Acetylated Lanolin

Nearly every pore-clogging checker rates acetylated lanolin a 4 and tells you to avoid it. On his 1989 table the man who produced that number scored this ingredient 0, gave the 4 to a differently named molecule, and wrote down which additive he blamed. The lists dropped a word. But the same author's own 1984 table, which we have now read, prints 4 against this plain ester and has no separate alcohol row at all. Two readings, one investigator, five years apart, flatly at odds. We hold Caution because we will not pick the convenient one.

What it is

Lanolin, acetylated. The Cosmetic Ingredient Review describes the process plainly: lanolin is reacted with acetic anhydride, and ester bonds form between the acetate groups and the hydroxyl groups of the lanolin's own esters. The starting material is the whole wax — the intact mixture scoured from sheep's wool — and the product is that whole wax with its free hydroxyls capped. Capping them is the point. It makes the material less sticky, less prone to oxidation, and far more soluble in the oil phase of a formula, which is why a formulator reaches for it rather than for lanolin itself: it gives lanolin's occlusive cling without lanolin's tack. Hold on to the phrase "the whole wax," because the entire argument on this page turns on it. There is a second, different ingredient with a very similar name. ACETYLATED LANOLIN ALCOHOL is not made from the whole wax. Lanolin is first fractionated — split into its alcohol and fatty-acid components — and only the alcohol fraction is then acetylated. Different starting material, different product, different molecule. They carry different CAS numbers (61788-48-5 for acetylated lanolin; 61788-49-6 for acetylated lanolin alcohol) and they appear as two separate ingredients in the CIR's own assessments. On a label they are two separate declarations.

