Retinol
Retinol is rated Clear, but that is an inference rather than a measurement: no comedogenicity assay we can find has tested retinol itself, and the one number that circulates near it belongs to retinyl palmitate, a different molecule.
No assay we can find. The AAD's recommended retinoids are prescription drugs, not this.
What it is
Retinol is vitamin A in its alcohol form, and the best-known cosmetic retinoid. Formulators reach for it to address photoaging, fine lines and skin texture; on a label it is simply Retinol. In the skin it is not the active molecule but a precursor to one: it is converted in two steps — retinol oxidised to retinaldehyde, then retinaldehyde to all-trans retinoic acid — into the biologically active form of vitamin A (Mukherjee et al. 2006). Retinoic acid itself is a prescription drug, tretinoin, and it is worth keeping that distinction in view on this page: the over-the-counter cosmetic ingredient is a precursor to that drug, not the prescription drug itself — milder in typical use, though cosmetic retinol can still be markedly irritating. The Cosmetic Ingredient Review's 2017 safety assessment of retinol and retinyl palmitate concluded the ingredients are safe in the present practices of use and concentration. Regulators cap the amount: under the EU's Commission Regulation (EU) 2024/996, vitamin A — retinol together with its acetate and palmitate esters — is limited to 0.05% retinol-equivalent in body lotion and 0.3% RE in other leave-on and rinse-off products. It is a safety conclusion, not a comedogenicity one — a distinction the rest of this page turns on.
Why we rate it Clear
We rate retinol Clear, at Low confidence, and the Low is the honest part. There is no legacy comedogenic score for retinol, because there is no assay of it that we have been able to find. Start with material identity, because it is where the circulating numbers come apart. Fulton's 1989 rabbit-ear survey is the primary source of nearly every comedogenic score in circulation. We read its Table I off a 400dpi render of the journal scan, row by row. It has no retinol row anywhere. What it does have, in its vitamins section, is "Vitamin A palmitate," graded 1-3*. That is retinyl palmitate — retinol esterified to palmitic acid, a larger molecule with the formula C36H60O2 — and it is not the same material as retinol. The asterisk is Fulton's own footnote, "results depend on source of raw material," and it should not be dropped: the two lists we hold that quote this row both print it as a bare "1-3." On Fulton's 0-5 scale, a 1 is "not considered significant" and a 2-3 is "borderline," so even that range, for that different molecule, straddles insignificant to borderline rather than resolving to anything. It is not retinol's number, and it cannot be promoted onto retinol. So "Clear" is an inference, and we would rather say that plainly than dress it up. It rests on two things, and neither is a measurement of this ingredient. The first is that the exact material was never tested — an absent score is not a zero, and we are not going to read one in. The second is the direction of the therapeutic evidence, which runs the opposite way from clogging: retinol converts in the skin to retinoic acid, and retinoic acid is comedolytic — topical retinoids are the mainstay of acne therapy precisely because they normalise follicular keratinisation and reduce the microcomedones that precede acne lesions (Leyden et al. 2017). But that is a drug acting as a drug, and comedolysis — dissolving a plug — is a different endpoint from a comedogenicity assay, which asks whether a material creates one. We are not going to launder a therapeutic result into a test score. The rating is Low-confidence because the thing it rates has not been assayed.
What the evidence doesn’t tell you
The central limit is the one the rating already concedes: we identified no comedogenicity assay of retinol itself, in Fulton 1989 or in the other numeric assays we hold. The verdict is an inference, not a reading, and it should be weighed as one. The 1-3* that circulates near retinol belongs to retinyl palmitate, a different molecule, and carries Fulton's "depends on source of raw material" caveat. It cannot be moved onto retinol — but the reverse move is just as unwarranted. Retinol being the gentler parent of a borderline-scoring ester does not make retinol a zero. We hold no number for it in either direction. The comedolytic evidence is evidence about drugs, not a comedogenicity test of a cosmetic. It describes prescription-strength retinoic acid and the topical retinoids used to treat acne; retinol is a precursor to that chemistry, not the same thing at the same strength. And the CIR conclusion that retinol is safe as used is a safety finding — it addresses irritation, sensitisation and systemic toxicity, and says nothing about pores. Safety is not comedogenicity. One thing complicates the reassuring reading, and we would rather name it than omit it. Starting a retinoid is commonly followed by a transient flare — the "retinization" or "purge" period — usually attributed to accelerated cell turnover bringing existing congestion to the surface rather than to the ingredient plugging follicles. That explanation is repeated in clinical practice more than it is firmly demonstrated, and the retinoid literature behind it (Leyden et al. 2017) concerns prescription retinoids used as acne drugs, not a defined retinol "purge." It is described mainly for the prescription retinoids and is reported as milder for retinol; it is not a comedogenicity measurement, and it is also not nothing. It is the reason "retinol breakout" gets searched, and we cannot rule out that some retinol products break some people out for reasons a rating of the isolated ingredient would not capture. Beyond that, no standardised comedogenicity test exists at all, and "non-comedogenic" is an unregulated label (JAAD Reviews 2025).
