Browse skincare forums long enough and you'll come across comedogenic ratings, numbers from 0 to 5 attached to individual ingredients. But where do those numbers come from, and how much should they influence what you put on your face? This guide breaks down what the scale actually measures, where it falls short, and how to use it sensibly.
Cosmetic Dermatology · AAD Guidelines · Updated July 2026
A Two-Fold Principle
Two lenses for reading the scale
01. The Scale
0 to 5 — what each number means
Comedogenic comes from "comedo", the technical term for a blackhead or whitehead (a plugged follicle). A rating of 0 means an ingredient showed no pore-clogging tendency in testing; a rating of 5 means it showed a strong tendency. Every ingredient falls somewhere along that range.
02. The Context
Context matters more than the number
The ratings come from testing undiluted ingredients on an animal model, not from finished skincare products applied to human faces. How much of an ingredient is in a product, how it is blended, and how your particular skin responds can all shift the outcome significantly. The rating is a reference point, not a rule.
Where the comedogenic rating came from
In 1972, dermatologists Kligman and Mills developed a method to measure how readily cosmetic ingredients clogged pores. They applied undiluted ingredients to the inner ear skin of rabbits for four weeks and then examined cross-sections of the follicles under a microscope to measure blockage. That study introduced the 0-5 comedogenic scale that ingredient databases still reference today.
Over the following decades, more ingredients were tested and various researchers built on the original work. Because the methods were not fully standardized, you may notice the same ingredient listed at different ratings in different databases.
Reading the scale
Rating
Meaning
Examples
0
No clogging reported
Squalane, argan oil, some jojoba oil
1
Very low tendency
Rosehip oil, olive squalane
2
Low tendency
Jojoba oil, refined lanolin
3
Moderate tendency
Sweet almond oil, some sunflower oil
4
High tendency
Coconut oil, cocoa butter
5
Very high tendency
Isopropyl myristate, wheat germ oil
Ratings of 0-2 are generally considered low; 3 and above are often flagged as worth watching for acne-prone skin. That is a useful rough guide, though not a hard rule.
Three reasons the scale has real limits
1. Rabbit ear skin is not human face skin
The rabbit ear model used in the original testing has follicles that are far more prone to blockage than human facial skin. A 2006 review by Draelos and DiNardo published in the Journal of the American Academy of Dermatology noted that the rabbit ear model does not reliably predict responses in human skin. An ingredient that causes follicle plugging in a rabbit ear may behave quite differently on a person's cheek.
2. Undiluted versus diluted in a finished product
Testing uses an ingredient in its pure, undiluted form. In an actual skincare product, most ingredients are present at a fraction of that concentration and blended with many others. An ingredient sitting near the bottom of a product's ingredient list is likely present at 1% or less, which is very different from the pure form that was rated. Learning to read an ingredient list helps put this in perspective, see The Ingredient List and the 1% Rule.
3. Individual variation is significant
Not everyone responds to the same ingredient in the same way. Sebum output, follicle size, skin barrier condition, and hormonal factors all influence whether any given ingredient triggers comedones on a specific person's skin. Someone with very oily, acne-prone skin may react to an ingredient that someone with dry skin uses without any issue.
The truth about "non-comedogenic" labels
A product labeled non-comedogenic sounds reassuring. The problem is that this term is not regulated. Neither the Korean KFDA nor the US FDA has an official process for certifying this claim, so brands apply it based on their own standards, which vary widely. Some brands conduct independent consumer studies or dermatologist testing; others do not. Treat it as a useful signal, not a guarantee.
Ingredients that come up most often
Coconut oil (rating 4): Widely discussed in acne-prone skin circles. Worth being cautious about applying all over the face if your skin is prone to breakouts. Using it on lips, hair, or body is a different situation.
Cocoa butter (rating 4): A rich emollient that works well on dry skin areas and the body, but is often flagged for acne-prone facial skin.
Isopropyl myristate (rating 5): A texture-smoothing ingredient common in many formulations. If you have very acne-prone skin, checking ingredient lists for this one is reasonable.
Squalane (rating 0-1): A lightweight oil that mimics sebum and consistently rates very low for comedogenicity. Generally well-tolerated across skin types, including acne-prone skin. More detail in the Squalane Guide.
