How to Read INCI Labels: A Beginner's Guide to Skincare Ingredients

Turn over any skincare product and you'll find a list of ingredient names that look like a chemistry exam you didn't study for. Aqua. Glycerin. Cyclopentasiloxane. Phenoxyethanol. What do these mean, and why does the ingredient list look the same on a product sold in Tokyo, Berlin, and New York? The answer lies in a standardized naming system developed over five decades: INCI, the International Nomenclature of Cosmetic Ingredients.

What Is INCI?

INCI stands for International Nomenclature of Cosmetic Ingredients. It is a system of standardized names for cosmetic ingredients, designed to ensure that the same ingredient is identified by the same name on product labels regardless of language, country, or manufacturer. When you see "Aqua" on a French moisturizer and on a Japanese serum, you're seeing INCI in action.

The INCI system assigns each ingredient a single, internationally recognized name based on a set of naming conventions:

• Water is listed as Aqua (Latin-derived, language-neutral)
• Plant-derived ingredients follow the format: Genus species (part), e.g., Camellia Sinensis Leaf Extract
• Chemical actives typically use their established chemical or trivial names in English
• Fragrance blends are collectively listed as Parfum (EU/international) or Fragrance (US)

History: The CTFA and the Development of INCI

INCI was developed in the early 1970s by the Cosmetic, Toiletry and Fragrance Association (CTFA), now known as the Personal Care Products Council (PCPC), headquartered in the United States. The first edition of the CTFA International Cosmetic Ingredient Dictionary was published in 1973, establishing standardized names for approximately 2,500 ingredients.

The driving motivation was practical and regulatory: as cosmetics trade became global in the 1960s and 1970s, the same ingredient might be called by its chemical name in one country, a trademarked name in another, and a common name in a third. A unified nomenclature benefited both consumers (who could track ingredients they were concerned about) and regulators (who needed consistent labeling for enforcement).

The dictionary is now in its 16th edition, covering over 16,000 ingredients. The PCPC maintains the INCI nomenclature in collaboration with international stakeholders; the European Commission references it through the CosIng database for EU labeling requirements.

The Ingredient Order Rule: Descending Concentration

The most important rule for reading an ingredient list is the descending order of concentration rule. Under labeling requirements in the US (21 CFR § 701.3), EU (Regulation 1223/2009 Article 19), Canada, Australia, and most regulated markets:

Ingredients must be listed in descending order of weight/concentration down to and including 1%. Ingredients present at concentrations of 1% or less may be listed in any order, after all the above-1% ingredients.

In practice, this means:

• The first ingredient is the highest by weight — in most leave-on skincare, this is water (Aqua), appearing first because water is typically 50–80% of a formula.
• The first five or so ingredients usually account for the majority of the formula's mass — emollients, humectants, emulsifiers, film formers, thickeners.
• After the above-1% ingredients, there is a transition point where active ingredients, preservatives, fragrances, and specialty ingredients appear — in any order chosen by the manufacturer.
• Identifying the 1% boundary is difficult without inside knowledge of the formula. Preservatives (like phenoxyethanol, parabens, ethylhexylglycerin) are almost always used below 1%, so they typically appear near the end of the list. Seeing a preservative can help you identify approximately where the below-1% zone begins.

What This Means for Active Ingredients

Many highly effective actives are used at concentrations well below 1%:

Active Ingredient	Typical Effective Concentration	Expected List Position
Retinol	0.025% – 1%	Often near the end; rarely above 1%
Niacinamide	2% – 10%	Middle to upper-middle of list
Hyaluronic Acid / Sodium Hyaluronate	0.1% – 2%	Variable; often in below-1% zone
L-Ascorbic Acid	5% – 20%	Middle of list in dedicated vitamin C serums
Salicylic Acid	0.5% – 2%	Often near end of list; regulated max 2% (US OTC)
Peptides	0.01% – 0.1%	Near the end, regardless of claimed importance
Preservatives (e.g., Phenoxyethanol)	0.3% – 1%	Near the end; a reliable marker of the below-1% zone

INCI vs. Common Names: A Translation Guide

One of the most practical skills in reading ingredient lists is knowing which INCI names correspond to the common names used in product marketing. Brands frequently use common names in their marketing copy while the legal ingredient list requires INCI names.

Common/Marketing Name	INCI Name	Notes
Water	Aqua	Always listed as Aqua in INCI
Vitamin C	Ascorbic Acid	L-Ascorbic Acid; derivatives have different INCI names
Vitamin E	Tocopherol	Or Tocopheryl Acetate (ester form)
Hyaluronic Acid	Sodium Hyaluronate	The sodium salt form is most common on ingredient lists; higher MW = stays at surface
Retinol	Retinol	INCI same as common name; derivatives: Retinyl Palmitate, Retinyl Acetate
Glycolic Acid	Glycolic Acid	Alpha-hydroxy acid (AHA); INCI same as common name
Lactic Acid	Lactic Acid	AHA; INCI same as common name
Salicylic Acid	Salicylic Acid	BHA; INCI same as common name; see our database entry
Niacinamide (Vitamin B3)	Niacinamide	Also listed as Nicotinamide in older labeling
Zinc Oxide	Zinc Oxide	UV filter / skin protectant; see our database entry
Titanium Dioxide	Titanium Dioxide	UV filter / pigment; see our database entry
Fragrance / Perfume	Parfum (EU) / Fragrance (US)	Collective term; EU requires 26 specific allergens listed individually
Glycerin / Glycerol	Glycerin	Common humectant; INCI uses Glycerin not Glycerol
Squalane	Squalane	Saturated form of squalene; stable emollient