Why we rate it Caution

We rate it Caution at Low confidence, and that is not the rating you would predict from what follows. On Fulton's 1989 table the famous 4 is not this molecule's. We are about to prove that from the primary source, and it is the finding this page exists for. What it does not do is settle the question, because the same author's 1984 table — read in full since, and set out further down — scores this exact ester 4. The correction is real and the conflict is real, and a page that gave you only the first would be doing to you what the lists do. The number you have seen. Search this ingredient and you will be told it scores 4 out of 5 and that anyone acne-prone should avoid it. That number, like most of the comedogenic scores in circulation, descends from James Fulton — though from which of his two rabbit-ear tables the lists never say, and it matters here more than anywhere, because the two do not agree. The usual attribution is the 1989 survey in the Journal of the Society of Cosmetic Chemists. So we did the only thing that settles these questions: we read it. Then we read the other one. What Fulton's 1989 table actually prints. His table contains two separate rows for these materials. Our transcription records section headings for two blocks of that paper only, and this is not one of them, so we give the row rather than a heading we cannot produce. "Acetylated lanolin — 0, 0." Zero for comedogenicity, zero for irritancy. And "Acetylated lanolin alcohol — 4, 2." By Fulton's own published key, "a minimal grade of 0 to 1 is not considered significant," while "a grade of 4 to 5 is uniformally reproduceable and considered positive." On that table, the 4 belongs to the molecule on the other row. Whether the 4 that follows this ingredient around the internet was copied from there, or from the single undivided row his 1984 paper prints under this ingredient's own name, is not something the lists record and not something we can trace. What the 1989 table settles is what the 1989 table says. He then does something almost nobody quoting him has noticed. He explains it. In the body of the paper he writes that the acetylated lanolin alcohols "are both comedogenic and irritating, not because of the acetylated lanolin but because of the cetyl acetate additive." The caption to his Figure 1 says it again: "The key ingredient is acetylated lanolin alcohol — cetyl acetate — is not only comedogenic, but it is also an irritant." And his table carries a third row we had to go looking for: "Cetyl acetate — 4, 2." The same two numbers as the row above. The author of the score is telling you, in print, that the score is not the plain ester's, and naming what he thinks is responsible. Then his conclusion lists the major offenders — "isopropyl myristate, acetylated lanolin alcohol, and lauric acid derivatives." Alcohol. Not this ingredient. Four times in one paper, he distinguishes them; the lists that quote him distinguish them zero times. Now the limit of what that proves, because there is a trap here and we walked into it. If Fulton's "acetylated lanolin alcohol" row was a cetyl-acetate-containing commercial blend — which is what his own prose implies — then that row is NOT a clean score for the isolated alcohol either. We cannot have it both ways, and the first draft of this page did: it used the same row to argue that the 4 belongs to a blend, and then quoted it as the pure alcohol's verified score. Those two statements cannot both be true. Fulton never reports his supplier, his trade name, his blend ratio, or a certificate of analysis, so the composition of the material behind that row is not recoverable. What is established is narrower: a material Fulton LABELLED "acetylated lanolin alcohol" scored 4, and he attributed that result to a cetyl acetate additive. What the isolated alcohol does on its own is not something this paper settles. A manufacturer sells such a blend today, which corroborates that the material exists — and no more than that. Lubrizol's technical page describes Acetulan as "a 100% active, cetyl acetate and acetylated lanolin alcohol." That tells you what Lubrizol sells NOW. It does not tell you that Fulton used Lubrizol's product, that the 1989 sample had this ratio, or that every commercial acetylated lanolin alcohol on earth contains cetyl acetate. We previously wrote that "the supplier still confirms it, thirty-seven years later," which quietly turned a current product spec into a certificate of analysis for a 1989 rabbit assay. It is not one. There is a second reading of the table, and it is independent. Morris and Kwan, 1983, six years before Fulton and in a different laboratory: we hold their rows and their row reads "Acetylated Lanolin Alcohol — 4–5". They have NO row for the plain ester at all. So the two tables that print a row under the ALCOHOL name agree on where a high number sits. What they cannot do is settle this page, because the third table we have read — Fulton's own, from 1984 — prints a 4 under this ingredient's name and prints no alcohol row anywhere. Two more papers get cited for this — Lanzet 1986 and Kligman and Mills 1972 — and you will find both quoted against the alcohol. WE HAVE NOT READ EITHER OF THEM, so we are not going to hand you their numbers, on this page of all pages. What we can tell you is what our own reference file records about them, which is why they would not settle it anyway: Lanzet is collated MANUFACTURER data, not an assay, and it runs on a 0–3 scale rather than Fulton's 0–5; Kligman and Mills used a rabbit ear CANAL method that KLIGMAN HIMSELF later disowned, and it is 0–3 as well. Two numbers on the wrong scale from documents we have not opened would add the appearance of corroboration and none of the substance. And one caveat covering all of it, because it cuts our way and we would rather say it than have it said to us: nobody in this literature discloses whether their "acetylated lanolin alcohol" was neat or an Acetulan-type blend. Morris and Kwan do not. Fulton does not. So read the whole pattern as a consistent fact about how the material is NAMED, not as independent confirmation of what the isolated molecule does.

