Non-comedogenic, hypoallergenic, dermatologist-tested: words with no legal definition

Published 6 August 2026Zane Hitchcox, editor

A front-of-pack claim is not a lie merely because it is undefined. The problem is narrower: each phrase describes a real technical operation, the operation is much weaker than the phrase implies, and the gap between the two is where the marketing value sits.

What the United States actually defines

The Food and Drug Administration publishes guidance on exactly five cosmetic label claims: "alcohol free", "cosmeceutical", "cruelty free", "hypoallergenic" and "organic".⁸ Not non-comedogenic, dermatologist-tested, clinically proven, paraben-free, sulfate-free, fragrance-free or pH-balanced. Part 700 of Title 21 of the Code of Federal Regulations, which carries FDA's cosmetic prohibitions, runs from § 700.3 to § 700.35 and defines none of them.³

New Zealand is the same picture through a different lens. Cosmetics here sit under the Environmental Protection Authority's Cosmetic Products Group Standard 2020 (HSNO approval HSR002552, in force 30 April 2021), an instrument about hazardous substances: ingredient prohibitions, concentration limits, hazard classification, warning statements — and a requirement that the label carry a list of ingredients.²⁸ Even in New Zealand, then, the regulated surface is the back of the pack. None of the marketing words appears anywhere in the instrument. Which agency regulates what explains why nobody vets these adjectives before a product ships.

What catches them afterwards is section 12A of the Fair Trading Act 1986, inserted on 17 June 2014, which makes it unlawful to make an unsubstantiated representation in trade — one for which the person "does not, when the representation is made, have reasonable grounds", and it bites "irrespective of whether the representation is false or misleading". But subsection (3) carves out any representation "that a reasonable person would not expect to be substantiated".¹³ That carve-out is where most of the front of the pack lives, and it is the reason an adjective is rarely worth a regulator's time.

Non-comedogenic: an assay developed on rabbit ears

What the shopper thinks it means: this will not block pores. What it is permitted to mean: anything the manufacturer decides. What would have to be true: that the finished formula, not its ingredients, was tested on human skin prone to comedones and produced fewer microcomedones than a control.

The claim descends from a specific laboratory method. In 1979 A. M. Kligman and T. Kwong published a simplified comedogenic assay in the British Journal of Dermatology: test materials applied for two weeks to the external ear of a rabbit, the excised tissue then immersed in water at 60 °C to yield a sheet of epidermis with microcomedones attached and countable under a stereomicroscope.⁴ It was fast and cheap, and the ingredient rating lists still circulating online — the ones scoring an oil from 0 to 5 — trace back to work of that kind.

The method was under attack within three years. Reviewing it in the Journal of the American Academy of Dermatology in 1982, S. B. Frank reported "the absence of correlation with experience in the human" and concluded that the inferences a clinician could draw from it were seriously limited.⁵ In the same year Mills and Kligman published a human version and found the rabbit model more sensitive than the human one: substances only weakly comedogenic in the rabbit were probably safe on human skin, with the possible exception of acne-prone people.⁶ A screen that over-calls is not useless, but it is not a licence to label finished products. The more damaging finding came later, and it is about formulas rather than ingredients.

So the ingredient list is the wrong unit of analysis.⁷ A formula containing a "comedogenic" oil may not be comedogenic, and a formula of blameless ingredients may still break someone out. "Non-comedogenic" is not false. It is unfalsifiable as printed, because it does not say what was tested, on whom, or against what.

Hypoallergenic: the one word a regulator defined, and lost

This is the only term on the list with a litigation history, and the history explains the vacuum.

