How Our Ingredient Checker Works
Transparency is our top priority. We know that choosing skincare is personal and can often be overwhelming. Here is the whole method, including the parts that are less impressive than a marketing page would make them sound.
What actually happens when you press the button
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Your list is split into ingredients
The text you paste is split on commas, semicolons and line breaks, then each piece is lower-cased and stripped of punctuation. Nothing leaves your browser: the whole ingredient table is delivered with the page, so there is no request to a server and no record of what you checked.
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Each piece is matched by name, not guessed at
A label might say Coconut Oil, or Cocos Nucifera, or Coconut Oil (Cocos Nucifera). The table carries 395 name variants across its 285 entries, including botanical names and the forms that appear inside brackets, so all three find the same row. Matching is exact against that set. A near-miss is reported as a near-miss, and an ingredient we hold no rating for is reported as unknown rather than estimated.
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The rating shown is the one published on this site
Every number comes from the A–Z list, which is the same list this site has published since February 2026; where it came from is set out on the about page. Some entries are a range instead of a single figure, as the list gave them; 103 of the 285 entries are. No rating is generated, inferred or rounded.
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What it deliberately does not do
It does not check allergens, fragrance sensitisers, preservatives, irritancy or pregnancy safety. It does not rank your product or tell you to stop using it. It cannot see concentrations, because labels do not print them, and it cannot predict how a finished formula behaves, because the scale rates raw ingredients tested alone.
How the Analysis Happens
Find Your Ingredients
Locate the ingredient list on your product’s packaging or the "Full Ingredients" section of a retailer's website.
Copy and Paste
Select the entire text and paste it into our Interactive Ingredient Checker.
Instant Analysis
Our algorithm scans the text against our database of known pore-cloggers.
Review Your Results
See an instant breakdown of every ingredient with its corresponding 0-5 comedogenic rating.
Independent, in the only sense that can be checked
There is nothing to buy on this site, no affiliate link, no sponsored placement and no brand paying to move a number. That is not a promise about our character, it is something you can verify by looking: there is no shop.
If a rating here looks wrong to you, that ingredient's own page says whether we could trace it to a paper, and names the paper and its grade where we could. You can read what we found and judge it for yourself rather than take it on trust, which is the only kind of independence anyone can actually check.
Frequently asked questions
How do I find the ingredient list for my skincare product?
The easiest way is to look at the physical packaging or the brand’s official website under the “Ingredients” or “Full Formula” tab. You can also search for your product on major retailer sites, then copy and paste the text directly into our pore clogging checker.
Why should I use a checker if my product is labeled "Non-Comedogenic"?
The term “non-comedogenic” is not strictly regulated by the FDA. Many brands use it as a marketing claim even if the product contains ingredients with a high rating on the comedogenic scale. Using a dedicated non-comedogenic checker gives you an unbiased, scientific look at what’s actually in the bottle.
Is a product safe if it only has one or two pore-clogging ingredients?
If you have highly acne-prone skin, even a single high-rated ingredient (Rating 3–5) can trigger a breakout. However, the concentration matters: if a pore-clogger is at the very bottom of the list, it might be less reactive. For best results, we recommend sticking to products that score a “0” on our acne ingredient checker.
Which types of products are most important to check?
You should prioritize checking “leave-on” products that stay on your skin all day, such as moisturizers, sunscreens, and foundations. These have the longest contact time with your pores. Rinse-off products like cleansers are generally less likely to cause issues, but still worth a quick scan.
Do you have product guides?
Yes. Our guides read each product’s ingredient list against the pore-clogging list and say what they found. Nothing on them was tested by us. Check out our guides for the Best Non-Comedogenic Moisturizers and Best Non-Comedogenic Sunscreens to build a routine.
Does the order of ingredients on the label matter?
Yes! Ingredients are listed in descending order of concentration. The first 5 to 7 ingredients usually make up about 80% of the product. If a pore-clogging ingredient is in the top 5, it is much more likely to cause a breakout than if it is the very last ingredient on the list (where it may be present at less than 1%).
What is the difference between "Comedogenic" and "Acnegenic"?
While often used interchangeably, they mean different things. Comedogenic ingredients cause “comedones” (blackheads and whiteheads) by physically blocking the pore over time. This can take weeks or months to show up. Acnegenic ingredients cause an immediate inflammatory reaction or irritation (red pimples) within days of use. Our acne ingredient checker screens for both types of triggers.
Sources
- Kligman AM, Mills OH Jr. “Acne cosmetica.” Archives of Dermatology, December 1972;106(6):843–850. (opens in a new tab) The paper that named cosmetic acne and started the search for which ingredients cause it.
- 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.
- Mills OH Jr, Kligman AM. “A human model for assessing comedogenic substances.” Archives of Dermatology, November 1982;118(11):903–905. (opens in a new tab) The human back-skin model, developed because the rabbit ear was known to overstate the risk.
- 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. It is behind a paywall and we have not read it, so no rating on this site is attributed to it.
- 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) Found that animal-model results did not reliably predict what happened on human skin, and that a rating for a single ingredient does not tell you how a finished product will behave.
- 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. There is no FDA definition of “non-comedogenic” for a brand to meet.