How to compare two skincare ingredient lists

How to compare the labels

1. 1Get both complete ingredient panels. On US products, check the outer carton as well as the bottle. If an online listing lacks ingredient information, ask the seller rather than filling the gaps yourself.
2. 2Check the product identity and intended use. Put the names and countries of sale beside your lists. Cosmetic requirements differ between countries, and a product with a treatment purpose can also be regulated as a drug.
3. 3Mark matching names, then list the names found only in product A or product B. Keep the label wording intact so you can ask the manufacturer about an unfamiliar name without accidentally asking about something else.
4. 4Compare positions cautiously. US cosmetic ingredients generally appear in descending order of predominance, but color additives and ingredients at 1% or less are exceptions. Do not turn a position into an invented concentration.
5. 5Check any separate active ingredient section. US products that are both cosmetics and drugs identify drug ingredients as active ingredients before the cosmetic ingredients. Compare those separately rather than mixing everything into one ranking.
6. 6Read directions and warnings beside the ingredients. A useful comparison includes how each product is meant to be used, not just what names appear on the panel.

Online descriptions can be misleading or inaccurate, so compare the label rather than the sales pitch, which is already quite committed to liking the product. For cosmetics sold in Canada, look for an English and French label with ingredients, directions, cautions and consumer contact information.3

What does ingredient order actually tell you?

An ingredient appearing earlier in one list than another is not enough to calculate which product contains more of it. Each list orders its own formula; the positions are not a shared measuring scale. The 1% exception also means that the end of a US list is not a reliable concentration ranking. Keep your notes literal: "listed earlier" is an observation; "twice as much" needs an actual quantity.2

Which differences matter if you have an allergy?

Prioritise ingredients you know or suspect you are allergic to. Avoid products containing those ingredients rather than choosing by list length. Fragrances and preservatives are common causes of cosmetic allergy, but preservatives also prevent bacterial or fungal growth in cosmetics containing water. Their presence is not, by itself, a reason to reject a formula.14

Fragrance needs a closer check. US labels can use "fragrance" or "perfume" without naming every component. "Unscented" products can contain fragrance used to mask other smells. If you need to avoid a particular fragrance ingredient and the panel leaves that unclear, contact the manufacturer.14

Can you rely on "hypoallergenic" or "for sensitive skin"?

In the US, "hypoallergenic", "fragrance free" and "for sensitive skin" have no federal standard or definition governing their use. Keep the comparison focused on named differences rather than choosing the most reassuring slogan, since both bottles have appointed themselves the better bottle.1

What if you are comparing products after a reaction?

Shared ingredients give you names to discuss with a clinician, not a diagnosis. Cosmetic allergy can develop after years of use without previous problems. Avoid the suspected product and seek medical advice for a suspected allergic reaction; a clinician can use patch testing to help identify the allergen. Trouble breathing or swallowing requires immediate medical attention.14