- Every flag has a named source
- Your list stays in your browser
- Free, no sign-up
What to do next
- Patch-test first Try a new product on a small area.
- Give it a few weeks Skin takes time to show changes.
- See a doctor if it hurts Painful or widespread acne needs care. Read about acne: NHS · AAD
Not medical advice. Flags are a screening aid, not a diagnosis. The amount and the formula both matter.
What the numbers mean
Each result shows the highest rating any source gave, from 0 to 5, from lab tests of the raw ingredient. More about the scale.
| Rating | Band | A study at this rating |
|---|---|---|
| 0 | None | Doesn’t flag it |
| 1 | Low | Doesn’t flag it |
| 2 | Low | Flags it, rated low |
| 3 | Moderate | Flags it: may clog pores |
| 4–5 | High | Flags it: may clog pores |
How to check a product
- Find the list. On the box, the back label, or the product's web page, under "Ingredients".
- Copy it. Copy the whole list from the web page, or type it from the box.
- Paste or type it above. Pasting checks it right away. If you typed it, press Check. Results come in label order.
- The list starts after "Ingredients". On a box, it’s often on the back or bottom. Online, look for an "Ingredients" tab. On a Drug Facts box, copy both the active and the inactive ingredients.
- Higher on the list usually means more of it. Ingredients are listed from most to least. (On some acne treatments, the inactive list goes A to Z instead.)
- Below about 1%, the order is free. Ingredients near the end may come in any order.
Where the ratings come from
255 ingredients have data so far. 204 of them have a rating from a lab study we read in full: Fulton 1989 and Morris & Kwan 1983. These studies tested ingredients on rabbit skin, which reacts more than human skin. 51 are named only by published lists, which give no number.
Each result shows every source's rating or flag and how many agree. The studies often disagree, partly because they tested in different ways. We never add a rating from memory. See every source and its limits →
Checking for fungal acne?
"Fungal acne" is the common name for Malassezia folliculitis, caused by a yeast growing in hair follicles. It is different from clogged pores. Our fungal acne checker shows what lab tests found for 71 ingredients, and which yeast species grew on each.
Common questions
Is this checker free?
Yes. There is no sign-up, and the check runs in your browser, so your ingredient list is never sent to us.
Where do the ratings come from?
From 2 lab studies we read in full and 2 published lists. Every result names its source and shows how many sources agree.
Does "not on any list" mean an ingredient won’t clog pores?
No. It only means none of our sources name it. Our sources cover 255 ingredients, so a missing flag doesn’t mean an ingredient can’t clog pores.
Can it check for fungal acne?
It can check a list against lab tests of the fungal-acne yeast, on the fungal acne checker. It can’t tell you whether you have fungal acne; a doctor can.