An ingredient list reveals the order, not the amount.

What is an INCI list?

An INCI list is the ingredient list on a cosmetic label, written with standardized names. INCI stands for International Nomenclature of Cosmetic Ingredients. In the EU, the common names used on labels come from a glossary compiled with INCI names in mind, so a substance can carry one name across products and languages. [1]

That glossary is a naming tool, not a list of approved or safe substances. A name appearing in it does not mean anyone has judged it right for your skin. [1]

The United States has its own rules. There, each ingredient is listed by name in descending order of predominance, and fragrance or flavor can be declared simply as “fragrance” or “flavor”. The two systems overlap, but they are not identical. [2] Neither one describes the rules of other countries, so treat both as examples.

Standard names matter most for people with allergies. A dermatology review built a list matching older, familiar names of known cosmetic allergens with their INCI names, so dermatologists could advise allergic patients on which names to look for. Some names may have changed since that 1997 list. [3]

The names are chosen for consistency, not readability, which is why a little label practice pays off.

What does ingredient order tell you?

Ingredient order tells you roughly which ingredients are present in larger amounts. Under EU rules, ingredients are listed in descending order of weight at the time they are added to the product. The US uses a similar descending order of predominance. Beyond that, the list does not state how much of each ingredient there is. [1, 2]

That is why water often comes first in creams and serums.

What order does not show is potency. An ingredient near the end can still matter a great deal, because some substances do their job at very low levels. Equally, an ingredient near the top is not necessarily the one doing the work you bought the product for.

In the EU, ingredients present as nanomaterials must be followed by “(nano)” in the list. Impurities in raw materials and technical aids that do not remain in the finished product are not counted as ingredients at all, so they will not appear. [1]

Why does the 1% line matter?

The 1% line is the point below which order stops being informative. In the EU, ingredients present at under 1% can be listed in any order after those above 1%. US rules allow an alternative format with the same idea: ingredients over 1% in descending order, then those at 1% or less in any order. [1, 2]

The label does not mark where that line falls. You might see a known ingredient halfway down the list and have no way to tell whether it is at 2% or 0.5%. Some brands state a percentage on the front of the pack; the ingredient list itself does not.

In practice, a useful clue can be an ingredient you know is normally used at low levels, such as a preservative. Anything listed after it is probably also present in small amounts, though this is an estimate rather than a rule.

Colorants and “may contain”

Colorants follow their own rules. In the EU, colorants other than hair dyes can be listed after the other ingredients in any order, often as CI (Colour Index) numbers such as “CI 77891”. For decorative products sold in several shades, the list may add “may contain” or ”+/-” before colorants that appear in some shades only. [1]

In the US, colorants can also be grouped at the end of the list in any order when the alternative format is used. [2]

How do you read parfum and fragrance allergens?

“Parfum” or “fragrance” on a list stands for a mixture of scent ingredients that is not broken down further. In the EU, certain fragrance substances that can cause allergies must also be named individually when present above set levels. In the original text of the regulation, that list had 26 substances. [1]

Those 26 had to be named if they exceeded 0.001% in leave-on products and 0.01% in rinse-off products. That is why you might see “linalool” or “limonene” near the end of a list, after “parfum”. [1]

The list of allergens has since been expanded. An EU regulation adopted in July 2023 (2023/1545) amended the original rules and brought additional fragrance allergens under mandatory labeling. Check current guidance if you need the full list. [4]

What do these names look like in real products? A Danish study examined the labels of 5,588 scented cosmetics recorded through a nonprofit consumer app. Among products containing at least one of the 26 allergens, 85.5% listed at least two and 73.9% at least three. Linalool (49.5%) and limonene (48.5%) were the most frequently labeled. [5]

The same study found 329 products (5.9%) that named fragrance allergens but did not list “parfum”, “fragrance” or “aroma”. That study reviewed labels only and did not measure actual concentrations. [5]

A South Korean risk assessment measured 56 fragrance allergens in 267 household and personal care products and found no meaningful risk of systemic toxicity or skin sensitization, even at the 95th percentile of exposure. Many of those products were kitchen cleaners, so the result does not describe every cosmetic, nor does it replace a patch test for someone who is already allergic. [4]

What doesn’t the label tell you?

A label does not tell you exact amounts, how ingredients interact, how the product was made, or how it will feel on your skin. Two products with similar lists can behave differently. Research on moisturizers shows that the complete formula, including so-called inactive ingredients, shapes the result. [6, 7]

A review of moisturizers found big differences between products: some formulas worsened skin while others improved its appearance and barrier function. It also noted that excipients (ingredients not counted as active) can have more pronounced effects than expected. [6]

Other gaps are practical. A list will not tell you the pH, the particle size of a mineral filter, how stable an antioxidant is in the bottle, or whether the texture suits your skin. These questions come from the full formula and packaging, not from ingredient names.

Same ingredient, different formula

In a randomized controlled trial, 78 volunteers with normal skin applied one of five preparations to one forearm for seven weeks. Simplified creams with only a few ingredients and a lipid-free gel increased water loss and the skin’s response to an irritant, while an ordinary cream with 5% urea had the opposite effect. [7]

The authors concluded that moisturizers affect the barrier of normal skin and that the effect depends on the formula’s composition. These were experimental formulas on forearm skin, so the results cannot rank shop products. The skin barrier guide explains this in more depth. [7]

The same holds for well-known actives. The niacinamide guide, retinol guide and vitamin C guide each describe why the studied formula matters as much as the ingredient name.

