Understanding INCI Names Across Markets

You are comparing a Korean toner with an American serum. The ingredient lists look different, but you suspect they are similar products. The bridge between them is the INCI system, and understanding how it works makes cross-market comparisons possible. Understanding how it fails is equally important, because matching names is the beginning of a comparison, not the end.

What INCI is

INCI stands for International Nomenclature of Cosmetic Ingredients. It is maintained by the Personal Care Products Council [2] and used for ingredient labeling in the EU [1], the US [3], Korea [4] and most other markets.

The system assigns a standardized name to each cosmetic ingredient. Sodium hyaluronate is sodium hyaluronate whether the product was made in Seoul, Paris or New Jersey. This makes ingredient lists directly comparable across countries, which is the single most useful thing about it. Before INCI, comparing a French moisturizer with a Korean one required a translation, a chemistry degree, or both. Now you need neither. You do still need caution, because the list answers one question, what is in this, and leaves a longer list of questions unanswered.

How INCI names work

Synthetic and purified ingredients

These use their chemical or common names: glycerin, niacinamide, retinol, dimethicone, phenoxyethanol. These are usually straightforward.

Plant-derived ingredients

These use the Latin botanical name followed by the plant part and preparation type:

INCI name	Common name
Rosa Canina Fruit Oil	Rosehip oil
Centella Asiatica Extract	Centella (cica) extract
Camellia Sinensis Leaf Extract	Green tea extract
Butyrospermum Parkii Butter	Shea butter
Simmondsia Chinensis Seed Oil	Jojoba oil

The Latin naming prevents confusion between languages. “Shea butter” is unambiguous in English, but the INCI name works regardless of the label language.

Colorants

Identified by CI (Colour Index) numbers: CI 77891 is titanium dioxide, CI 77491 is iron oxide red. These numbers are universal and do not change across markets.

Fragrance

Listed as “parfum” in the EU and “fragrance” in the US. Both mean the same thing: a mixture of scent ingredients grouped under a single term. The EU additionally requires individual listing of 26 specific fragrance allergens (expanding to 82) when they exceed threshold concentrations [1]. This means an EU label for a fragranced product is longer and more specific than a US label for the same product, not because the formula differs but because the disclosure requirements do. If you are comparing a US product listing “fragrance” with an EU product listing “parfum” followed by six allergen names, the EU label is not telling you the product is more fragranced. It is telling you what the US label is allowed to leave out.

Preservatives and functional ingredients

These use their chemical names: phenoxyethanol, ethylhexylglycerin, sodium benzoate. They are easy to identify and compare. What the INCI name does not tell you is the concentration, which matters, because a preservative at 0.1% and the same preservative at 0.9% may affect sensitive skin differently despite appearing on both lists in exactly the same way.

The 1% line

In every major market, ingredients above 1% concentration must be listed in descending order by weight. Below 1%, the manufacturer can list them in any order. This means you can roughly gauge relative concentrations of the top ingredients. If glycerin is second and niacinamide is fourth, there is probably more glycerin than niacinamide. But once you get past the first handful of ingredients, the order becomes meaningless, and two products can list the same ingredients in a different order below the 1% line without any difference in formulation.

The practical problem: the label does not tell you where the 1% line falls. A product with fifteen ingredients might have the cutoff after ingredient five or after ingredient ten, and you cannot tell from the list alone. This is why matching lists ingredient by ingredient and calling a close match works only for the top of the list. Below the 1% line, you are comparing a shuffled deck.

What INCI names do not tell you

The name identifies the ingredient. It does not tell you:

• The concentration. Two products can list niacinamide at 2% and 10% and both simply say “niacinamide.” The experiences of using those two products will be quite different.
• The molecular weight. “Sodium hyaluronate” covers a wide range of molecular weights. A high-molecular-weight version sits on the skin surface; a low-molecular-weight version penetrates deeper. Both show the same four words on the label.
• The grade or purity. “Tocopherol” (vitamin E) can be a natural or synthetic form at different purities. The biological activity of natural d-alpha-tocopherol is higher than synthetic dl-alpha-tocopherol, but the INCI name for both is simply “tocopherol.”
• The source. “Squalane” can be derived from olives, sugarcane or shark liver. The INCI name is the same regardless.
• The processing. An extract can be water-extracted, alcohol-extracted, supercritical CO2-extracted or fermented. Each method produces a different chemical profile from the same plant. The INCI name does not distinguish between them.