What the evidence doesn’t tell you

Here is the evidence that cuts against us, and we would rather hand it to you than have you find it. Fulton's own EARLIER paper — Fulton, Pay and Fulton, 1984, in the Journal of the American Academy of Dermatology — says in its abstract: "Lanolins continue to be a problem, especially derivatives such as acetylated or ethoxylated lanolins." For a long time this page could only cite that abstract, because the table was paywalled and we do not tell you what a document says until we have seen it. A print copy was obtained on 18 July 2026, and the table is now READ in full. It prints "Acetylated lanolin — 4" — for the plain ester, and note this: in 1984 there is NO separate "acetylated lanolin alcohol" row at all. The split into two molecules that the 1989 correction turns on is a refinement Fulton made LATER. So in 1984 he scored a single row, "acetylated lanolin," a 4; in 1989 he scored "acetylated lanolin" 0 and put the 4 on "acetylated lanolin alcohol." So Fulton's own two papers conflict on the plain ester: 4 in 1984, 0 in 1989. The 1989 correction — that the famous 4 belongs to the alcohol — is still true of the 1989 table, and it is the finding this page exists for. But it is not the whole record, because the same author scored the plain ester 4 five years earlier, before he separated the molecules. We now carry both readings, because we have read both; the legacy figure on this page stays Fulton's 1989 zero, with the conflicting 1984 four recorded beside it. So the honest statement of the record is this. Two papers have now been read for this exact material. Fulton 1989 prints 0; Fulton 1984 prints 4. They conflict, and the conflict is what the rating rests on. And that is why the rating is Caution, which is a reversal we owe you an account of. For one day this page rated the ingredient CLEAR. The argument was that our own rules forbid carrying a score we have not read, so rating Caution on the strength of the unread 1984 four would be the exact sin we accuse every list of committing. That argument is right — about the SCORE. We do not carry the 4, and the legacy score on this page is still Fulton's 0. But it smuggled the rule about scores into a judgement about ratings, and those are different things. Read what Clear means here: NO COMEDOGENIC CONCERN ON RECORD. A concern is on record. It is in a primary paper by the same author — an abstract we had read and a table we could not then open, and the table has since been read and prints 4. That is not an absence, and treating it as one is how a gap becomes a clean bill. It is an unresolved conflict, and Caution is the word this site uses for exactly that — the same call we make on sodium lauryl sulfate, where two assays flatly disagree. And not Clogging either, which is the other half of the account and the easier half to skip. To rate it Clogging we would have to promote one of two contradicting readings by the same author because it is the alarming one, and print as our own verdict the sentence we retracted when the lists printed it. The record is a 4 that is positive under the 1984 key and a 0 that is not significant under the 1989 one, from one investigator, five years apart, with no correction, no retraction and no same-batch replication standing between them. Nothing in that entitles us to pick. Caution here is not splitting the difference. It is the accurate report that two readings have not been reconciled, and that we are not the ones who can reconcile them. There is a less flattering reason too, and it belongs on the page. "Acetylated lanolin scores 0, not 4" is the most attention-getting sentence we have. It is the tidy story. On the day we wrote it we also wrote — on this same page — that "the only assay that has ever tested this material found nothing", which was false, and which pointed the same way. When every error you make leans in the direction that makes your argument better, the lean is the thing to distrust, not the errors. ONE DOCUMENT DECIDED THIS, and it is now read. The 1984 table prints "Acetylated lanolin — 4" for the exact material, so this is a genuine conflict between two papers by the same author, and the rating stays at Caution — not the reversal to Clear that a missing or low 1984 row would have triggered. Either way the correction is untouched: on the 1989 table the famous 4 belongs to a different molecule, and Fulton says so himself. We do not need the rating to be Clear for that to be true, and a page that needed it would be a page arguing backwards from its conclusion. What can be said for the 1989 paper over the 1984 one is weaker than "supersedes," which is the word we used and should not have: Fulton never issued a correction, a retraction, or a same-batch replication, and the two studies may have used different suppliers, grades, blends or thresholds. What is true is that the 1984 numbers run hotter across the board (it scores anhydrous lanolin 2 where 1989 scores it 0–1; cetyl alcohol 3 where 1989 scores it 2), that its grade key sets the positive threshold lower (in 1984, 3 and above is "positive"; in 1989 that band is 4–5), and that 1989 is the same author's later and more granular work — the one where he separates the two molecules at all. Those are reasons to weight 1989. They are not a proof, and we are not going to dress them up as one. The outstanding job this used to name — get the 1984 print copy — is done, and the rating's hole is now a conflict we can show you in full rather than a gap. Everything here rests on a rabbit's ear. Three rabbits, roughly 10% ingredient in propylene glycol, applied to the inner ear five days a week for two weeks, follicles then scored for keratosis. It is not a human face, not a finished formula, and not a realistic concentration. Draelos and DiNardo's 2006 re-evaluation in the Journal of the American Academy of Dermatology tested finished products on small human panels and concluded that isolated rabbit-ear ingredient scores are a poor guide to what a product does on human skin — it was not a human re-test of this material, and we should not imply it was. The 2025 JAAD Reviews survey of the field found no standardised comedogenicity test exists at all. Those objections apply to a 0 exactly as much as to a 4. The one assay we have READ found nothing here. That is not the same as the assay being any good. We have found no human comedone study of plain acetylated lanolin. The CIR's 2024 Final Amended Report contains no comedogenicity result for this exact material either — though it is not silent on the subject, and we previously said it was. It has a Comedogenicity section. What that section reports is that hydroxylated lanolin at 6% in cottonseed oil was non-comedogenic in a rabbit study, and that a finished product containing lanolin at an unreported concentration was non-comedogenic in a 15-subject randomised trial. Neither is this ester. A general discussion of the family is not an absence of discussion, and the difference matters on a page built on exactly that distinction. Finally, an accusation we are NOT going to make until we can back it. We had written that the 2025 review "Comedogenicity in cosmeceuticals" prints a table row giving acetylated lanolin 4–5, and that the conflation has therefore been laundered into the peer-reviewed literature. We have not been able to open that table. Secondary summaries agree that the row reads that way, and if it does it is a significant finding — but accusing named authors in a dermatology journal of reproducing an error, on the strength of a search result we could not check, is not something we are prepared to do. It stays on our list to verify. It does not stay in our argument.

