How to compare skincare ingredient lists

Before you start: make the names match

Two lists can name one ingredient differently: Aqua or Water, a CI number or a US colour name, a Latin plant name with or without the English name in brackets.¹ Put both lists into the same form first, or the comparison will show differences that are not there. The side-by-side comparison does this for you, matching each name to the official EU name before it compares.

Use the list on the packs you actually have. Formulas change, and a list copied from an old product page may not match the bottle.

Step 1: line up the first five

Names run from most to least by weight, at least down to the 1% line, so the first few are the largest ingredients in each product.²³ Compare them first. If both start with water and glycerin and then part ways, one into a light oil and the other into a butter, they are built on different bases, however alike the claims on the front.

Step 2: find the actives and where they sit

Find the ingredient each product is sold on, such as Niacinamide in a moisturiser, and note its position. Near the top, it is likely above 1%. Further down, it could be at any level up to about 1%, because below that line names may appear in any order.²

In EU products, a preservative with a 1% legal maximum is a useful marker. Phenoxyethanol is capped at 1.0%⁴, and anything above 1% must be listed before anything below it², so a name that comes after phenoxyethanol is present at about 1% or less.

Position still cannot rank two products precisely. Fourth on one list and ninth on another could mean 3% against 0.5%, or 1.2% against 1%. The same name can also cover different grades of a material.⁵

Step 3: compare preservatives and scent

In the EU, only preservatives on the approved list in Annex V may be used, each within its own limits.² Note which ones each product uses: if you have reacted to one before, that is the name to compare.

For scent, look for Parfum, Fragrance or Aroma, then for fragrance substances named one by one after it, such as Linalool or Limonene.⁶ A list without Parfum can still carry scent from a plant oil. Lemon peel oil, for example, is itself on the EU list of fragrance allergens that must be named.⁶ Fragrance free vs unscented explains what to look for.

Step 4: check the groups you watch

If you avoid a type of ingredient, such as fragrance, silicones or drying alcohol, compare the lists for it as a group rather than name by name. A group is a fact about an ingredient, not a warning: it helps you find what you prefer to avoid. The comparison marks what both products share, what only one contains, where each ingredient sits, and what an official source flags.

A worked example

Both share a base of water and glycerin and the same main preservative, but A is built on a light oil and B on shea butter. A's niacinamide sits fourth; B's comes after phenoxyethanol, so in B it is at about 1% or less. That suggests, without proving, that A contains more. And although B has no Parfum, it still lists scent ingredients: Citrus Limon Peel Oil, which is lemon peel oil, and Limonene.

What a comparison cannot tell you

• Which is stronger. Without amounts, two lists with the same names in the same order can still be different formulas.
• Which suits you. That depends on your skin and how you use the product. A comparison shows differences, not a winner.
• Whether the materials match. One name can cover several grades of a material.⁵

Paste both lists into the side-by-side comparison, or check one at a time in the ingredient checker. For how position works, see cosmetic ingredient list order.