Cottonseed Oil
Cottonseed oil is rated Caution, and the number behind it is real but thin. Fulton's 1989 rabbit-ear assay scored it 3 of 5 — a grade he himself filed as "borderline," not positive — and that single reading is the whole of the measured evidence. The one other independent rabbit lab that worked the same 0-to-5 scale never tested it, and we found no study that counted comedones on human skin after using it. Caution reflects one borderline result with nothing to confirm or contradict it.
Fulton 1989 scored it 3 of 5, borderline on his own key. One rabbit assay, no replication found.
What it is
The oil pressed from the seeds of the cotton plant, Gossypium — historically a byproduct of the cotton and textile industries rather than a crop grown for its oil. It is a linoleic-rich vegetable oil that is also, unusually for a seed oil, high in the saturated fatty acid palmitic. Published analyses of it differ enough with species, cultivar, extraction and refining that we are not going to print one set of percentages as though a single figure existed. Crude cottonseed oil also contains gossypol, a yellow polyphenol native to the plant, which refining reduces to trace levels. The Cosmetic Ingredient Review's 2017 assessment of plant-derived fatty acid oils covers cottonseed among them and concludes those oils are safe as used in cosmetics — a safety finding, which is a different question from the one this page asks. We describe the composition here only to say what the material is; it is not, on this page, an argument about pores. On a label it appears as Cottonseed Oil, or in INCI form as Gossypium Herbaceum (Cotton) Seed Oil — a name that specifies a cotton species where Fulton's row specifies none.
Why we rate it Caution
We rate it Caution, and the rating rests on a single legacy rabbit-ear score with nothing beside it. Fulton's 1989 table — the source nearly every comedogenic number online descends from — prints Cotton seed oil, as two words, at 3, in section VI, "Oils." We read the row off a render of the journal scan rather than off a list quoting it. What a 3 meant to Fulton is the part the charts drop: his own key reads "a minimal grade of 0 to 1 is not considered significant. Grade 2 to 3 is borderline. However, a grade of 4 to 5 is uniformally reproduceable and considered positive." So cottonseed oil's 3 sits at the top of the borderline band — above "not significant," but short of the "positive" grades. It is printed as a bare 3, with none of the parenthetical second figure Fulton used for oils whose refined grade tested lower — avocado 3(2), mink 3(2), olive 2(1) — so he recorded one number for it and no improved value. That is not unusual in the section: corn, soybean, evening primrose and shark liver oil are bare 3s too. The section heading carries his footnote, "Results depend on source of raw material," which applies to every oil and butter row in it, and Fulton named neither species, supplier nor grade for what he tested. The point that separates cottonseed oil from the oils where two labs agree, or disagree, is that we found no second reading of it anywhere in the legacy corpus. Morris and Kwan, in the Journal of the Society of Cosmetic Chemists in 1983, ran the only other independent rabbit-ear assay on the same 0-to-5 scale, and it is genuinely independent of Fulton — the same paper contradicts him in print on sodium lauryl sulfate. But their vegetable-oil set was nine oils — olive, avocado, castor, corn, sesame, safflower, peach kernel, grape seed and sweet almond — and cottonseed was not one of them. Fulton's own earlier 1984 paper has no cottonseed row either. So the 3 is neither confirmed by a second reading nor pulled down by one; it stands alone. Caution reflects that one borderline result, taken at face value.
What the evidence doesn’t tell you
We identified no human comedogenicity study of cottonseed oil — no count of comedones on a face, or a back, after using it. Human topical work with the oil does exist, and it measured other things: a double-blind pilot trial published in 2015 used cottonseed oil as the placebo, applied twice daily to the breast or chest wall through a course of radiotherapy in 45 patients, and scored radiation dermatitis and quality of life. It counted no comedones, and it was not designed to. Everything the rating leans on happened in one rabbit-ear assay: Fulton's, three rabbits, roughly 10% in propylene glycol, follicular keratosis scored by microscope. Fulton called his own 220-row survey "not at all definitive but simply designed to stimulate research," and warned that the rabbit ear is sensitive enough that "not everything that irritates this model will also irritate human skin." The source-dependence caveat has unusual force for this oil. Fulton's oils footnote — "Results depend on source of raw material" — is not a formality here: published analyses of cottonseed oil differ with species, cultivar and refining, and Fulton named none of the three for his sample. A single grade from one batch in the 1980s is a weak promise about the bottle in hand, and with only that one grade on record there is no range to reason across. The footnote makes grade dependence plausible; it does not show that a more refined cottonseed oil would have tested lower, because Fulton never printed the pair. The composition invites a tidy story, and we are going to leave it uninvited. Cottonseed oil carries more palmitic acid than most seed oils, and it would be easy to spin that saturated fraction into an explanation for the borderline score — just as some ingredient blogs spin its omega-6 content the other way, into inflammation and breakouts. Neither version is backed by a comedogenicity measurement of cottonseed oil. A mechanism that would explain a result is not additional evidence for it, and we are not going to write one as though somebody had run the study. Two things that are not comedogenicity data, flagged so they are not mistaken for it. The CIR's 2017 assessment concludes the plant-derived fatty acid oils are safe as used in cosmetics — but safety is a different question from follicular plugging, and the report says nothing about comedogenicity. And the field-wide caveat, from a 2025 review in JAAD Reviews surveying the literature from 1972 on: no standardised comedogenicity test exists, and "non-comedogenic" is an unregulated label.
