Comedogenic Ratings Are Nearly Useless

Type “is coconut oil comedogenic” into any search bar and you’ll get a confident answer: 4 out of 5, highly likely to clog pores. That number comes from a single 1970s study on rabbit ears. Not a face. Not a formula. An ear, on a rabbit, tested with raw ingredients at full strength.

That’s the problem with comedogenic ratings in a sentence. The scale most of us grew up trusting was never designed to predict what happens when a product touches your skin. It was designed to screen raw materials for an animal model that doesn’t metabolize sebum the way humans do. Everything built on top of that — the charts, the apps, the “avoid these 12 ingredients” lists — inherits the same flaw.

We’re not saying pore-clogging ingredients don’t exist. They do. But the rating you’re relying on to avoid them is doing far less work than you think.

Where the 0-5 Scale Actually Came From

The comedogenic scale traces back to research from the 1970s and 80s, most of it using what’s called the rabbit ear assay. Researchers applied a raw ingredient directly to the inside of a rabbit’s ear, repeatedly, over several weeks, then checked for follicular plugging under a microscope.

Rabbit ear skin is a reasonable stand-in for some things. It is not a reasonable stand-in for human facial skin. Rabbit ears have a different follicle density, a different lipid composition, and they respond to occlusion far more dramatically than human skin does. Ingredients that scored high on rabbits — including isopropyl myristate and some fatty acid esters — have since been tested on human skin in controlled studies and shown little to no comedogenic effect at the concentrations actually used in finished products.

Dermatologist James Fulton, who ran much of this early work, later tried to standardize testing on human backs instead, applying ingredients under occlusive patches. That version is closer to reality, but it still isolates a single raw ingredient from the formula it would actually ship in. And the human-patch studies were inconsistent enough across labs that no single agreed-upon scale ever emerged. The numbers you see floating around skincare apps and ingredient databases today are a patchwork pulled from several different studies, different decades, different methods, and sometimes different species.

Why This Matters for How You Shop

When three different databases disagree on whether an ingredient is a 2 or a 4, that’s not a typo. It reflects the fact that there’s no unified testing standard behind the number at all. If you’ve ever compared how to read skincare ingredient labels across sites and gotten conflicting comedogenic scores for the same oil, this is why. You’re not misreading the data. The data itself was never standardized.

The Finished Formula Problem

Here’s the part that gets lost in every “comedogenic ingredients to avoid” listicle: nobody wears raw coconut oil on their face. They wear a moisturizer that’s maybe 2% coconut-derived emollient, buffered by silicones, humectants, and a handful of other ingredients that change how everything behaves on skin.

Concentration changes everything. An ingredient tested at 100% in a rabbit ear assay behaves nothing like that same ingredient at 3% in a cream, diluted among a dozen others. Comedogenicity isn’t a fixed property of a molecule — it’s a function of how much of it reaches the follicle, how occlusive the full formula is, and how it interacts with everything else in the bottle.

Interactions matter too. A formula with cocoa butter (often flagged high-comedogenic) might also contain niacinamide, which helps regulate sebum, or a humectant system that keeps the product from sitting heavy on skin. The final texture — how it spreads, how fast it absorbs, whether it forms an occlusive film — depends on emulsification and the full ingredient matrix, not on any one component’s standalone rap sheet.

This is why you’ll find people who break out from “non-comedogenic” labeled sunscreens and people who use straight-up coconut oil with zero issues. The rating on the bottle, or the one you looked up separately, was never measuring the thing you actually put on your face.

The Oil Databases Can’t Agree On

Search “is argan oil comedogenic” and you’ll get ratings ranging from 0 to 3 depending on the source. Same ingredient, wildly different scores, because different labs tested different purity levels, different carrier conditions, and different endpoints for what counted as “clogged.”

If you want a framework that’s actually predictive for facial oils specifically, skip the comedogenic chart and look at fatty acid composition instead. Oils high in linoleic acid tend to be thinner, absorb faster, and are associated with fewer breakouts in observational data. Oils high in oleic acid tend to be heavier and more occlusive, which can be great for very dry skin and less great if you’re acne-prone. We broke down the actual ratio data in our linoleic vs. oleic face oil guide, and it’s a far better predictor than any 0-5 number you’ll find floating around.