This is the gap where replacements fail. Two products with similar ingredient lists can perform quite differently because of what the names hide. The list answers “what,” never “how much” or “which kind.”

For more on what the ingredient list shows and leaves out, see when a dupe isn’t a dupe.

Using INCI names to compare across markets

When comparing products from different countries:

1. Find the ingredient list. On EU and Korean products, it is usually on the packaging. For products sold online from another country, check the brand’s website.
2. Match the INCI names directly. The same name means the same ingredient.
3. Note the order. Ingredients above 1% are in descending order of weight in all major markets. Below 1%, order is arbitrary.
4. Watch for regulatory differences. An ingredient permitted in one market may not be permitted in another. An EU product listing a UV filter not approved in the US tells you the formula was made for the EU market.
5. Use an INCI dictionary for unfamiliar names. The Personal Care Products Council maintains the definitive INCI dictionary [2]. Free databases also exist.

An illustrative example

This scenario is hypothetical.

A reader is comparing a Korean essence with an American serum. The Korean product lists: Water, Butylene Glycol, Glycerin, Niacinamide, Centella Asiatica Extract, 1,2-Hexanediol, Carbomer, Arginine. The American product lists: Water, Glycerin, Niacinamide, Butylene Glycol, Centella Asiatica Extract, Carbomer, Phenoxyethanol, Sodium Hydroxide.

The first four ingredients are the same set in a slightly different order, suggesting similar base compositions. Both contain centella extract and niacinamide. The preservative systems differ (1,2-hexanediol versus phenoxyethanol) and the pH adjusters differ (arginine versus sodium hydroxide), but these are functional ingredients that do not change the product’s primary purpose.

This comparison is possible because both products use INCI names. What it does not tell the reader: whether the niacinamide concentration is the same, whether the centella extract was processed the same way, and whether the product feels anything alike on the skin. The lists are the start of the investigation, not the verdict.

The ledger for this comparison:

	Matches	Does not match	Unknown
Key actives	Niacinamide, centella		Concentrations
Base ingredients	Glycerin, butylene glycol		Order may differ below 1% line
Preservative system		Different (hexanediol vs phenoxyethanol)	Skin tolerance of each
pH adjuster		Different (arginine vs sodium hydroxide)	Final product pH
Fragrance			Neither lists “parfum”, but unlisted scent from botanicals possible
Texture and feel			Only trying will tell

Common traps

• Treating a matching ingredient list as a matching product. The INCI system guarantees that the names match. It does not guarantee that the concentrations, molecular weights, grades or processing methods match. A list comparison is a filter, not a conclusion.
• Ignoring the 1% line. Two products that share twelve of fifteen ingredients may share only three of those twelve above 1%. The other nine are present in trace amounts on both lists and contribute little to the product’s behavior. You cannot tell from the list which ingredients are trace and which are functional.
• Confusing INCI name similarity with ingredient similarity. “Tocopheryl acetate” and “tocopherol” are different ingredients with different properties, despite both being forms of vitamin E. “Sodium hyaluronate” and “hydrolyzed sodium hyaluronate” differ in molecular weight and skin behavior. Read the full name, not the first word.
• Assuming the list is complete. Ingredients present below 0.001% concentration do not need to be listed under most frameworks. Trace contaminants and processing aids are not listed either. The list is a disclosure, not a recipe.

For more on comparing products from different markets, see when the replacement is from a different country. For the general replacement method, see how to replace a discontinued moisturizer.

The INCI system is the closest thing the cosmetics world has to a universal language. It is not perfect, and it leaves out more than it includes, but it is the only tool that lets you compare products across brands, borders and reformulations without relying on marketing claims.

When to see a clinician first. If you have a diagnosed contact allergy, INCI names help you identify the allergen across markets. But the INCI name does not tell you the concentration, and the same allergen at different concentrations can produce different reactions. If you are allergic to a specific ingredient, consult your dermatologist before using a product from a different market, even if the ingredient list looks safe.