How to read an INCI list: the order, the 1% line, and what labels don't tell you
The front of a skincare box is advertising. The back is regulated. The ingredient list, written in a shared international vocabulary called INCI (International Nomenclature of Cosmetic Ingredients), is the single most useful thing on the packaging, once you know its few rules. They are the same rules we use in every product guide on this site, and they work for US, European and most Asian products alike.
- Ingredients are listed in descending order of amount down to those present at 1% or less, which may then appear in any order.
- In the US, color additives may be listed at the end in any order, and cosmetics that are also drugs (sunscreens, acne treatments) list their active ingredients first, in a Drug Facts box.
- "Fragrance" or "parfum" can stand for dozens of substances. In the EU, specific fragrance allergens must be named above set thresholds.
- INCI names are standardized: the same name means the same substance whatever the brand, country or language of the rest of the label.
The order rule and the 1% line
US rules (21 CFR 701.3, summarized in the FDA's Cosmetics Labeling Guide) require cosmetic ingredients to be declared in descending order of predominance. Ingredients present at 1% or less can follow in any order after those above 1%. Color additives may be listed in any order after the other ingredients. EU rules under Regulation (EC) No 1223/2009 are essentially the same.
That gives you a reading method:
- The first five or six ingredients usually make up most of the product. This is the base: water, glycerin, oils, silicones, emulsifiers. It decides texture and much of how the product feels.
- Find the 1% line. You can't see it, but some ingredients are almost always used at 1% or less: preservatives such as phenoxyethanol (limited to 1% in the EU), thickeners such as xanthan gum, chelating agents such as disodium EDTA, and fragrance. Everything after the first of these is probably at 1% or less, and their order no longer tells you the amount.
- Locate the "hero" ingredient. If an ingredient named on the front of the box appears after the preservative, it is present in a small amount, whatever the marketing says. That is not always a problem: some ingredients work at low levels, but many extracts and peptides are used as "claims" ingredients.
Drugs that look like cosmetics
In the US, a product that claims to prevent sunburn or treat acne is legally an over-the-counter drug as well as a cosmetic. Its label must carry a Drug Facts box with the active ingredients and their percentages first, then purpose, uses, warnings and directions, and then the "inactive ingredients" in the cosmetic way. Sunscreens, acne products with benzoyl peroxide or salicylic acid, antiperspirants and anti-dandruff shampoos all fall into this group. This is useful: it is one of the few places where a US label tells you a percentage.
Other countries draw the line differently. In the EU and in ASEAN countries, including Malaysia, sunscreens are cosmetics, and UV filters appear in the ordinary ingredient list. In Korea, sunscreens are "functional cosmetics" reviewed by the regulator. A Korean or European sunscreen bought in the US, or the reverse, may therefore have a very different-looking label for a very similar formula.
What the list doesn't tell you
- Exact concentrations. Apart from drug actives, there are none. A "10%" on the front is a brand claim; the list only shows rank.
- pH. It matters for acids and some vitamin C forms, and it is almost never printed.
- Fragrance components. "Fragrance" (US) or "parfum" (EU) can be a blend of many substances, and US law allows it to be declared as a single word. The FDA also allows ingredients accepted as trade secrets to be declared as "and other ingredients" at the end.
- Where an ingredient comes from, how it was made, or whether a "natural" extract is standardized.
- Whether the product works. A good list is necessary, not sufficient.
Fragrance allergens: the EU list
Because fragrance allergy is common, EU law requires certain fragrance substances to be named individually when they exceed 0.001% in leave-on products and 0.01% in rinse-off products. Regulation (EU) 2023/1545 expanded that list from 24 to around 80 named substances, with transition periods for products already on the market. Typical names include linalool, limonene, citronellol, geraniol, coumarin and hexyl cinnamal. You will see them at the end of many lists, including on US products also sold in Europe, as in the honey leave-in conditioner we decode. In the US, the 2022 Modernization of Cosmetics Regulation Act (MoCRA) directs the FDA to write a rule on fragrance allergen labelling; it had not been finalized at the time of writing.
Worked example
Take the published list of a US hyaluronic acid serum, as decoded in our Naturium guide: Aqua, Glycerin, Propanediol, Hydrolyzed Hyaluronic Acid, Sodium Hyaluronate, …, Phenoxyethanol, …
- Water, glycerin and propanediol: the base, likely the large majority of the product.
- Two hyaluronic acid forms high on the list: consistent with a hyaluronic acid serum.
- Phenoxyethanol later on: everything after it is in the small-amount zone.
A three-ingredient list, like the hypochlorous acid spray (water, sodium chloride, hypochlorous acid), is the simplest possible case: easy to check against a patch test, and easy to compare with a suspected counterfeit.
Symbols on the box
| Symbol | Meaning | Where |
|---|---|---|
| Open jar with "12M" | Period after opening: use within 12 months of opening | EU rule for products lasting more than 30 months; common worldwide |
| Hourglass with a date | "Best used before" date for products with a shorter life | EU |
| EXP date | Expiry date | US OTC drugs such as sunscreens, unless stability data support 3 years |
| Batch or lot code | Production batch, used for recalls and to check authenticity | Everywhere |
Checking an ingredient yourself
The European Commission's CosIng database lists INCI names, their functions (humectant, emollient, preservative…) and any restrictions under EU law. It is free and searchable. For ingredients that are drugs in the US, the FDA's monographs and labels are the reference. When a list contains something you have reacted to before, note the exact INCI name; it is what a dermatologist will ask for, and it is the same in any country. Our guide to patch testing explains what to do next.
Sources
- US Food and Drug Administration, Cosmetics Labeling Guide (21 CFR 701.3), FDA.
- European Commission, CosIng – Cosmetic ingredients database.
- Regulation (EC) No 1223/2009 on cosmetic products, Official Journal of the European Union, 2009.
- Commission Regulation (EU) 2023/1545 on the labelling of fragrance allergens in cosmetic products, Official Journal of the European Union, 2023.
- US Food and Drug Administration, "Modernization of Cosmetics Regulation Act of 2022 (MoCRA)", FDA, consulted October 2026.
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