The comedogenic scale is a simple idea doing a surprisingly hard job. It tries to put a single number, from 0 to 5, on how likely a cosmetic ingredient is to block a pore. A blocked pore traps oil and dead skin into a plug called a comedone — the blackheads and whiteheads that start most breakouts. Rate every ingredient in a product, and you get a quick read on whether that product is likely to sit lightly on the skin or contribute to congestion.
The numbers we use trace back to dermatologist James Fulton, who in the 1980s tested ingredients on the inside of rabbit ears and scored how much they clogged the follicles. Everything from 0 to 2 is generally treated as non-comedogenic; a 3 is the moderate middle; a 4 or 5 is high-risk. Because the word “non-comedogenic” has no legal meaning on a label, the actual ingredient ratings are what tell you the real story.
Why makeup deserves the same scrutiny as skincare
Skincare gets most of the attention in comedogenic conversations, but complexion makeup can be a bigger factor for congestion. Foundations, primers, concealers, and cream products sit on the skin for eight to twelve hours, often layered and re-applied, exactly the conditions in which a moderately comedogenic ester or oil has time to do its work. Many of the highest-rated ingredients on the scale — isopropyl myristate, isopropyl palmitate, and various myristate esters — are texture agents used precisely because they make makeup feel silky. That is why this checker treats makeup and skincare the same: paste either, and every recognised ingredient gets rated.
How to read your result
When you paste a list, the checker sorts what it finds by risk and shows a badge for each ingredient: green for 0–2, amber for 3, red for 4–5. It also reports an average rating across the recognised ingredients, which is a handy at-a-glance signal — though a single red-flagged ingredient near the top of the list can matter more than a low average. Where credible sources disagree on a score, we show the range and mark the ingredient disputed rather than pretend there is one clean answer.
Two caveats keep the tool honest. First, concentration: ingredients are listed in descending order, so a high-rated ingredient near the end of a long list is usually present in trace amounts. Second, formulation: a finished product can behave differently from its parts. Read the ratings as a screening step that tells you which products are worth a closer look, then let your own skin have the final say.
Frequently asked questions
What is a comedogenic rating?
A comedogenic rating is a 0–5 score describing how likely an ingredient is to clog pores. 0 means it won't clog pores for virtually anyone; 5 means it very likely will when used at meaningful concentration. The scale comes from Fulton's comedogenicity studies and the lists derived from them.
What counts as non-comedogenic?
Ingredients rated 0, 1, or 2 are generally considered non-comedogenic and low-risk. There's no legal definition of the word 'non-comedogenic' on packaging, which is exactly why checking the actual ingredients is useful.
Does this work for makeup as well as skincare?
Yes. Foundations, primers, and other complexion makeup are common culprits for congestion because they sit on the skin for hours. Paste any makeup or skincare ingredient list and the checker rates each recognised ingredient.
How reliable is the 0–5 scale?
It's a useful guide, not a guarantee. The ratings come from tests on single ingredients at high concentration, and a finished formula, the amount used, and your own skin all change the outcome. Use the score as a flag, not a verdict.
Is my ingredient list private?
Completely. The checker runs entirely in your browser. Nothing you paste is uploaded, stored, or shared.
This tool is for general information only and is not medical advice. For persistent or severe acne, consult a dermatologist.