Stearic Acid
Stearic acid (INCI name Stearic Acid) is rated 2 to 3 on our list, a range whose top puts it in the moderate band, and the number is traced: Fulton 1989 graded it 2 to 3, varying with the supplier.
Like every rating here, it is for the raw ingredient tested alone, and a label does not print how much of it a product holds.
Is stearic acid comedogenic?
Stearic Acid is rated 2–3 on the comedogenic scale: our list gives it a range from 2 to 3, and the band follows the 3 at the top.
A waxy fatty acid used to thicken lotions, stabilize formulas, and act as a mild cleanser.
- Comedogenic rating
- 2–3 out of 5 (a range on our list)
- Band
- Moderate: Borderline plugging in the rabbit-ear test. Worth a look in a leave-on product.
- Where the number comes from
- Traced to Fulton 1989. The section on who rated it prints each grade.
- Composition
- Fatty Acid(s) & Derivatives
- Also written as
- No common variants recorded
What a 2–3 means in practice
Three is the middle of the scale. Fulton 1989 counted 2 to 3 as borderline in the rabbit-ear test: some plugging of the follicles, short of a clear positive. Whether it matters depends on how high it sits on the label and whether the product stays on your skin.
Two things change what this number is worth. Ingredients are listed in descending order of concentration, so stearic acid near the top of a label matters far more than stearic acid at the bottom. And the rating describes the raw ingredient on its own. A 2006 review in the Journal of the American Academy of Dermatology found that a rating for a single ingredient does not reliably predict how a finished formula behaves on human skin. The full story of the scale is here.
Who rated it
Our list gives stearic acid 2–3. These are the figures the published rabbit-ear studies we have read give it, as printed in each paper's table.
| Paper | Grade | Tested as |
|---|---|---|
| Fulton 1989 | Grade 2 to 3, varying with the supplier | Tested as Stearic acid |
Our list's figure is within what these papers report.
Similar names, rated separately
These share a source with stearic acid or carry it in their name, and each has its own rating on our list. The 2–3 on this page does not carry over to them, so check the exact name on the label.
Others in the same family
Where stearic acid comes up on this site
Fungal acne
Stearic Acid matches rule 1, fatty acid, C12 to C24 , on the fungal acne checker. Stearic acid, C18. The rule comes from lab studies of what Malassezia yeast can feed on, and it is not a verdict on any product.
What safety reviewers say
The rating above is about pore plugging in a rabbit-ear test. Whether stearic acid is safe to use in cosmetics is a separate question. Below is the conclusion of the Cosmetic Ingredient Review (CIR), a US expert panel, and what the EU ingredient database, CosIng, lists for it. We quote CIR's conclusion as written, read on 31 October 2026.
- Cosmetic Ingredient Review (US)
- In a 2019 review of 102 fatty acids and fatty acid salts, stearic acid among them, the panel concluded they are “safe in the present practices of use and concentration described in the safety assessment when formulated to be non-irritating and non-sensitizing, which may be based on a QRA”. A QRA is a quantitative risk assessment. Safety Assessment of Fatty Acids & Fatty Acid Salts as Used in Cosmetics, 2019 (opens in a new tab)
- What it does in a product (EU CosIng)
- Listed as STEARIC ACID: cleansing, surfactant (emulsifying), emulsion stabilising, fragrance, refatting, surfactant (cleansing). CosIng entry (opens in a new tab)
- EU restrictions
- None. CosIng shows no entry for it in the annexes of the EU Cosmetics Regulation.
What we make of this. CIR's conclusion does not grade pore plugging, so on its own it neither confirms nor contradicts the 2–3 on our list. A safety review looks at things like irritation, allergy and toxicity at the amounts products use, and the rating is only about pores, so read them side by side.
Common questions
- Is stearic acid comedogenic?
- Stearic Acid is rated 2–3 on the comedogenic scale: our list gives it a range from 2 to 3, and the band follows the 3 at the top.
- Is stearic acid non comedogenic?
- No. Stearic Acid is rated 2–3 on the comedogenic scale, which is the moderate band. That is a published rating for the ingredient rather than a verdict on any product containing it.
- What is stearic acid's comedogenic rating?
- 2–3 out of 5 on our list. It is classed as Fatty Acid(s) & Derivatives.
Sources we checked this rating against
- Kligman AM, Kwong T. “An improved rabbit ear model for assessing comedogenic substances.” British Journal of Dermatology, June 1979;100(6):699–702. (opens in a new tab) The rabbit-ear assay behind published 0 to 5 comedogenicity grades.
- Fulton JE Jr. “Comedogenicity and irritancy of commonly used ingredients in skin care products.” Journal of the Society of Cosmetic Chemists, November/December 1989;40(6):321–333. (opens in a new tab) Rabbit ear. Each ingredient at 10 percent in propylene glycol unless stated, applied five days a week for two weeks, and graded 0 to 5 from the width of the follicles, measured by micrometer and under the microscope. The paper counts 0 to 1 as not significant, 2 to 3 as borderline and 4 to 5 as positive. Some grades depended on the supplier of the raw material, and some oils were also tested refined.
- Draelos ZD, DiNardo JC. “A re-evaluation of the comedogenicity concept.” Journal of the American Academy of Dermatology, March 2006;54(3):507–512. doi:10.1016/j.jaad.2005.11.1058 (opens in a new tab) Tested finished products on the backs of six people and concluded that “Finished products using comedogenic ingredients are not necessarily comedogenic.”