Glyceryl Stearate SE
Glyceryl Stearate SE is rated Caution — but the comedogenic number depends entirely on which grade a formula uses: Fulton's 1989 rabbit-ear assay scored the self-emulsifying "SE" grade 3 and the plain grade 1, and even the 3 sits in the band Fulton himself called borderline rather than positive.
The self-emulsifying (SE) form scores moderate; plain glyceryl stearate rates low.
Sources disagree: Only the self-emulsifying "SE" grade is flagged; non-SE Glyceryl Stearate is rated low. Comedogenicity depends on which grade a formula uses.
What it is
An emulsifier — the thing that keeps oil and water from separating in a cream. Glyceryl stearate is the monoester of glycerin and stearic acid; on its own it is a weak, "non-self-emulsifying" emulsifier that usually needs a partner to build a stable lotion. The "SE" grade is not a single pure molecule but a self-emulsifying commercial grade of that ester with a small amount of soap blended in. The Cosmetic Ingredient Review defines Glyceryl Stearate SE, in its ingredient table, as "a self-emulsifying grade of glyceryl stearate that contains some sodium and/or potassium stearate" — those stearate soaps are what let it emulsify an oil-in-water cream more readily on its own (performance still depends on the rest of the formula), and they make the SE grade anionic (negatively charged) where the plain ester is not. Reported use is common: the CIR's 2015 review counted roughly 1,400 formulations using the SE grade, second among this ingredient family only to plain glyceryl stearate itself. The distinction between the two grades is the whole reason this page exists, because the legacy literature scored them differently and the label names them differently. "Glyceryl Stearate SE" and "Glyceryl Stearate" are two separate INCI names with two separate entries on this site. Which one is printed on a product's ingredient list is the thing that decides which number applies.
Why we rate it Caution
We rate it Caution, at Low confidence, and the confidence is Low because the only comedogenicity evidence for either grade is two rabbit-ear assays from the 1980s. The primary number comes from James Fulton's 1989 survey, the source of most comedogenic scores in circulation. His table prints two distinct rows here, and they do not agree: "Glyceryl stearate SE" scores 3 for comedogenicity, and "Glyceryl stearate NSE" — the non-self-emulsifying plain grade — scores 1. Both are on his 0–5 scale. The method behind those numbers is the same one behind almost every number of this kind: the ingredient diluted to roughly 10% in propylene glycol, applied to the inner ear of a New Zealand albino rabbit, five days a week for two weeks, three rabbits per assay, the resulting follicular keratosis measured under a micrometer. Fulton's own key to his own scale is the part almost nobody quotes, and it matters more here than usual. In his words: "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." By that key, the plain grade's 1 is not significant, and the SE grade's 3 is the top of the borderline band — not a positive finding. So the Caution rests on a borderline score for the SE grade specifically, and it is worth being exact that "borderline" is the author's word, not "clogging." A second, genuinely independent assay exists, which is rare on this site. Morris and Kwan, in 1983 — six years before Fulton and in a different laboratory — tested glyceryl stearate at 50% in mineral oil and scored it 2 on the same 0–5 scale. That is a real, non-Fulton measurement, and it lands in the same borderline territory. But it does not settle the grade question, because Morris and Kwan did not record which grade they tested: their row reads "Glyceryl Stearate" with no SE or NSE designation, and they diluted it to half strength in mineral oil rather than testing it neat or in Fulton's propylene glycol. So it corroborates that glyceryl stearate is borderline in a rabbit ear; it cannot tell you whether the soap in the SE grade is what moved Fulton's number from 1 to 3. On that last point we are deliberately not going further than the data. Fulton printed a 3 for the SE grade and a 1 for the plain grade; the chemical difference between them is the added stearate soap; it is tempting to conclude the soap is the cause. Fulton did not say so — his paper offers no mechanism for these two rows — and we have found no study that isolates the soap's contribution. The honest statement is that the self-emulsifying grade scored higher than the plain grade in one 1989 assay, and that the reason is not established.
