Porecelain

Flawless skin starts with the fine print.

Centella Asiatica Extract

Centella asiatica extract rates Clear, but the rating is a judgement rather than a reading: we identified no comedogenicity assay of it in any of the numeric papers we hold, and the 0-to-1 that ingredient checkers print has no primary assay behind it that we could trace. What sits in place of an assay is in vitro work on an isolated triterpene and a pooled treatment review we set aside as low-confidence, neither of which measures comedone formation. It is also an extract, not a single molecule, which makes even the question underspecified.

Clear Low confidence No legacy score. It does not appear in the assay corpus we searched.

No assay we can find, and no comedogenic concern on record.

What it is

Centella asiatica is a low-growing herb, known in traditional medicine as gotu kola, and "Centella Asiatica Extract" on a label is a solvent extract of the plant rather than a defined compound. It is marketed in cosmetics under the shorthand "cica." Its activity is usually attributed to four pentacyclic triterpenes: two aglycones, asiatic acid and madecassic acid, and their sugar-bearing storage forms, asiaticoside and madecassoside. The relative amounts of these move with the plant part used, the growing conditions and the extraction solvent, so two materials both labelled Centella Asiatica Extract are not necessarily the same thing. The Cosmetic Ingredient Review's 2015 assessment lists centella-derived ingredients as functioning primarily as skin-conditioning agents. On a label the material appears as Centella Asiatica Extract, and its close relatives — Centella Asiatica Leaf Extract, Leaf Water, Root Extract, Callus Culture and the various cell-culture extracts — are separate INCI names, nine of them in the CIR review, and are not interchangeable. Because it is an extract standardised on a mixture, the usual comedogenicity question ("what score does this material get") is harder to ask cleanly than it is for, say, a single fatty ester. A characterised commercial lot could certainly be assayed; the result would belong to that lot, and would not carry over to the next one.

Why we rate it Clear

We rate centella asiatica extract Clear at Low confidence. Clear here is an editorial risk classification, not a measured pass: it records that we found no adverse comedogenic signal in the documents we read, and the Low records that a direct comedogenicity measurement is missing entirely. Start with what is absent, because it is most of the story. We identified no comedogenicity assay of centella asiatica — extract or isolated triterpene — in the sources and searches reviewed for this page. Fulton's 1989 rabbit-ear table, the source of most of the comedogenic numbers now in circulation, has no centella, Centella asiatica or gotu kola row; we read its 220 rows off a 400dpi render. This absence is worth one extra sentence, because Fulton's table is not all lipids: its "Vitamins and herbs" section carries two botanical extracts he did put on a rabbit's ear — black walnut extract at 0 and chamomile extract at 0, both on his 0-5 scale — so the gap where centella would sit is not explained by plant extracts being out of scope. Fulton, Pay and Fulton's separate 1984 rabbit-ear paper, on its own 0-5 scale (1-2 not significant, 3 or above positive), prints no centella row either. Morris and Kwan's 1983 assay, an independent laboratory on the same 0-5 scale, tested thirty-two materials, all of them lanolins, vegetable oils, esters or surfactants; centella is not among them. Nguyen, Dang and Maibach's 2007 rabbit-ear study, on a 0-4 scale, names its fourteen test materials in its abstract and centella is not one of them. acne.org, which catalogues eleven published comedogenicity studies between 1972 and 2009, gives it no entry we could find. Our own index of the legacy corpus records no score for centella asiatica extract from any document in it — a statement about that corpus, not a claim about the whole literature. That is why our legacy score field is blank rather than zero. Consumer checkers do print a low number — CosDNA lists Centella Asiatica Extract at 1 on its 0-5 "acne" scale, and some auto-generated ingredient pages print 0 — and we could trace neither to a primary assay. We are not going to say who entered the number or why, because we do not know; the honest statement is narrower. There is no measurement behind it that we identified, and a low number sitting in the same column as coconut butter's measured 4 invites a reader to treat an untested ingredient as a tested and cleared one. Untested is not the same as safe. What centella has in place of an assay is laboratory work that explains why it is used in blemish products, and that work is not a comedogenicity measurement, so we will name exactly what it is. Shen and colleagues (2019) showed that isolated madecassoside reduced pro-inflammatory signalling (interleukin-1β, TLR2, NF-κB) in cultured human immune cells stimulated with Cutibacterium acnes, the bacterium implicated in inflammatory acne, and raised markers of skin hydration in cultured keratinocytes. That work was in vitro, on an isolated triterpene rather than the extract, and it measured inflammatory signalling and hydration — not whether anything plugged a follicle. Cell culture is not evidence from people, and it tells us nothing about whether the extract is comedogenic. Clear rests on two things, and neither is a comedone count: an absence we looked for and did not fill, and no adverse comedogenic signal in the documents we read. That is also why the confidence is Low.

