one the internet reports. It is not a carcinogen, and it is not an allergen either.

What the label cannot do

Tell you the concentration of anything below 1 percent. Tell you what is inside “fragrance” unless your market requires it named. Tell you whether a formulation suits your skin, which is an individual matter no list resolves.

And it cannot tell you whether a product works. An ingredient list is a declaration of contents, not of effect, and a good ingredient at an ineffective dose reads exactly like a good ingredient at an effective one.