Pore-clogging ingredient checker

What makes an ingredient pore-clogging?

A pore clogs when dead skin cells and oil build up inside the hair follicle instead of shedding out, and harden into a plug called a comedo. An open one is a blackhead; a closed one is a whitehead. Some ingredients seem to speed up that build-up, and dermatologists call them comedogenic. Our guides to what clogged pores look like and closed comedones show the difference.

Most of what we know comes from the rabbit ear test. In the version James Fulton used for his 1989 table of skin care ingredients, each ingredient was mixed at 10% into propylene glycol and spread on the inside of a rabbit’s ear five days a week for two weeks. The follicles were then measured and graded from 0 to 5. Many of the comedogenic ratings you find online trace back to that table.

Rabbit ear skin reacts far more than yours. Its outer layer is thin and underdeveloped, Fulton noted, and when Mills and Kligman compared it with a human test on the back, the rabbit was the more sensitive of the two. They also found that ingredients graded moderate to strong in rabbits did cause comedones in people. So the high grades are worth taking seriously, and the weak ones much less so.

Why a grade isn’t a verdict on a product

A grade describes one ingredient at one strength. A product mixes dozens, each at its own strength. When Draelos and DiNardo tested finished products on people prone to clogged pores, they concluded that products made with comedogenic ingredients are not necessarily comedogenic.

Petrolatum is the best-known false alarm. Early rabbit reports called it comedogenic, then Kligman’s 1996 study had 20 people with acne apply it twice a day for eight weeks and found no sign of clogging. A 2024 review in the Journal of the American Academy of Dermatology calls the belief that it causes acne a misconception. Our article on whether Vaseline clogs pores covers the details.

The lists still mean something. In a 2025 case-control study of 151 people, cleansers that contained comedogenic ingredients were tied to a higher risk of acne. That is a link, not proof of cause, but it is a good reason to read the list if you break out easily.

Pore-clogging ingredients list

These are the 141 ingredients the checker knows, with the grade each one got in Fulton’s rabbit ear table and any evidence from people. Search by any name you see on a label, Latin names included, or filter by grade. A range like 0-2 means the result changed with the source of the raw material.

“None” means no test gave a grade: shea butter is listed for a dermatologist’s caution, and petrolatum for the studies on people. Ingredients that appear on many lists online were left out when we couldn’t trace their rating to a published test.

How to read an ingredient list for pore-cloggers

Ingredients must be listed from the largest amount to the smallest, but anything at 1% or less can go in any order after that, and colors can go last in any order, according to the FDA’s cosmetics labeling guide. So a flagged ingredient near the top is a bigger share of the formula than one near the end.

• Find the 1% line. Phenoxyethanol, a very common preservative, is capped at 1% in EU cosmetics, a limit the EU’s scientific committee on consumer safety reviewed and upheld. Whatever is listed after it is likely at 1% or less. The checker marks this line for you.
• Read “may contain” on its own. Makeup sold in shades lists the colors that are only in some shades after “may contain” or “+/-”. Their place in the list says nothing about how much is there.
• Expect Latin and older names. Coconut oil appears as Cocos Nucifera Oil, shea butter as Butyrospermum Parkii, and “octyl” is the older name for “ethylhexyl”. The checker matches these for you.
• Think about how you use it. A cream left on all night is a different exposure from a cleanser that rinses off in a minute, though the 2025 study above still linked cleansers to breakouts.

Many popular actives, like niacinamide, were never graded at all. For how they work and which ones combine well, see what niacinamide does and which skincare ingredients you can mix.

Who should check for pore-clogging ingredients?

It matters most if you get blackheads, whiteheads, or small skin-colored bumps, the comedonal kind of acne. If you break out along your hairline and forehead, check your hair products too. The American Academy of Dermatology says oils in shampoos, conditioners, and styling products can cause tiny breakouts there, and that it can take 4 to 6 weeks to clear after you stop. Our guides to small bumps on the face, getting rid of whiteheads, and what your acne’s location can tell you help you work out what you’re seeing.

If your skin rarely breaks out, a borderline ingredient is unlikely to change that. Mills and Kligman judged that ingredients with weak reactions in rabbits are unlikely to cause problems for people, with acne-prone skin the possible exception. Dry skin often needs exactly the rich oils and butters that grade high, and if you don’t clog, there is little reason to avoid them. An occlusive layer at night, known as slugging, can help too.

Gray dots on your nose that come back days after you squeeze them are usually sebaceous filaments, a normal part of the pore, and avoiding ingredients won’t make them go away.

If a product seems to break you out

1. Stop the newest product first. Clogged pores tend to appear a few weeks after you start something, in the areas where you apply it most.
2. Add products back one at a time, a few weeks apart, so you can tell which one did it.
3. Take your makeup off every night. Even non-comedogenic makeup can cause acne if you sleep in it, the AAD warns.
4. Treat the clogs, don’t just avoid ingredients. Salicylic acid, benzoyl peroxide, azelaic acid, and retinoids all help clear comedones, as DermNet’s guide to comedonal acne explains. Our guides to getting rid of blackheads and getting clear skin show how to start.

If your breakouts are deep, painful, or don’t settle with over-the-counter care, see a dermatologist. Once you know which products you’re keeping, the skincare routine builder puts them in the right order, morning and night.

How this ingredient checker works

Paste a list and the checker splits it into ingredients however it was copied: commas, line breaks, slashes, Latin names with the common name in parentheses, drug facts boxes, and “may contain” sections. It matches each ingredient against the table above, then shows where it sits using the labeling rules, without guessing percentages. It never gives a product a score, because the evidence can’t support one. Everything happens in your browser.

Ingredients tell you what could clog. To see what your skin is actually doing, track it in the same light over a few weeks, or use an AI skin analysis that scores pores and acne from a selfie.