What the evidence doesn’t tell you

This rating is built almost entirely on absence of evidence, which is a weaker thing than evidence of absence. We identified no rabbit-ear assay of centella, no human comedone-induction study, no cyanoacrylate follicular biopsy — in either direction. An absence of findings and an absence of looking produce the same silence, and here it appears to be the second. An audit can establish that no assay turned up in the papers we hold and the searches we ran; it cannot establish that none was ever run anywhere. Clear is the least-wrong call available, not a clean bill of health, and if the assay were run tomorrow we would have no standing to be surprised by the result whichever way it fell. The material makes even that weaker than usual. "Centella Asiatica Extract" is not one substance: it is a mixture whose triterpene profile shifts with plant part, growing conditions, solvent and degree of standardisation. A characterised commercial lot could be assayed, but the result would belong to that lot: it would not carry over to a material from another plant part, another growing season or another solvent. So the honest position is that centella has not been assayed in anything we hold, and that a single result would not settle the question for the ingredient as labelled. The literature a reader will meet is about treating acne rather than causing it, and it measured the wrong endpoint for this exact question. Trials of centella in acne are treatment-efficacy work — they count lesions under treatment — and "comedogenic" refers to comedone formation, which those studies did not set out to induce or count. They also tested finished creams, gels and oral supplements, and isolated triterpenes, rather than the cosmetic extract on its own, and a result about a formula or a purified fraction is not a result about the labelled ingredient. We looked specifically for the pooled claim a reader is likeliest to meet — a 2024 "systematic review and meta-analysis" of centella in acne — and excluded it as low-confidence evidence: it appears in a low-impact journal, was acknowledged as supported by the authors' own clinic, pooled topical and oral interventions together, and had treatment of acne rather than induction of comedones as its endpoint. We carry none of its figures, in either direction, and we flag it here only because its confident, specific numbers are the kind a reader will find first. Safety is not comedogenicity either. The Cosmetic Ingredient Review concluded that centella-derived ingredients are safe as used "when formulated to be non-sensitizing," a phrasing that itself points at centella's documented history as a contact allergen. Contact allergy is a real consideration and a different endpoint: an ingredient can provoke an allergic reaction in some people and have nothing to do with plugging pores, and the reverse. A safety conclusion addresses irritation, sensitisation and toxicity; we identified no comedogenicity data within it, and its silence on pores is not evidence that the wider literature is silent. Finally, we have no dose-response information of any kind — no comedogenic number attaches to any concentration — and where centella sits on an ingredient list tells a reader nothing. Beyond this ingredient, a 2025 review of the field reports that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label.

Where you’ll see it

On a label it appears as Centella Asiatica Extract, in products sold for calming, soothing or "barrier" support and in the moisturisers, serums, toners, masks and spot treatments marketed under the "cica" shorthand. The Cosmetic Ingredient Review's 2015 assessment reports centella-derived ingredients in leave-on and rinse-off cosmetics as skin-conditioning agents, with Centella Asiatica Extract used at up to 0.5% in face and neck products in the survey data it cites — a low-percentage active, not a base or an emollient. That figure is from a 2015 use survey and should be read as dated rather than as a current market description. Its relatives are worth keeping separate from it, because the extract identity is the whole complication here. Centella Asiatica Leaf Extract, Leaf Water, Root Extract, Callus Culture, Meristem Cell Culture and the cell-culture extracts are distinct INCI names — nine centella-derived ingredients in the CIR review — and nothing on this page transfers cleanly between them. Where in a list centella appears is not a comedogenicity signal, here or anywhere, and there is no measured number to read off it in any case.