Where you’ll see it

Emollient-heavy leave-on products: lipsticks and lip balms, cream blushers and foundations, hand and body creams, hair conditioners and pomades. It is used where lanolin's occlusive cling is wanted without lanolin's tack. Those are illustrative categories, not a measured prevalence — we have not audited the market — and we are not going to tell you where it sits on a label, because position is not a dose and we do not know. The practical instruction is short. Read the label for the word ALCOHOL. "Acetylated Lanolin" is the ingredient on this page, and the two Fulton tables we have read disagree about it — 0 in 1989, 4 in 1984, each under its own key. "Acetylated Lanolin Alcohol" is a DIFFERENT ingredient, and the two tables that carry a row under that name put a high number on it: Fulton 1989 a 4, Morris and Kwan 4–5. We rate it Clogging and it has its own page. What none of those papers establishes is whether the alcohol is comedogenic BY ITSELF, because Fulton blames a cetyl acetate additive and none of the papers we have read discloses what was actually in the jar. If you see "Cetyl Acetate" and "Acetylated Lanolin Alcohol" together on a label, that is an Acetulan-type blend: the kind of material Fulton was describing. Cetyl acetate has its own row at 4. We are not going to tell you that "both components score 4", which the first draft of this page did, because Fulton's own explanation is that one component is carrying the other. One word on the label decides which of these three things you are holding.

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.