Where you’ll see it
On a label it appears as Cottonseed Oil or Gossypium Herbaceum (Cotton) Seed Oil. The Cosmetic Ingredient Review lists the plant-derived fatty acid oils, cottonseed included, as skin-conditioning, emollient and occlusive agents, so the places to expect it are the ordinary emollient ones — creams, lotions, soaps, cleansers — which is what a listed function implies rather than a market survey we have read. It has a long parallel life as a food and frying oil. Cosmetic and food grades are normally refined, which is what takes the gossypol and pigments down; we did not establish that no minimally processed grade is ever sold for use on skin. Fulton's caveat is that the source and refining of the raw material can move the result, not that the grades are separate ingredients.
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 our legacy score and of nearly every comedogenic number in circulation. Method: the ingredient at 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. Read off a render of the journal scan, not off a list quoting it. Its Table I, section VI "Oils," prints Cotton seed oil at 3 — a bare 3, with no parenthetical "refined oil" figure of the kind it gives for avocado 3(2), mink 3(2) and olive 2(1). It supplies the grade key the lists omit — 0 to 1 "is not considered significant," 2 to 3 is "borderline," 4 to 5 is "considered positive" — and the footnote that sits on the section heading, and so on every oil and butter row in it, "Results depend on source of raw material." Fulton named no species, supplier or grade for the oil he tested, and called the survey "not at all definitive."
- Morris WE, Kwan SC. "Use of the rabbit ear model in evaluating the comedogenic potential of cosmetic ingredients." J Soc Cosmet Chem 34:215–225 (1983) The only other independent rabbit-ear assay on the same 0–5 scale — three rabbits, ear canal, undiluted unless stated, 14 applications, microscopic grading — and it is genuinely independent of Fulton, contradicting him in print on sodium lauryl sulfate. Cited here for what it does NOT contain: its vegetable-oil set is nine oils (olive, avocado, castor, corn, sesame, safflower, peach kernel, grape seed, sweet almond), and cottonseed is not among them. So there is no second reading of this oil to confirm or contradict Fulton's 3 — the reason this page can say the score stands alone.
- Rollmann DC, Novotny PJ, Petersen IA, Garces YI, Bauer HJ, Yan ES, Wahner-Roedler D, Vincent A, Sloan JA, Laack NNI. "Double-blind, placebo-controlled pilot study of processed ultra emu oil versus placebo in the prevention of radiation dermatitis." Int J Radiat Oncol Biol Phys 92(3):650–658 (2015) A randomised double-blind pilot trial in 45 patients, 42 evaluable, undergoing radiotherapy to the breast or chest wall. Cottonseed oil was the PLACEBO — the trial was testing emu oil — applied twice daily through the course of treatment. Endpoints: Skindex-16 quality-of-life scores, maximum grade of radiation dermatitis by CTCAE 3.0, a skin toxicity assessment tool and a symptom diary. Cited here only because it is topical human data on this oil, and because it is not comedogenicity data: it counted no comedones, took no follicular biopsies, and studied irradiated chest skin rather than faces. It shows the oil has been put on human skin under trial conditions. It cannot tell you what it does to a pore.
- Burnett CL, Fiume MM, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler D, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Andersen FA. "Safety Assessment of Plant-Derived Fatty Acid Oils." Int J Toxicol 36(3 Suppl):51S–129S (2017) An independent Cosmetic Ingredient Review Expert Panel safety review covering 244 plant-derived fatty acid oils, cottonseed (Gossypium) oil among them — not a comedogenic list and not downstream of Fulton. Free access; read for what it can support: the material's fatty-acid character (linoleic-rich, unusually high in palmitic for a seed oil), its cosmetic functions (skin-conditioning, emollient, occlusive), the difference between crude and refined oil in gossypol content, and the Panel's conclusion that these oils are safe as used. It assesses safety, not comedogenicity, and says nothing about pores. It is also not the only CIR document on this ingredient — cottonseed oil has its own earlier cottonseed-specific assessment, which we have not read and do not cite here.
- "Comedogenicity in cosmeceuticals: a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the whole field, covering the literature 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. Finds that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. Cited for the field-wide caveat, not for anything specific to cottonseed oil.
- The circulating comedogenic-rating charts — acne.org's comedogenic list, and the ingredient charts generally Where a reader will have met cottonseed oil's "3," and cited for genealogy rather than as evidence. What we checked, and only what we checked. acne.org's comedogenic list now describes itself as synthesising 11 rabbit-ear and human studies under a multi-study rule, not as republishing one paper, and we did not find cottonseed oil rated on it at all. The charts that do print a 3 for cottonseed oil — Wholesale Supplies Plus and Simple Pure Beauty among them — give no source for the individual ratings, and at least one files the 3 under "Moderate," which is Fulton's number with Fulton's own word for it, "borderline," removed. Matching numbers do not establish who copied whom, so we do not assert a chain. What we can say is that none of these charts is a measurement.
Others in the same family
Oils 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 oils as a family ›
Last reviewed 2026-08-01 · How we decide