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 rabbit-ear survey most online comedogenic numbers descend from. Method: 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 whose own key reads 0-1 "not considered significant," 2-3 "borderline," 4-5 "considered positive." Read here off a 400dpi render of the journal scan rather than through a list quoting it. Cited purely for an absence: its 220 rows contain no centella, Centella asiatica or gotu kola entry. Its "Vitamins and herbs" section does carry two botanical extracts — black walnut extract (0) and chamomile extract (0) on the same 0-5 scale — so the absence is not a section that went untested. Fulton called the survey "not at all definitive." It supports no rating of centella in either direction.
  2. Fulton JE Jr, Pay SR, Fulton JE 3rd. "Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear." J Am Acad Dermatol 10(1):96–105 (1984) An earlier, separate rabbit-ear study from the same lead author, on its own 0-5 scale whose key is not the 1989 key: 1-2 is read as not significant and 3 or above as positive, so its numbers cannot be carried across to 1989 numbers without each paper's own key. Cited for a verified absence: it prints no centella row, and so adds no score in either direction.
  3. 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 laboratory's rabbit ear-canal assay on the same 0-5 scale, three rabbits, graded microscopically. It predates Fulton 1989 and contradicts it in print on several materials, which is why it is not a republisher of him. Its thirty-two test materials are lanolins, vegetable oils, esters and surfactants. Cited for an absence: centella is not among them.
  4. Nguyen SH, Dang TP, Maibach HI. "Comedogenicity in rabbit: some cosmetic ingredients/vehicles." Cutan Ocul Toxicol 26(4):287–292 (2007) A later rabbit ear-canal study on a 0-4 scale — a third scale, easy to misread as Fulton's. Its abstract names all fourteen test materials (esters, fatty alcohols, hydrocarbons, one butter and one surfactant). Cited for an absence: centella is not one of them.
  5. acne.org — "What is comedogenicity, and what ingredients are comedogenic? The full story" A republisher of the legacy assays, but a thorough one: it describes eleven published comedogenicity studies from 1972 to 2009 with their methods, and combines them under its own multi-study rule rather than quoting one table. Not an independent measurement of anything. Cited as an index of the literature rather than as evidence — we found no centella entry in it, which is a statement about this document, not about every document.
  6. Cosmetic Ingredient Review Expert Panel (Johnson W, Bergfeld WF, Belsito DV, et al.). "Safety Assessment of Centella asiatica-Derived Ingredients as Used in Cosmetics." Final Report, June 2015; republished Int J Toxicol 42(1 Suppl) (2023) The industry expert-panel SAFETY dossier, in its final published state. Cited for identity, use and tolerance only: nine centella-derived ingredients assessed as skin-conditioning agents; Centella Asiatica Extract used at up to 0.5% in face and neck products in the survey it cites; overall conclusion "safe as used" conditioned on being "formulated to be non-sensitizing," which reflects centella's documented history as a contact allergen. We identified no comedogenicity data in it. A safety conclusion is not evidence of noncomedogenicity, its use table is not a current market survey, and its silence on pores is not evidence that the wider literature is silent. Cited from the CIR final report and its 2023 journal republication; we have not independently read every page and do not claim it is an exhaustive index of every experiment.
  7. Shen X, Guo M, Yu H, Liu D, Lu Z, Lu Y. "Propionibacterium acnes related anti-inflammation and skin hydration activities of madecassoside, a pentacyclic triterpene saponin from Centella asiatica." Biosci Biotechnol Biochem 83(3):561–568 (2019) In vitro laboratory work on ISOLATED madecassoside — not centella extract, not in a pore, not in a person — showing it lowers pro-inflammatory signalling (IL-1β, TLR2, NF-κB) in cultured human cells stimulated with Cutibacterium acnes, and raises hydration markers in cultured keratinocytes and fibroblasts. Cited as context that explains why centella appears in blemish products, explicitly not as a comedogenicity result: inflammatory signalling and hydration are different endpoints from follicular plugging. Disclosed affiliation: several authors are with the technology centre of Shanghai Inoherb Co. Ltd, a cosmetics company.
  8. Utami AT, Muzaahim A, Harrats AH, Imroon MA. "Systematic Review and Meta-Analysis: Efficacy of Centella Asiatica in Treating Acne Vulgaris." Biomed J Sci Tech Res 58(2):50034–50037 (2024) A pooled analysis of centella in the treatment of acne, carried here as excluded low-confidence evidence rather than as support for anything. Cited because it is the pooled claim a reader is likeliest to meet, and to say plainly why we did not use it: it is a TREATMENT-efficacy analysis (lesion counts), not a comedogenicity measurement; it pooled topical creams and gels with oral supplements; it appears in a low-impact journal (stated impact factor 0.548) whose acknowledgements thank the authors' own clinic as sponsor; and its underlying study list could not be independently verified. We carry none of its figures.
  9. "Comedogenicity in cosmeceuticals: a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the comedogenicity field from 1972 onward. It is a synthesis of the legacy literature, not a new measurement, and independent of Fulton only in authorship. Cited for one 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.
  10. Consumer comedogenic checkers and ingredient databases (CosDNA and similar) Aggregators that publish a 0-5 "acne" number per ingredient with no disclosed method, provenance or citation. Centella Asiatica Extract is listed at 1 on CosDNA's acne scale; some auto-generated ingredient pages print 0. Cited as the artefact being corrected, not as a measurement: we traced no primary assay behind either number and make no claim about where it came from or who entered it. It is not carried as our legacy value.

Others in the same family

Botanical extracts 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 botanical extracts as a family ›

Last reviewed 2026-08-12 · How we decide

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