What an Ingredient List Actually Tells You About Concentration

Sooner or later every skincare argument arrives at the same sentence: the cheap one and the expensive one have basically the same ingredients. Sometimes they do. Almost nobody who says it has done the one check that would settle it, though, and the check is free, takes about a minute and is printed on the back of both boxes.

An ingredient list is a regulated document, not a marketing panel, and most of its order is fixed by law rather than chosen by the brand. That order carries real information about how much of each thing is in the bottle. It also carries far less than the internet believes, and the gap between those two facts is where most bad skincare advice lives. This piece is the method the rest of this site runs on, so we want to be exact about both halves.

The part of the rule that is true

Start with the United States. The relevant text is 21 CFR 701.3, and its first sentence is the whole of what most people know:

“The label on each package of a cosmetic shall bear a declaration of the name of each ingredient in descending order of predominance, except that fragrance or flavor may be listed as fragrance or flavor.”

The European rule says the same thing in different words. Regulation (EC) No 1223/2009, Article 19(1)(g): “The list of ingredients shall be established in descending order of weight of the ingredients at the time they are added to the cosmetic product.” Great Britain kept the identical wording after Brexit; we checked Article 19 on legislation.gov.uk against the EU text clause by clause and it matches character for character. The annex figures later in this piece are quoted from the EU text; the GB copy of those annexes is amended separately and no longer matches it word for word.

Two details in the European sentence have no counterpart in the American one. The order is by weight, not by volume and not by how much anyone thinks matters. And it is weight at the time they are added, not in the finished product, which is a different number for anything that evaporates or reacts during manufacture.

So the first inference is sound in both places, and it is the one to use: an ingredient printed below another is present in a smaller amount, so long as the one above it makes up more than 1% of the product. Not a smaller amount than you would like. A smaller amount, as a matter of law. Down among the ingredients that are under 1% that guarantee runs out, which is what the next section is about. Above the line it holds in both systems, and it is the basis of every ingredient comparison worth reading.

The 1% line is real in Europe and optional in America

Here is where the received wisdom goes wrong, and it goes wrong in a way that changes what you are allowed to conclude.

The version you will read everywhere is that ingredients above 1% must be in descending order, and below 1% they can be in any order. In Europe that is close to right. Article 19(1)(g) continues: “Ingredients in concentrations of less than 1 % may be listed in any order after those in concentrations of more than 1 %.” That permission is narrower than it sounds. It does not say the list stops being ordered once you drop below 1%. It says the under-1% ingredients may be shuffled among themselves, and only after the over-1% ingredients, which still have to run in strict descending order.

In the United States it is not a rule at all. The 1% grouping appears in paragraph (f) of the same section, and it opens like this:

“As an alternative to listing all ingredients in descending order of predominance, ingredients may be grouped and the groups listed in the following manner and order: (1) Ingredients, other than color additives, present at a concentration greater than 1 percent, in descending order of predominance; followed by (2) Ingredients, other than color additives, present at a concentration of not more than 1 percent, without respect to order of predominance; followed by (3) Color additives, without respect to order of predominance.”

Every operative verb there is may. The grouping is an alternative a company can take or leave. The default, in paragraph (a), is that the whole list runs in descending order from top to bottom, everything under 1% included. A US brand may use either scheme, and nothing on the label tells you which one it chose.

Now be careful about what that does and does not change, because the obvious conclusion is the wrong one. Work through the two cases. A US list built under the default is ordered from top to bottom, and a list ordered from top to bottom already satisfies the European structure. A US list built under the alternative is the European structure. So whichever scheme an American company chose, reading the label the European way is safe. The popular rule turns out to be a sound way to read a bottle and a poor description of American law at the same time, which is an odd thing for a rule to be. What you cannot do is run it the other way. An American list may well be telling you more than the European rule would guarantee, since the default orders the whole thing, and nothing on the label lets you collect on that.

A worked example with one number in it

Almost every ingredient list gives you order and nothing else. The useful exception is a product that states a concentration somewhere else, on the front of the pack or in its name, because one stated number turns the whole list into a measuring stick.