FDA proposed a rule on 25 February 1974: a cosmetic could be designated "hypoallergenic" only where scientific studies in human subjects showed that its rate of adverse reactions was significantly less than that of reference products, and the manufacturer was responsible for carrying out the tests.¹ The final order was signed on 29 May 1975 and published as 21 CFR 700.100 on 6 June 1975. Two details of it are worth keeping, because nothing since has come close. "Reference products" meant similar-use competitive products in the same category representing a 10% market share — the claim had to be earned against products that were actually selling. And the finished regulation required the word on the pack to be followed by the phrase "less likely to cause adverse reactions than some competing products".²

Almay and Clinique sued on 15 July 1975. The District Court for the District of Columbia granted FDA summary judgment; the Court of Appeals for the D.C. Circuit reversed. In Almay, Inc. v. Califano, 569 F.2d 674, argued 9 June 1977 and decided 21 December 1977, the court found the administrative record could not support the comparative definition FDA had chosen. The only bases in that record, it held, were a dictionary that did not employ the chosen definition, an American Medical Association report recommending against any use of the word, and a Federal Trade Commission survey "the unreliability of which is apparent on its face". The Commissioner's action was arbitrary and capricious; the judgment below was vacated and the case remanded with instructions to grant the manufacturers declaratory relief.²

Nothing replaced it. FDA's position today is blunt: "There are no Federal standards or definitions that govern the use of the term 'hypoallergenic.' The term means whatever a particular company wants it to mean," and manufacturers need not submit substantiation to the agency.¹ The section number is simply gone from the Code of Federal Regulations.³

Europe is the exception. Annex IV of the Technical Document on Cosmetic Claims, applicable since 1 July 2019, permits the claim only where a product "has been designed to minimize its allergenic potential", requires scientifically robust and statistically reliable evidence of very low allergenic potential, continuously updated, and requires total avoidance of substances identified as skin sensitisers by the SCCS, by other official risk-assessment bodies, by CLP classification, by the company's own complaint data, by the literature, or for which sensitisation data are simply missing.¹⁸ It adds that the claim does not guarantee absence of risk and the product must not imply that it does.

Dermatologist-tested says a dermatologist was in the room

It does not say what the dermatologist concluded. There is no defined protocol, no minimum sample, no requirement that the result was favourable and no requirement to publish. "Dermatologist-recommended" asserts a fact about a population of doctors without saying how many, chosen how, or asked what. Dermatologists have put the question in print: Lohman, Lio and Xu asked whether the label is meaningful in the Journal of the American Academy of Dermatology in 2018.⁹

What is measurable is the price.

Two consumer regulators reach the same rule from opposite ends of the world: state a level of proof and you must hold it. The Commerce Commission puts it this way — "When a particular level of substantiation for a claim is expressly stated, such as 'tests prove' or 'doctors recommend', the claim must be supported by the level of substantiation communicated to consumers."¹² The FTC's formulation is that marketers "must have at least the level of support that they claim to have".¹¹

Clinically proven is the claim that raises its own bar

"Clinically proven" is not defined by any cosmetic regulator, but unlike the others it invites a specific enforcement standard, because it is an express statement about the evidence. The FTC's Health Products Compliance Guidance of December 2022 sets that standard as competent and reliable scientific evidence: substantiation of health-related benefits will generally need to be randomised, controlled human clinical testing; animal and in vitro work may support but cannot alone substantiate; and surveys of consumer experience are "never sufficient". Imagery can convey the claim without words — a brochure of white coats, microscopes and stacked journals likely conveys an implied claim that a product has been clinically proven. Section 12 of the FTC Act reaches false advertisements for cosmetics specifically.¹¹

There is a second trap. In the United States a product's intended use decides its legal category, and a claim to affect the structure or any function of the body makes it a drug under section 201(g)(1) of the Federal Food, Drug, and Cosmetic Act.¹⁶ "Cosmeceutical", the industry word for the space between, "has no meaning under the law".¹⁵ A brand that says too much about mechanism risks being told it has been selling an unapproved drug, which is one reason cosmetic claims are so carefully vague. The gap between what a cream may legally claim and what a topical product can physically do is a different gap, and the two are often confused.

Paraben-free: the substitution nobody priced

This is the claim where the evidence has moved furthest from the marketing, and the honest account is uncomfortable in both directions.