What the evidence doesn’t tell you
The direct evidence is two rabbit-ear studies and nothing else. The rabbit-ear assay has been questioned in the dermatology literature for decades: Draelos and DiNardo's 2006 paper in the Journal of the American Academy of Dermatology found that its results do not reliably transfer to human skin, and a 2025 review in JAAD Reviews concluded that no standardised comedogenicity test exists at all and that "non-comedogenic" is an unregulated label. Those are the reasons this rating carries Low confidence rather than more. The score is also a score for a fixed test condition, not for a product. Fulton applied the ingredient at roughly 10% in propylene glycol; Morris and Kwan applied it at 50% in mineral oil. A finished cream typically uses glyceryl stearate SE at a low percentage, inside a formula whose other ingredients, pH and structure all change how any single component behaves. A rabbit-ear grade is not a dose–response curve, and it is not a prediction about a specific lotion. We identified no human comedogenicity study of glyceryl stearate in either grade. The Cosmetic Ingredient Review has assessed both grades — and concluded they are safe for topical use — but that assessment is about safety, not pores: the words comedogenic, comedone, acne and follicle do not appear in its review of this ingredient. Safety and comedogenicity are different questions, and a clean safety record is not evidence either way about clogging. Finally, the grade ambiguity cuts both ways. Because Morris and Kwan did not state their grade, and because many products and databases list only "Glyceryl Stearate SE" without a certificate of analysis, the exact soap content of any given commercial SE material is not something a reader can verify from a label. The number on this page belongs to the material Fulton labelled "SE." Whether a given jar's SE grade matches his is not knowable from the ingredient list.
Where you’ll see it
In oil-in-water creams and lotions, where it does the ordinary work of holding the emulsion together — moisturisers, sunscreens, cleansing milks, hair conditioners. It is a common emulsifier, usually present at a low percentage. Those are illustrative categories, not a measured market prevalence, and label position is not a dose. The one thing worth checking on the label is the name itself. "Glyceryl Stearate SE" and plain "Glyceryl Stearate" are different INCI names with different legacy scores — 3 and 1 in Fulton's table — and only the first carries this page's Caution. If a label reads "Glyceryl Stearate" with no "SE", the number that applies is the plain grade's, and that ingredient has its own separate entry.
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, read off our verbatim transcription of Table I rather than via a list quoting it. A rabbit-ear assay: the ingredient diluted to roughly 10% in propylene glycol, applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, follicular keratosis measured with a micrometer, graded 0–5. It prints two separate rows for this ingredient — "Glyceryl stearate SE" at 3 and "Glyceryl stearate NSE" at 1 — which is the reason grade matters on this page. Fulton's own key files 0–1 as "not considered significant", 2–3 as "borderline" and 4–5 as "considered positive", and he called the survey "not at all definitive but simply designed to stimulate research." Not a measurement of a finished product, and not human data.
- 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) A genuinely independent rabbit-ear assay — a different laboratory, six years before Fulton, on the same 0–5 scale, and one that openly contradicts Fulton on other materials in print. It scored glyceryl stearate 2, tested at 50% in mineral oil. Cited as a real second measurement, with its limit stated: it records the material only as "Glyceryl Stearate," with no SE or NSE designation, so it corroborates that the ingredient is borderline in a rabbit ear but cannot adjudicate the difference between the two grades. Read from our transcription of its ingredient table (its oils table is printed rotated and is lost to OCR).
- Cosmetic Ingredient Review. "Amended Safety Assessment of Monoglyceryl Monoesters as Used in Cosmetics." Tentative Amended Report for Public Comment, released 2 October 2015 An industry-funded but independently paneled toxicological review. Cited here for two narrow, stable facts only: its ingredient table defines Glyceryl Stearate SE as "a self-emulsifying grade of glyceryl stearate that contains some sodium and/or potassium stearate" and gives its function as a surfactant/emulsifying agent, and it reports roughly 1,400 formulations using the SE grade. It is a public-comment DRAFT, not a final report, and it is flagged as such on its cover page; it summarises the settled 1982 CIR Final Report, which concluded both grades are safe for topical use. It is not comedogenicity evidence — it assesses safety, and its review of this ingredient does not use the words comedogenic, comedone, acne or follicle at all.
- Draelos ZD, DiNardo JC. "A re-evaluation of the comedogenicity concept." J Am Acad Dermatol 54:507–512 (2006) A Current Issues and Opinion piece in JAAD that tested finished products on human upper backs and found products testing non-comedogenic despite containing ingredients the rabbit assay had scored as comedogenic. Cited against this rating as much as for it: it is why the confidence here stays Low. It is evidence that a single ingredient's rabbit-ear score does not transfer to the formula it ends up in; it is not a head-to-head validation of the rabbit ear against human skin.
- "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 literature from 1972 to 2025. Finds that no standardised comedogenicity test exists and that the "non-comedogenic" label is unregulated. 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 that sits under every legacy score on this site.
Others in the same family
Emulsifiers 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 emulsifiers as a family ›
Last reviewed 2026-06-24 · How we decide