Take Paula’s Choice SKIN PERFECTING 2% BHA Liquid Exfoliant. The brand publishes the full list on its own product page, and it runs to eight items:

• Water
• Methylpropanediol
• Butylene Glycol
• Salicylic Acid
• Polysorbate 20
• Camellia Oleifera
• Sodium Hydroxide
• Tetrasodium EDTA

The BHA in the product name is salicylic acid, and the name puts it at 2%. Salicylic acid is fourth of eight. That one fact, run through the descending-order rule, bounds every other ingredient in the bottle.

• Positions 1 to 3, Water, Methylpropanediol, Butylene Glycol. Each present at 2% or more, in descending order. Water is almost always first and almost always the bulk of the product.
• Position 4, Salicylic Acid. Stated by the brand at 2%. This is the anchor.
• Positions 5 to 8, Polysorbate 20, Camellia Oleifera, Sodium Hydroxide, Tetrasodium EDTA. Each present at 2% or less. Nothing on the label narrows it further, and under the US alternative scheme these four may or may not be in order among themselves.

Our reading of the published list against 21 CFR 701.3. The bound holds under either US scheme and under the EU rule, because an ingredient printed below a 2% ingredient is either a lower-weight ingredient in a descending run or a member of the under-1% group. The one exception would be a color additive, which both systems allow to be placed last whatever its amount. This formula contains none.

Now set that against the marketing. Paula’s Choice names three key ingredients on that page, and one of them is green tea, which appears in the list as Camellia Oleifera at position six. The list tells you green tea is present at 2% or less. It does not tell you whether that is 1.5% or 0.001%, and there is no legitimate way to find out from the label. This is not an accusation of anything, since a small amount of an ingredient can be exactly the right amount. It is the limit of what you have been shown, and nothing more.

The same move works on any product that states a figure. The Ordinary’s Niacinamide 10% + Zinc 1% puts niacinamide second of eleven, behind water, which is roughly what 10% of something in a thin serum ought to look like. Where a brand states no figure at all, as CeraVe does with its Moisturizing Cream, you get order and only order, and no amount of confidence on the internet converts that into percentages.

If it is also a drug, the order changes

This is the exception most likely to catch a careful reader out, because it covers some of the most discussed products on the market: every sunscreen sold in the United States, and most acne and dandruff treatments there.

A product can be a cosmetic and an over-the-counter drug at the same time. When it is, 21 CFR 701.3(d) hands the labeling over to the drug rules, and 21 CFR 201.66 says this about the panel:

“If the product is an OTC drug product that is not also a cosmetic product, then the inactive ingredients shall be listed in alphabetical order. If the product is an OTC drug product that is also a cosmetic product, then the inactive ingredients shall be listed as set forth in § 701.3(a) or (f) of this chapter”.

And about the active ingredients, in the same section: “If the OTC drug product contains more than one active ingredient, the active ingredients shall be listed in alphabetical order.”

So on a sunscreen bottle, the Drug Facts panel lists the UV filters alphabetically, not by how much of each there is. Avobenzone appearing first tells you nothing except that A comes before H, O and Z. The compensation is that the panel states each active’s percentage outright, which is more than a cosmetic list ever gives you. The inactive ingredients underneath revert to the cosmetic rule, descending order or the optional 1% grouping, exactly as on any other cosmetic.

Read a sunscreen panel as though it were a cosmetic list and you will reach a confident, tidy and wrong conclusion about which filter dominates the formula.

Three things that are not in order at all

Beyond the drug case, both systems carve out categories that sit outside descending order. A list that looks odd at the end is usually obeying one of these.

• Color additives. Under the US alternative scheme they form a third group, listed last, “without respect to order of predominance”, whatever their concentration. The EU is similar: colorants other than hair colorants “may be listed in any order after the other cosmetic ingredients”. Both systems also let a range of shades share a single list. The EU allows every shade’s colorants to be printed on all of them, flagged with “may contain” or the symbol “+/-”, and 21 CFR 701.3(g) lets a US declaration “include an ingredient not in the product” under that same “may contain” phrase, for color matching and for shaded products. On a foundation or a lipstick, in either market, some of what is printed is not in your bottle at all.
• Fragrance. The US rule allows the whole category to appear as the single word “fragrance”. The EU requires the terms “parfum” or “aroma”, with named allergens from the Annex III list declared separately alongside. Either way, one entry can stand for dozens of individual substances, and since it is declared as a single ingredient it takes its place in the order by the weight of the whole composition, not by any one component.
• Nanomaterials. The EU is explicit: “All ingredients present in the form of nanomaterials shall be clearly indicated” and that the name be “followed by the word ‘nano’ in brackets”. We searched the whole of 21 CFR Part 701 and Part 720 and found no equivalent US requirement, so a US label does not have to tell you, and mostly does not.