The European Union did restrict parabens, and did so on the record. Commission Regulation (EU) No 358/2014 of 9 April 2014 moved isopropylparaben, isobutylparaben, phenylparaben, benzylparaben and pentylparaben into Annex II of the Cosmetics Regulation — prohibited — not because harm was shown but because, as recital 7 records, industry submitted limited or no information for their safety evaluation, so the human risk could not be evaluated at all.¹⁹ Commission Regulation (EU) No 1004/2014 of 18 September 2014 then capped butylparaben and propylparaben at 0.14% as acid for the sum of their concentrations, and banned them in leave-on nappy-area products for children under three, after the Scientific Committee on Consumer Safety concluded their use was safe up to 0.19% as esters.²⁰ Methylparaben and ethylparaben were left where they were, the SCCS having confirmed them safe at the maximum concentrations already authorised.¹⁹ "Parabens" is not one substance with one verdict — five prohibited for want of data, two capped, two confirmed safe — and a blanket avoidance claim flattens all of that into a single word.

On allergy the picture is clearer, and it runs against the label.

The review does not name the replacement in its abstract; it says only that parabens have been replaced "with preservatives having far greater allergenic potential".²² The best-documented candidate is methylisothiazolinone. The SCCS concluded on 12 December 2013 that for leave-on products, including wet wipes, no safe concentration of it for the induction or elicitation of contact allergy had been adequately demonstrated; Commission Regulation (EU) 2016/1198 of 22 July 2016 accordingly banned it from every leave-on cosmetic, with only compliant products permitted on the Union market from 12 February 2017.²¹ Allowable concentrations diverged between Europe, Canada and the United States, and the patch-test record of the years either side is about as close to a natural experiment as cosmetic regulation gets.²³

North American rates have since turned. The NACDG's 2021–22 series reports methylisothiazolinone positivity of 11.5%, down from the 2017–18 peak, and its authors write that the epidemic "appears to continue its descent".²⁴ That the paraben-free label caused the isothiazolinone epidemic is not established; the relationship is temporal and the substitution motive is reported rather than measured. What is established is that the substitute produced double-digit patch-test positivity against a paraben rate the 2019 review calls low and remarkably stable over decades, and that a regulator had to remove the substitute from an entire product class where parabens were merely capped.

FDA's position on the underlying safety question is that it does not have information showing that parabens as used in cosmetics affect human health, and one of the questions it says it is weighing is: "What are the hazards and risks of not using parabens?"²⁹ The label does not answer it.

Sulfate-free: a real difference, an overstated conclusion

Sodium lauryl sulfate and sodium laureth sulfate are anionic detergents, and detergents remove lipid, which is what they are for. Formulators do treat them as harsher than the amphoteric surfactants used beside or instead of them: cocamidopropyl betaine is described in the dermatology literature as having been adopted increasingly "because it induces relatively mild skin irritation".²⁵ What "sulfate-free" does not tell a reader is the concentration, the contact time, or what took the sulfate's place.

The substitute has its own file. Cocamidopropyl betaine was named the American Contact Dermatitis Society's Allergen of the Year in 2004, with contact sensitisation prevalence estimated between 3.0% and 7.2% and the manufacturing impurities amidoamine and dimethylaminopropylamine implicated as the actual sensitisers.²⁵ In the 2021–22 NACDG series, dimethylaminopropylamine was among the allergens whose prevalence rose significantly.²⁴ This is the paraben pattern again in a different aisle.

There is one substantive argument for avoiding ethoxylated surfactants, and it is not the one on the bottle. 1,4-dioxane is a manufacturing byproduct that can occur in trace amounts in ingredients identifiable by "PEG", "polyethylene glycol", "-eth-" or "-oxynol-". A 2016 National Toxicology Program report found it "reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals" — while noting that the human epidemiological data are not adequate to evaluate the relationship between exposure and cancer in people. The SCCS regards trace levels at or below 10 ppm as safe, and in a 2018 FDA survey of 82 children's products only two — about 2% — exceeded that.²⁶ That is a different argument from the one "sulfate-free" implies, and a weaker one than the phrase suggests.