Where you’ll see it
On a label it appears as Retinol, most often in serums, night creams and eye creams — leave-on products, typically at low percentages, held under the regulatory caps above. Three near neighbours are worth keeping separate from it, because conflating them is exactly the error this page corrects. Retinyl palmitate and retinyl acetate are esters of retinol and appear under their own INCI names; retinaldehyde (retinal) is the one-step-further oxidation product. Of these, retinyl palmitate is the material Fulton actually tested — the source of the 1-3* — and it is not retinol. The word "retinol" on a label refers to one specific molecule, and only the ester beside it ever went into the rabbit's ear.
Sources
Each source says what it actually is. Several widely-cited “sources” for comedogenic ratings are republishing the same 1989 assay, and counting them as independent agreement is how a thin evidence base gets made to look thick.
- Fulton JE. "Comedogenicity and irritancy of commonly used ingredients in skin care products." J Soc Cosmet Chem 40:321–333 (1989) The primary source of nearly every comedogenic score in circulation: ingredient diluted to roughly 10% in propylene glycol, applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, follicles scored for keratosis on a 0-5 scale (0-1 "not significant," 2-3 "borderline," 4-5 "positive"). Read here off a 400dpi render of the journal scan rather than via a list quoting it. IT HAS NO RETINOL ROW. Its vitamins section prints "Vitamin A palmitate" at 1-3* — retinyl palmitate, a different molecule from retinol, with the asterisk meaning "results depend on source of raw material." Cited as the source of an absence and a near-miss row, not as evidence for a rating of retinol.
- Cosmetic Ingredient Review (Johnson W, et al.). "Safety Assessment of Retinol and Retinyl Palmitate as Used in Cosmetics." Int J Toxicol 36(5 suppl 2):51S–129S (2017) An industry-funded expert-panel SAFETY review — the Cosmetic Ingredient Review, convened by the cosmetics trade association (the Personal Care Products Council) — not a comedogenicity assessment and not downstream of Fulton. Cited for two things it does establish: the identity of retinol versus its palmitate ester, and the practices of use and concentration (leave-on cosmetics, low percentages). Its conclusion is that the ingredients are safe as used; safety addresses irritation, sensitisation and toxicity, and says nothing about follicular plugging. It is cited here precisely to mark that boundary, not to cross it.
- Mukherjee S, Date A, Patravale V, Korting HC, Roeder A, Weindl G. "Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety." Clin Interv Aging 1(4):327–348 (2006) A peer-reviewed review of topical retinoids, cited for one narrow, well-established fact: that retinol is a precursor, converted in the skin in two oxidation steps (retinol → retinaldehyde → retinoic acid) to the active form of vitamin A. It is a review, not a comedogenicity study, and it is used only for the metabolism, which is the reason the material on the label is not the active drug.
- Leyden J, Stein-Gold L, Weiss J. "Why Topical Retinoids Are Mainstay of Therapy for Acne." Dermatol Ther (Heidelb) 7(3):293–304 (2017) A review of topical retinoids in acne, cited for two things and characterised so neither is overread: that retinoic acid and the topical retinoids are comedolytic — they normalise follicular keratinisation and reduce microcomedones — and that starting a retinoid is commonly followed by a transient flare and irritation ("retinization"). Both describe drugs acting as drugs. Comedolysis is not the inverse of a comedogenicity score, and the flare is not a comedogenicity measurement; the paper is evidence about therapy, cited to say what it can and cannot tell us about a cosmetic precursor.
- "Comedogenicity in cosmeceuticals — a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the whole comedogenicity field, from 1972 onward. It is a synthesis of the legacy literature, not a new measurement, and independent of Fulton only in authorship, since the corpus it surveys includes his. Cited for the field-wide caveat: no standardised comedogenicity test exists, and "non-comedogenic" is an unregulated label. It sets the ceiling on how much any comedogenic number, present or absent, can be asked to carry.
Others in the same family
Actives behave similarly enough that the evidence for one is often wrongly read across to the others. These are its structural relatives, not a guess. What the evidence says about actives as a family ›
Last reviewed 2026-07-13 · How we decide