There is one more absence worth knowing about. A US company that persuades the FDA an ingredient is a trade secret may leave it off the list entirely and print the phrase “and other ingredients” at the end instead. The mechanism is in 21 CFR 720.8. The EU has no equivalent. Article 19 offers no route for leaving an ingredient off the list, and a search of the full consolidated Regulation for the words confidential and trade secret returns nothing at all; its one mention of commercial secrecy, in Article 21, concerns what a company must publish beyond the label, not what it may leave off it.

When an ingredient’s own legal ceiling tells you something

Occasionally the law does your arithmetic for you. Some ingredients carry a hard maximum concentration, so seeing one on a label puts a ceiling on it without the brand saying a word. This works properly in the EU and GB, where the maxima are written into the annexes of the Regulation, and it is the most reliable read you will get from a list that states no figures.

• Phenoxyethanol, capped at 1,0 %. Annex V, entry 29, the preservatives list. No product-type restriction and no conditions attached.
• Salicylic acid, other than as a preservative: 3,0 % in rinse-off hair products, 2,0 % in most other products, and 0,5 % in body lotion, eye shadow, mascara, eyeliner, lipstick and roll-on deodorant. Annex III, entry 98, which adds: “These levels are inclusive of any use of salicylic acid.”
• Salicylic acid used as a preservative, 0,5 % (acid). Annex V, entry 3.

Read from the consolidated text of Regulation (EC) No 1223/2009 as at 1 May 2026. The percentages are written with a comma in the original, which is how the Official Journal prints a decimal point.

Two useful consequences follow. Phenoxyethanol is capped at 1% in Europe, so on a European label it works as a marker: anything printed below it, colorants aside, is at 1% or less. And the Paula’s Choice exfoliant above sits exactly on the European ceiling for a product of its kind, so its 2% is the most the law allows for that use, not a figure the brand had room to raise.

The United States does not work this way for cosmetics. FDA’s own summary is that cosmetic products and ingredients, other than color additives, “do not need FDA approval before they go on the market”, and the short list of substances restricted by regulation includes none of the common preservatives. What exists instead is the Cosmetic Ingredient Review, an industry-funded expert panel whose recommended maximum concentrations carry no force of law. A ceiling you can rely on in Europe is only a convention in America, even when the product in your hand is the same one. The exception is the one this article has already met: where an ingredient is a drug active, the US does set binding numbers. The acne monograph at 21 CFR 333.310 permits “Salicylic acid, 0.5 to 2 percent”, so the 2% in the worked example sits at the top of the American range and on the European ceiling at once, and we cannot tell you which of the two the brand had in mind.

What the list cannot tell you

This is the honest half, and it is why we never claim more from a teardown than a teardown can carry. None of the following is on the label, and none of it can be worked out from the order.

• The actual percentage of anything
• pH
• Free-acid value
• Whether an active is encapsulated
• Stability over the product’s life
• The grade or purity of a raw material
• Whether the website list matches the box

pH and free-acid value. For an acid, how much of it is in its active free form depends on the finished product’s pH, and pH is not a declared item anywhere. Two exfoliants with identical lists can behave quite differently. The point is not new: the Cosmetic Ingredient Review panel’s 1998 conclusion, quoted in FDA’s guidance on labeling for alpha hydroxy acids, ties its safety finding to both numbers at once, holding that glycolic and lactic acid and their salts and simple esters are “safe for use in cosmetic products at concentrations ≤10%, at final formulation pH ≥3.5”. That is the panel’s wording quoted by FDA rather than FDA’s own finding, and the guidance is a recommendation rather than a binding limit. It still makes the point: a percentage on its own was never considered enough to describe the product.