Regulatory Labeling Requirements by Country

European Union

The EU has the most stringent INCI labeling requirements globally. Under Regulation (EC) No 1223/2009, Article 19, all cosmetic products sold in the EU must display ingredients in descending order of weight using INCI nomenclature. The labeling must appear on the packaging and, where applicable, on the container. There is a specific provision for products in small packaging (font size minimum 0.75 mm). Fragrance allergens at concentrations above 0.001% (leave-on) or 0.01% (rinse-off) must be individually listed — a requirement that goes beyond the US "Fragrance" collective listing.

United States

The FDA requires ingredient declaration under 21 CFR § 701.3 for cosmetics sold in the US. Ingredients must be listed in descending order of predominance — generally using INCI names, though the regulation predates the full INCI system and technically allows any "established cosmetic name." In practice, US labeling is effectively INCI-aligned. Color additives are listed separately with their US-specific color names (FD&C Red No. 40, D&C Orange No. 5, etc.) rather than INCI names for colors — a distinct divergence from EU labeling.

Japan

Japan uses a hybrid system under the MHLW's labeling standards (Notification No. 331, 2000, as amended). Cosmetics sold in Japan must list all ingredients, but Japan uses its own approved ingredient names rather than full INCI, particularly for quasi-drug (医薬部外品) functional ingredients. Many Japanese cosmetics sold internationally carry both the Japanese-market label and an INCI-labeled sticker for the export market. When reading the Japanese ingredient list, you may encounter kanji or katakana ingredient names that correspond to, but are not identical to, INCI names.

Other Key Markets

• Canada: Requires bilingual labeling (English/French); INCI names used for ingredients, mirroring US requirements.
• Australia: The TGA and NICNAS (now AICIS) framework requires INCI labeling consistent with EU/US practice for cosmetics.
• South Korea: MFDS requires full ingredient listing in descending order; uses INCI names aligned with international standards for imported products.

Reading Plant Extracts and Complex Ingredients

Plant-derived ingredients follow a structured INCI naming format: Genus species (plant part) form. Examples:

• Camellia Sinensis Leaf Extract — green tea leaf extract
• Rosa Canina Fruit Oil — rosehip oil
• Centella Asiatica Extract — cica extract (used for its triterpenoid content)
• Aloe Barbadensis Leaf Juice — aloe vera gel/juice

Fermented ingredients increasingly appear in ingredient lists, especially in K-beauty formulations. These follow the format: Organism/Substrate Ferment or Organism/Substrate Ferment Filtrate. The fermentation process changes the ingredient's properties relative to the raw material, but the INCI name tells you both what was fermented and by what organism.

Fragrance: The Most Common Hidden Complexity

Both "Parfum" (EU INCI) and "Fragrance" (US labeling) are collective declarations that can represent dozens to hundreds of individual chemical compounds. This is the most significant limitation of INCI labeling for consumers sensitive to specific fragrance molecules.

The EU goes further than the US in fragrance disclosure by requiring individual listing of 26 fragrance allergens specified in Regulation 1223/2009 Annex III when they exceed concentration thresholds (0.001% in leave-on products; 0.01% in rinse-off products). Common allergens that must be individually listed under EU rules include: limonene, linalool, citronellol, geraniol, cinnamal, eugenol, and others. If you see a long list of apparently chemical names near the end of an ingredient list on an EU-labeling product, these are often individual fragrance allergen disclosures, not additional functional ingredients.

Practical Tips for Using Ingredient Lists

• Focus on the first 5–7 ingredients for understanding the product's base character: is it water-based, oil-based, alcohol-based? What are the primary emollients and humectants?
• Look for your target actives and note their approximate position: above or below the preservative (below-1% zone) tells you roughly about concentration.
• Check for potential concerns near the top: if a high-comedogenic ingredient (isopropyl myristate, coconut oil) appears in the first five, it is likely present at a meaningful concentration.
• Use databases to look up unfamiliar names: our Ingredient Analyzer lets you paste an entire INCI list and look up each ingredient's regulatory status, function, and other properties across our 1,898-ingredient database.
• Don't judge complexity by number of ingredients: a 30-ingredient list is not inherently "worse" than a 7-ingredient list. Longer lists often include water-processing aids, stability-enhancing chelators, and multiple forms of known safe ingredients like glycerin and tocopherol.

For full ingredient data including EU, US, JP, and KR regulatory status, browse our ingredient database or use the Ingredient Analyzer to process a complete product label at once.