Grapeseed oil, for example, sits at a favorable linoleic-to-oleic ratio and tends to feel light enough for oilier skin types — which is part of why it shows up so often in lists built for that skin type.

If your skin leans oily or acne-prone and you’re nervous about oils in general, our guide on face oils for oily, acne-prone skin walks through which fatty acid profiles tend to behave, regardless of what a comedogenic chart says.

What Actually Predicts Breakouts

Since the ingredient-level number isn’t reliable, the better question is: what does predict whether a product will clog your pores?

Your own skin history. The single best predictor of whether a product will break you out is whether products with a similar texture and occlusion level have broken you out before. This is more useful than any database.

Texture and finish, not ingredient lists. A heavy, tacky, slow-absorbing product is more likely to sit on the skin surface and trap debris than a fast-absorbing one, regardless of which emollients are inside it. If a moisturizer leaves a film on your skin twenty minutes after application, that’s worth noting.

Patch testing on your actual jawline, not your wrist. Comedones form in the pilosebaceous unit, which is denser on the face, chest, and back than almost anywhere else on the body. A patch test on your forearm tells you about irritation risk. It tells you very little about pore-clogging risk, because your forearm doesn’t have the follicle density your T-zone does. If you want the full method for testing new products properly, we cover it in our guide on how to patch test — the short version is: test on the jawline or behind the ear for two weeks, not the inner arm for two days.

Known offenders in high concentration. This part of the old research did hold up reasonably well: lauric acid, myristic acid, and certain isopropyl esters at high concentrations in occlusive bases have decent evidence behind them as pore-clogging in some people. The caveat is always “at high concentration in an occlusive base” — not “anywhere this ingredient appears on a label.”

What’s actually forming the bumps on your face already. A lot of what people call “clogged pores” from a new product is actually sebaceous filaments, which are a normal, permanent skin structure and not something any product formula caused or can fully remove. Worth ruling that out before you blame the moisturizer.

What To Do Instead of Checking the Scale

Stop Googling individual ingredients and start evaluating formulas as a whole. A few concrete habits:

Buy from brands that do their own non-comedogenic testing on the finished product, not just the raw ingredients. This is usually disclosed on the product page or in the clinical claims section, and it’s a genuinely useful signal, because it means someone tested the thing you’re actually going to put on your face.

Introduce one new product at a time, for at least two to three weeks, so you can actually attribute a breakout to its source. Comedones take two to six weeks to form and surface, so a breakout on day three almost never means what people assume it means — it’s more likely irritation, purging, or something unrelated entirely.

If you’re oil-curious but worried about weight and clog risk, look at the finished product’s absorption speed and your own skin type rather than a comedogenic number pulled from a different ingredient’s standalone study. Lighter, faster-absorbing oils with favorable linoleic ratios — squalane is a solid example, since it’s structurally identical to the squalene your skin already produces and sits at the low-occlusion end of the spectrum.

If you want an oil-based option that pairs vitamin C with a lighter, non-mineral-oil base, Kerala Botanics’ Ayurvedic Vitamin C Face Oil is worth a look. It combines a stabilized, oil-soluble vitamin C with bakuchiol in a plant-oil base, which makes it a reasonable all-in-one swap for a serum-plus-moisturizer routine. The honest caveat: it’s still an oil, and if your skin runs very oily or you’re prone to breakouts around the hairline and jaw, any facial oil — regardless of its comedogenic reputation — can feel like too much. It’s also worth noting the clinical backing here is thinner than something like SkinCeuticals C E Ferulic, so if you need trial-level evidence behind a vitamin C product, that’s a factor to weigh.

Putting It All Together

The comedogenic scale isn’t fake, exactly. It’s just measuring the wrong thing, on the wrong animal, at the wrong concentration, for a question you’re actually asking about a finished product you’ll use on your own particular skin. Treat a 0-5 rating as trivia, not instruction.

What actually helps: check if a brand tested the finished formula, not just its ingredients. Patch test on your jawline, not your wrist. Give new products several weeks before you draw conclusions. And if you’re evaluating oils specifically, learn the linoleic-to-oleic ratio — it’s a better predictor than anything you’ll find on a comedogenic chart, rabbit ears included.