When an ingredient is not on the list
Paste a label into the checker and some of what you typed will come back with nothing against it. That is worth understanding, because it is the part people most often read the wrong way round.
Short answer: An ingredient missing from this site's list of 285 has no rating here, which is a different statement from a rating of 0. It may have been tested and not blocked pores, or nobody may have tested it, and the list alone cannot tell you which. Read the rest of the label, and ask a dermatologist about a specific ingredient.
This site publishes 285 ingredients that carry a comedogenic rating on its list; 123 of those ratings trace to the dermatology literature and the rest are marked unconfirmed. It is a list of things that have been rated, and most of what has been rated was rated because somebody suspected it of blocking pores. So an ingredient missing from it has no rating here, and that is a different statement from a rating of 0.
Absent could mean it was tested and did not block pores. It could mean nobody has tested it. From this list alone the two look identical, and this site will not guess which.
The ones people ask about most
- Vaseline also written as Petroleum jelly, Petrolatum
- No rating is published for it here. An occlusive, and the single most searched of these. What the studies say about Vaseline and pores.
- Squalane
- No rating is published for it here. Not the same substance as squalene, which IS on the list at a rating of 3. Squalane vs squalene, and what the studies found.
- Glycerin also written as Glycerol
- No rating is published for it here. A humectant, and one of the most common ingredients in skincare.
- Meadowfoam seed oil also written as Limnanthes alba seed oil
- No rating is published for it here. An oil, on a list that carries 81 of them.
- Dimethicone
- No rating is published for it here. A silicone, used to give a product its slip.
Three of those are oils, on a list carrying 81 entries whose name carries the word oil. It is reasonable to read that as an oil nobody found a reason to rate, and it is still not a rating.
Squalane is worth a sentence of its own. The list carries Squalene, spelled with an e, at a rating of 3, and they are different substances: squalane is the hydrogenated form. Reading one as the other would give you a number for something you did not ask about, which is why the checker does not match them to each other.
What to do with an ingredient that is not here
Read the rest of the label. A product is a formula, and the ingredients that do carry a rating tell you more than the ones that do not. Where a rated ingredient sits in the list matters too, because the order is by descending concentration.
If an ingredient is missing and you want to know about it specifically, a dermatologist can answer questions this list cannot, and a patch test on your own skin answers the only question that is really about you.
Check a label against the list, or read where these ratings come from.
Common questions
- Does not being on the list mean an ingredient is safe?
- No. The list holds ingredients that carry a comedogenic rating here, so being absent from it means this site holds no rating for it, and that is a different statement from a rating of 0. It might be absent because it was tested and found not to block pores, or because nobody has tested it, and this site cannot tell you which.
- Why is glycerin not on the list?
- Because our list does not rate it. Fulton 1989, a paper this site cites, graded glycerin 0 in the rabbit-ear test, the only grade for it we have read. Our list does not carry that grade, so the checker reports glycerin as not on the list. Adding it would be a change to the list itself, and that has not been made.
- Will you add these ingredients?
- Only if a published rating for them turns up in the sources this site already cites. An ingredient is added only with a number from a published study.
The research on the method
- 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, Pay SR, Fulton JE 3rd. “Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear.” Journal of the American Academy of Dermatology, January 1984;10(1):96–105. (opens in a new tab) Rabbit-ear ratings of ingredients one by one, from the group whose 1989 tables this site cites. The grades shown on this site come from those 1989 tables and from Morris and Kwan 1983.
- 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.”
- U.S. Food and Drug Administration, “Cosmetics Labeling Claims”. (opens in a new tab) States that the FDA does not keep a list of approved or accepted cosmetic claims; a label must simply be truthful and not misleading. The page does not mention “non-comedogenic”, and a full-text search of the federal regulations on 31 October 2026 found no section using the word.