Fragrance-free and unscented are not the same word

Neither is defined, and they do not mean the same thing. FDA states the trap in its own words: "Even some products labeled 'unscented' may contain fragrance ingredients. This is because the manufacturer may add just enough fragrance to mask the unpleasant smell of other ingredients, without giving the product a noticeable scent."¹⁴ A masking fragrance is still a fragrance to an immune system.

"Fragrance-free" is the stronger phrase and is also undefined, which is why 45% of the best-selling moisturisers claiming it in the 2017 census carried a fragrance cross-reactor or a botanical ingredient.¹⁰ Part of the mechanism is a labelling rule: under 21 CFR 701.3(a) fragrance may be declared simply as "fragrance",³ while essential oils and botanical extracts are declared under their own names and are not read as fragrance at all — though they are among the commonest causes of cosmetic contact allergy. Hydroperoxides of linalool were positive in 10.1% of patients in the 2021–22 NACDG series, behind only nickel and methylisothiazolinone.²⁴

pH-balanced: a real number, attached to nothing

Skin surface pH is a genuine measurement with a genuine literature. The claim is the empty part, because it never states the number it is balanced to.

A product at pH 5.5 and a product at pH 7 may both print "pH-balanced", against a natural surface value the best available estimate puts near 4.7.²⁷ The claim would become useful the moment it printed a figure, which is presumably why it does not — and that is the general rule for the front of a pack. The informative surface is the back, where the ingredient declaration is legally specified in a way the adjectives are not.

The European Union is the only place that argues back

Commission Regulation (EU) No 655/2013 of 10 July 2013 lays down six common criteria for the justification of cosmetic claims — legal compliance, truthfulness, evidential support, honesty, fairness and informed decision-making — and, being a Regulation, it is directly binding across the Union. Its fairness criterion is the load-bearing one: claims "shall be objective and shall not denigrate the competitors, nor shall they denigrate ingredients legally used".¹⁷ The interpretive layer sits in the Technical Document on Cosmetic Claims agreed by the Sub-Working Group on Claims on 3 July 2017, whose Annexes III and IV apply from 1 July 2019. That document is careful about its own status: it is not a Commission document, is not legally binding, and is a collection of best practice for case-by-case application by member states, whose authorities and courts decide.¹⁸ The caveat is routinely dropped in summaries of it.

Annex III applies each criterion to "free from" claims, and the results are unusually specific. Under truthfulness, "free from formaldehyde" is not allowed if the product contains a formaldehyde-releasing ingredient such as diazolidinyl urea. Under honesty, "free from allergenic/sensitizing substances" is not allowed at all, because complete absence of allergic risk cannot be guaranteed. Under legal compliance, a claim cannot advertise the absence of something already banned — the example given is "free from corticosteroids".¹⁸

Then fairness, which is the part with teeth. "Free from" claims should not be allowed where they imply a denigrating message, particularly where they rest on a presumed negative perception of an ingredient's safety. The worked example is unambiguous: certain parabens are safe when used in accordance with the Cosmetics Regulation, all cosmetic products must be safe, and so "free from parabens" "should not be accepted, because it is denigrating the entire group of parabens". The same reasoning is extended to phenoxyethanol and triclosan.¹⁸

The EU still permits "free from" claims that serve a real choice: "free from alcohol" on a family mouthwash, "free from animal-derived ingredients" for vegans, "free from acetone" in nail polish for people who dislike the smell.¹⁸ The distinction is between helping a reader select and teaching a reader to fear. Neither the United States nor New Zealand has written anything comparable down.⁸²⁸ What "natural" and "clean" are permitted to mean is a related question with a similar answer.

What a reader can do with all of this

Treat each phrase as a statement about marketing rather than about the product, and read the ingredient declaration for anything that matters. Where the concern is allergy rather than irritation, the decisive information is a named substance and a patch test performed by a clinician, not an adjective on a carton. A persistent rash is a reason to see a doctor rather than to change brands.