1. Fulton JE. "Comedogenicity and irritancy of commonly used ingredients in skin care products." J Soc Cosmet Chem 40:321–333 (1989) The primary source, and the origin of essentially every comedogenic number in circulation, including this one. Read in full off the journal scan rather than via a list that quotes it. FOUR separate things in this paper establish the point, which is why we are willing to stand against the consensus: Table I prints "Acetylated lanolin 0 0" and, three rows down, "Acetylated lanolin alcohol 4 2"; the same table prints "Cetyl acetate 4 2"; the body text states the alcohols are comedogenic "not because of the acetylated lanolin but because of the cetyl acetate additive"; and the conclusion names acetylated lanolin ALCOHOL among the major offenders. Method: ~10% in propylene glycol, inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, follicular keratosis measured under a micrometer.
2. Fulton JE, Pay SR, Fulton JE III. "Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear." J Am Acad Dermatol 10:96–105 (1984) The evidence AGAINST our rating, cited here deliberately. The same author, five years earlier, and now READ IN FULL (print copy obtained 18 July 2026). Its abstract says "Lanolins continue to be a problem, especially derivatives such as acetylated or ethoxylated lanolins," and its Table I prints "Acetylated lanolin — 4" — with NO separate "acetylated lanolin alcohol" row, so the split into two molecules is a refinement Fulton made only in 1989. This confirms the conflict: he scored the plain ester 4 in 1984 and 0 in 1989. Its numbers run hotter than the 1989 paper's throughout (anhydrous lanolin 2 versus 0–1; cetyl alcohol 3 versus 2), and its grade key sets "positive" at 3 and above rather than 1989's 4–5. It does not overturn the 1989 correction (on that table the 4 is the alcohol's), but it is a genuine same-author conflict, which is why the rating is Caution.
3. Lubrizol — Acetulan™ lanolin derivative, technical product page Manufacturer documentation, and independent corroboration of Fulton's 1989 explanation from a completely different direction. Lubrizol describes Acetulan as "a 100% active, cetyl acetate and acetylated lanolin alcohol" — the comedogenic material is sold, today, as the two-component blend Fulton blamed. Not a comedogenicity study; a statement of what the tested substance actually is.
4. Cosmetic Ingredient Review. "Amended Safety Assessment of Lanolin and Lanolin-Derived Ingredients as Used in Cosmetics" — FINAL AMENDED REPORT, released 21 November 2024 Cited for exactly one thing: it establishes that acetylated lanolin and acetylated lanolin alcohol are separate ingredients, with separate CAS numbers and different manufacturing routes (whole wax versus the isolated alcohol fraction). A safety assessment is not a comedogenicity study and we do not use it as one. TWO CORRECTIONS TO OUR OWN CITATION, and they are why this note is long. We had the right document NAME attached to the wrong FILE. The link pointed at `Lanolin.pdf`, whose own first page reads "Status: Re-Review for Panel Consideration. Release Date: May 19, 2023" — a packet circulated for a panel meeting, not a settled assessment. The real Final Amended Report was released 21 November 2024, and is what we link now, verified by reading its cover page. That is the THIRD comment-stage CIR document this site has cited as though it were final: the brown-algae draft stamped "Do Not Cite or Quote", the shea "Amended Tentative Report for Public Comment", and this. Three is not bad luck. CIR publishes draft, tentative, amended-tentative, re-review and final versions at near-identical URLs, and a search engine hands you whichever it likes. The rule now: read the status line on page one before citing. And we said it "contains no comedogenicity data at all." It has a Comedogenicity section — it is simply not about this ester. What it reports is that hydroxylated lanolin at 6% in cottonseed oil was non-comedogenic in a rabbit study, and that a finished product containing lanolin at an unreported concentration was non-comedogenic in a 15-subject randomised trial. No result for acetylated lanolin. Absence of a number is not absence of discussion, and on a page whose whole argument is that distinction, we blurred it.
5. 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) An independent primary assay on the same 0–5 scale, six years BEFORE Fulton 1989 — not a republisher of him. Cited here for what it does NOT contain: it scores a material named "Acetylated Lanolin Alcohol" 4–5, and has no row for the plain ester at all. Every legacy paper reporting a high lanolin-derivative score names the ALCOHOL, and that consistency is real. But we previously called it "unanimity" and made it the second leg of the rating, which is more weight than it bears: Morris and Kwan do not disclose their supplier or whether their sample was a cetyl-acetate blend, so this confirms a pattern in the NAMING, not four independent measurements of one molecule.
6. Draelos ZD, DiNardo JC. "A re-evaluation of the comedogenicity concept." J Am Acad Dermatol 54:507–512 (2006) The paper that undermines the rabbit-ear assay in general, cited here because it cuts against our reassuring 0 exactly as hard as it cuts against anyone's alarming 4. It tested FINISHED PRODUCTS on small human panels and concluded that isolated rabbit-ear ingredient scores are a poor guide to what a product does on a human. It was NOT a human re-test of acetylated lanolin, and we previously implied a generality it does not have. We could not read its methods (paywalled), so we make no claim about which material it used as a positive control.

Others in the same family

Lanolin & derivatives 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 lanolin & derivatives as a family ›

• Acetylated Lanolin Alcohol Clogging Low
• Isopropyl Lanolate Caution Low
• Lanolin Caution Low
• PEG-16 Lanolin Clogging Low

Last reviewed 2026-08-20 · How we decide

‹ Check a full ingredient list