Encapsulation. INCI names a substance, not the way it has been packaged inside the formula. Retinol is the same word on the label whether the retinol is free or held in a delivery system, and the difference is not small. One 2024 study of silica microparticle encapsulation puts it in one sentence: “Encapsulation allowed an increase in the minimal skin cytotoxic concentrations of retinol from 0.04 μg/mL to 1.25 mg/mL without skin sensitization.” Whatever you make of a single cell study, two products declaring the same ingredient at the same amount are not necessarily doing the same thing.

Purity and stability. Both are real regulatory concerns and both live somewhere you cannot see. In the EU they belong in the Product Information File, which the responsible person must keep available to regulators rather than to you. Actual concentrations go the same way. The EU requires a frame formulation to be filed centrally so that poison centers can treat someone in an emergency, and that database is not public. There is one door left ajar: Article 21 of the same Regulation obliges a company to make the product’s qualitative composition accessible to the public, and its quantitative composition too for any ingredient classified as hazardous under the EU’s classification rules. That is a narrow door, it is not the label, and you have to go and ask. For everything else, somebody knows the percentages and it is neither you nor us.

And the list you are reading may not be the list on the box. Every brand we looked at says so in its own words. Paula’s Choice writes that it “cannot guarantee that these lists are error-free” and points you at the package. CeraVe asks you to “refer to the ingredient list on your product package for the most up-to-date list”. The Ordinary warns that its published list “may vary from the box of the product depending on time and region of purchase”. Reformulation is constant and websites lag behind it. For anything that matters, read the box in front of you.

How to read a list in four steps

Put together, the method is short.

• Find an anchor. Any stated percentage, on the front of the pack or in the product name, fixes one position in the list. Everything below it is at or under that figure. Without an anchor you have order and nothing else.
• Locate the tail. Preservatives, chelators, gums and fragrance cluster at the bottom. In the EU, phenoxyethanol is capped at 1% and marks the line usefully. In the US, treat the tail as small and unstated rather than as proof of anything.
• Check what kind of label it is. A Drug Facts panel means the actives are alphabetical and carry stated percentages, and only the inactives below them are in order of amount.
• Stop where the evidence stops. The list cannot give you pH, free-acid value, encapsulation, stability or grade. If a comparison turns on one of those, the ingredient list cannot settle it, and neither can anyone quoting it at you.

There is no product to recommend at the end of this one and no affiliate link in it. The point of the piece is a method you can use on any label, including all the ones we will never write about.

Frequently asked questions

References

• US Code of Federal Regulations, 21 CFR 701.3, Designation of ingredients. ecfr.gov. Read from the eCFR versioner API on 13 September 2026, title 21 current as of 10 September 2026. The section itself was last amended at 81 FR 49897, 29 July 2016.
• US Code of Federal Regulations, 21 CFR 201.66, Format and content requirements for over-the-counter (OTC) drug product labeling. ecfr.gov. Same fetch.
• US Code of Federal Regulations, 21 CFR 720.8, Confidentiality of statements. ecfr.gov.
• Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products (recast), Article 19 and Annexes III and V. Consolidated text as at 1 May 2026. eur-lex.europa.eu.
• Regulation (EC) No 1223/2009 as retained in Great Britain, Article 19. legislation.gov.uk. Checked clause by clause against the EU text.
• US Food and Drug Administration. Guidance for Industry: Labeling for Topically Applied Cosmetic Products Containing Alpha Hydroxy Acids as Ingredients, January 2005. fda.gov. The concentration and pH figures quoted in this article are from the Cosmetic Ingredient Review Expert Panel’s 1998 report as quoted within that guidance.
• US Food and Drug Administration. Prohibited and Restricted Ingredients in Cosmetics. fda.gov.
• Costa, J. R. et al. (2024). Silica Microparticles from Sugarcane By-Products as an Encapsulation System for Retinoids Aimed at Topical Sustained Release. International Journal of Molecular Sciences, 25(6), 3215. 10.3390/ijms25063215. Open access.
• Paula’s Choice. SKIN PERFECTING 2% BHA Liquid Exfoliant, ingredient list as published by the manufacturer. paulaschoice.com. Read 13 September 2026.
• The Ordinary. Niacinamide 10% + Zinc 1%, ingredient list as published by the manufacturer. theordinary.com. Read 13 September 2026.
• CeraVe. Moisturizing Cream, ingredient list as published by the manufacturer. cerave.com. Read 13 September 2026.