Jojoba oil (rating 2): Technically a liquid wax rather than an oil, with a structure that resembles sebum. Its low comedogenic rating makes it a popular choice for a wide range of skin types.
Editorial Tip
Check position, not just rating
"Where an ingredient appears in the ingredient list often matters more than its comedogenic rating. An ingredient near the bottom is present at very low concentration. For acne-prone skin, focus on what is in the top half of the list and look for lower-rated oils in key positions."
— Beauty Dupe Editorial
How to use comedogenic ratings practically
Check the key ingredients first: The ingredients listed early in a product's formula are present in higher amounts. If several ratings of 3 or higher appear near the top, that is worth noting for acne-prone skin.
Consider position in the list: Ingredients near the end of the list are often present at 1% or less. A high-rated ingredient in that position has limited influence compared to one near the top.
Match to your skin type: Oily and acne-prone skin tends to react more noticeably to high-rated ingredients. Dry or sensitive skin often has other priorities, like barrier support, where comedogenic ratings matter less.
Patch test to confirm: Ratings describe average tendencies across populations. Your skin's actual response is what matters. Before applying a new oil or rich cream all over your face, test it on a small area (the jaw or behind the ear) for one to two weeks. The Patch Test Guide covers the method in detail.
The Synthesis of Wisdom
Three ways to read a rating
Where the number came from, how it changes inside a product, and how your skin responds individually. All three together make the rating genuinely useful.
01. Origin
Where the number started
Comedogenic ratings came from a rabbit-ear animal model, testing ingredients in their undiluted form. Knowing this origin explains why the numbers are useful reference points but not hard rules for finished products on human skin.
02. Concentration
How dilution changes the picture
A rating of 4 for coconut oil in pure form tells you something different when that oil appears at low concentration in a blended cream. The ingredient's position in the ingredient list gives you a meaningful clue about how much is actually there.
03. Individual
Your skin's own response
Ratings reflect statistical tendencies across many people. They cannot predict how any one person's skin will respond. Patch testing remains the most reliable way to know whether a product works for your skin.
"
A comedogenic rating is a reference map, not a no-entry sign. The number gets more useful when you read it alongside ingredient concentration and observe how your own skin actually responds.
Beauty Dupe Editorial
Frequently asked questions
Should I avoid any product that contains a high-comedogenic ingredient?
Not necessarily. The ratings are based on undiluted ingredients, but in a finished product those ingredients are present at much lower concentrations and blended with others. Where the ingredient appears in the ingredient list, your skin type, and your own skin's reaction all matter more than the rating number alone.
Does a non-comedogenic label guarantee a product won't clog pores?
No. Non-comedogenic is not a regulated term. Neither the Korean KFDA nor the US FDA has an official certification process for this claim, so brands apply it based on their own judgment. It is a useful signal, but not a guarantee. Patch testing is still the most reliable way to find out how your skin responds.
Coconut oil has a high comedogenic rating. Should I stop using it on my face?
Coconut oil is generally rated around 4 on the scale. If you have oily or acne-prone skin, it is worth being cautious with it on the face. For dry skin, lips, hair, or body use, it tends to be less of a concern. Patch testing on a small area before full-face use is always a good idea.
Can people with acne-prone skin use facial oils?
It depends on the oil. Squalane (rated 0-1) and rosehip oil (rated 1) are often tolerated well by acne-prone skin. Oils with higher ratings, such as coconut oil or wheat germ oil, are worth avoiding on breakout-prone areas. The key is to check the rating and patch test first.
Skin Warning
If your skin is prone to breakouts, check the ingredient list before trying a new oil or rich moisturizer and patch test on a small area for one to two weeks. If acne becomes severe or keeps returning, consult a dermatologist rather than adjusting skincare alone.
References
Kligman AM, Mills OH Jr. "Acne cosmetica." Arch Dermatol. 1972;106(6):843–850.
Draelos ZD, DiNardo JC. "A re-evaluation of the comedogenicity concept." J Am Acad Dermatol. 2006;54(3):507–512.
American Academy of Dermatology — Acne Resource Center (skincare and cosmetics).
Korea Ministry of Food and Drug Safety — Cosmetic Ingredient Safety Standards.
Disclaimer · This guide is for general information only and does not replace individual skin assessment. If you experience persistent or worsening acne, stop use and consult a dermatologist.