How do front-of-pack claims compare with the list?

Front-of-pack claims are marketing language; the ingredient list is the regulated record of what is inside. In the EU, labels and advertising may not attribute characteristics or functions to a product that it does not have. [1] Even so, comparing the two is useful: the list helps you see whether a highlighted ingredient is present, not how much.

Here are a few practical checks when a front label catches your eye:

What do the date and open-jar symbol mean?

In the EU, products that last longer than 30 months do not need a best-before date. Instead, they carry an open-jar symbol with a number of months or years, showing how long the product can be used after opening. The date rule applies to products with a shorter lifespan. [1]

So “12M” next to the open-jar symbol means about twelve months after first opening. In practice, writing the opening date on the pack with a marker makes that number usable. Changes in smell, color or texture are reasonable signs to stop using a product, whatever the symbol says.

How can you use labels in your own routine?

Use labels to spot overlaps, identify triggers and keep a record. You do not need to decode every name. In practice, it is enough to know the names of your own irritants, notice when two products share an active and keep a copy of each list.

A few practical habits cover most needs:

1. Photograph the ingredient list of each product you use, since outer boxes get thrown away.
2. Mark actives you already use so you notice duplicates across a serum, toner and moisturizer.
3. Note the opening date on anything with an open-jar symbol.
4. Record reactions next to the list, including the date you started a product.
5. Change one product at a time so the list can actually help you trace a reaction.

In the US, if a product is also an over-the-counter drug, its active ingredients are listed separately before the cosmetic ingredients. Trade-secret ingredients there may appear only as “and other ingredients” at the end. [2]

Hormonal shifts or new products can both coincide with changes in your skin. If you are tracking patterns over the month, the menstrual cycle and skin guide explains how to keep those observations in perspective.

Who should read labels more carefully?

People with a diagnosed contact allergy, a history of eczema or reactions to scented products benefit most from careful label reading. In a study of 320 eczema patients with suspected fragrance or cosmetic allergy, 10.3% reacted to at least one of the 26 labeled fragrances on patch testing. [8]

Of the 33 patients with a positive reaction, 20 (61%) had a definite clinical link between that substance and their skin problem. The study also noted that INCI naming is mandatory for this labeling in the EU, which is what makes the names searchable. These were selected patients, so the figures do not describe allergy rates in the general population. [8]

If you are pregnant or breastfeeding, reading a label will not tell you whether a product has been studied in those periods. Discuss new products and their full ingredient lists with your clinician.

Frequently asked questions

Is the first ingredient the most effective one?

No. Because the list runs by weight, the first ingredient is usually the one present in the largest amount, often water. [1] Effectiveness depends on what an ingredient does and at what level, not on its place in the list. In practice, some actives are used at low levels and sit near the end.

Can you work out amounts without percentages?

Only roughly. Order gives you a ranking above the 1% line, but below it the order can be free, and the label does not show where that line falls. A percentage printed on the front comes from the brand, not the ingredient list. For an exact figure, you would need the manufacturer’s information. [1, 2]

Can a product without “parfum” on the list contain fragrance ingredients?

It can. In the Danish label study, 329 products (5.9%) named fragrance allergens without listing parfum, fragrance or aroma. If you avoid fragrance for medical reasons, check the individual allergen names as well as the word “parfum”. [5]

Why are ingredient names in Latin and English?

In the EU, label names come from a glossary compiled with the international INCI nomenclature in mind, so one substance keeps one name across countries. [1] That is why water appears as “aqua” and plant extracts often carry botanical Latin names. Consistent names also help people with allergies: dermatologists have matched familiar allergen names to their INCI names for this purpose. [3]

References

1. Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products. Official Journal of the European Union. 2009;L342:59-209. EUR-Lex
2. 21 CFR 701.3 - Designation of ingredients. Code of Federal Regulations, Title 21, Part 701. U.S. Food and Drug Administration. eCFR
3. de Groot AC, Weijland JW. Conversion of common names of cosmetic allergens to the INCI nomenclature. Contact Dermatitis. 1997;37(4):145-150. PubMed · DOI
4. Lee H, Pack EC, Koo YJ, et al. Probabilistic risk assessment of emerging EU-regulated fragrance allergens in household and personal care products. Environ Int. 2025;200:109530. PubMed · DOI
5. Bennike NH, Oturai NB, Müller S, et al. Fragrance contact allergens in 5588 cosmetic products identified through a novel smartphone application. J Eur Acad Dermatol Venereol. 2018;32(1):79-85. PubMed · DOI
6. Lodén M. Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders. Am J Clin Dermatol. 2003;4(11):771-788. PubMed · DOI
7. Buraczewska I, Berne B, Lindberg M, Törmä H, Lodén M. Changes in skin barrier function following long-term treatment with moisturizers, a randomized controlled trial. Br J Dermatol. 2007;156(3):492-498. PubMed · DOI
8. van Oosten EJ, Schuttelaar ML, Coenraads PJ. Clinical relevance of positive patch test reactions to the 26 EU-labelled fragrances. Contact Dermatitis. 2009;61(4):217-223. PubMed · DOI