Most of us use skin-care products to support and promote the health and appearance of our skin. And with cosmetics, the intention is to enhance how we feel about our aesthetic in some way (not to mention that playing with makeup looks can be plain old fun and mood-boosting.) So, you probably wouldn’t want to knowingly use a product that would make you break out with acne, right? That’s where the concept of comedogenicity and non-comedogenic products comes in.
To break down what the word “comedogenic” means, consider that comedones are bumps caused by clogged pores. An open comedo, which is a single comedone, is a blackhead, and a closed comedo is a whitehead. “‘Comedo’ is the primary acne lesion, and ‘genic’ means to make,” says board-certified dermatologist Chris Adigun, MD, FAAD. “So ‘comedogenic’ essentially means acne-making.” On the flipside, an ingredient that’s non-comedogenic should not clog your pores.
But, classifying products as comedogenic or non-comedogenic isn’t so simple. There’s a variety of skin types, not every product will affect the same person’s skin the same way, and the way comedogenicity is tested is completely unregulated. But, you’re not without guidance. Here, pros— including dermatologists and a cosmetic chemist—break down what you should know in your pursuit to avoid breakouts and give advice for picking the best products for your skin.
Understanding Comedogenicity
“The term ‘comedogenic’ refers to the tendency of a substance to cause comedones, which are skin-colored small bumps—either whiteheads or blackheads—caused by clogged pores,” says board-certified dermatologist Robert Anolik, MD. “Products that are comedogenic can exacerbate acne by blocking pores, leading to more breakouts.” This is especially true for people who have oily or otherwise acne-prone skin, he adds
But “can exacerbate acne” crucially doesn’t mean “will.” As Shereene Idriss, MD, a board-certified dermatologist in New York City, says, “just because an ingredient is comedogenic on its own does not mean that it is comedogenic in a product. Ultimately, the dose makes the poison.”
Think about cold brew concentrate: It’s designed to be diluted in a certain amount of water before you pour a glass and drink up. But if you don’t dilute it first, your drink will be much stronger, and you’ll be subject to more intense effects of caffeine consumption. Similarly, the potency of a comedogenic ingredient in a cosmetic or skin-care product has to do with its concentration in the formulation, how comedogenic the ingredient is in the first place (more later on the comedogenicity scale of 0 to 5), and the overall blend or emulsion of the product.
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“Even if you use ingredients that are comedogenic on their own, once they are in an emulsion, they can take on different properties and the final formula may not be comedogenic,” says cosmetic chemist Krupa Koestline. So while certain ingredients might be comedogenic in their own right and in certain concentrations—like coconut oil, algae extract, and lanolin—just because they appear somewhere on your product’s ingredient list doesn’t mean you’re doomed to a breakout.
Furthermore, even if an ingredient is comogenetic, you might not break out after using it—but it doesn’t mean your best friend would necessarily be in the clear with you. “Not all skin is created equally,” says Dr. Idriss. “Your skin chemistry plays a role in determining the comedogenicity of an ingredient [as it applies to your skin].”
How Comedogenicity is Tested
Just to be clear from the jump, testing on comedogenicity is both limited and flawed—it’s kind of like the Wild West of beauty. The Federal Drug Administration (FDA) doesn’t regulate the testing practices, nor is there any mandate to test for comedogenicity at all. So—as is the case with the unregulated vitamins and supplements industry in the United States—you likely shouldn’t take any proclamations about a product being non-comedogenic as gospel.
Moving from that disclaimer, there is a growing body of research on comedogenicity that various companies and brands opt into with their testing trials. (Though, again, the tests themselves aren’t standardized, so results are not, either.)
Early testing in the ‘70s and early ‘80s was largely conducted on rabbit ears, which is where the comedogenicity scale of 0 to 5 was born. In light of a number of issues—namely an intentional move away from animal testing, and the reality that rabbit and human skin are not identical—there’s since been a shift toward human skin testing trials.
Limitations and controversies of animal testing, overview of rabbit ear assays (REAs) and their relevance
Rabbit ear assays (REAs) made up the earliest form of testing for comedogenicity. Scientists “would apply the ingredient on the rabbit ear and then see whether any comedones formed [over time],” says Koestline. “This would tell us whether something is comedogenic or not.”
In addition to a move away from animal testing for ethical reasons, the introduction of human skin testing for comedogenicity was welcome because rabbit ear skin and human face skin aren’t the same.
Early human testing found rabbit ears to be more sensitive than human skin. Substances deemed weakly comedogenic based on rabbit-ear testing results didn’t necessarily lead to comedones on humans. Meaning, the results of the rabbit studies don’t always reflect a trusted human reaction.
Human skin testing and its significance
Human skin testing is also not perfect, largely for the same reasons of lacking regulation and standardization of tests. Furthermore, the tests aren’t typically conducted on facial skin. “Testing is done on the back, not on the face,” says Koestline. “Clearly there were limitations [with rabbit ears, because] rabbit ear skin is not comparable to a human facial skin. The skin on your back is also different from the skin on your face.”
Identifying Non-Comedogenic Products
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First, Dr. Idriss cautions against tossing out all the products in your makeup bag and bathroom cabinet out of worry for comedogenicity. “If you’re using a product and it works well for you, don’t cut it out simply because the ingredients are comedogenic,” she says.
Reading product labels and ingredient lists
An awareness of certain common comedogenic ingredients is helpful for reading labels of products that are irritating you—but it’s also important to pay attention to where a given substance lives on the list. “If you’re breaking out and not sure why, identifying products in your routine with comedogenic ingredients that are high up on the ingredient list is a good starting point,” says Dr. Idriss. “Ingredients beyond the first five in the list are not significant.”
Common non-comedogenic ingredients
Since Dr. Idriss says a great many ingredients are non-comedogenic, it’s perhaps more helpful to know which ingredients are more likely to clog pores and to avoid those. However, “common non-comedogenic ingredients include hyaluronic acid and glycerin,” says Dr. Anolik. “These ingredients are less likely to clog pores and can be beneficial for maintaining clear skin.”
He adds that looking out for labels on products can be helpful signposts: In addition to the clear “non-comedogenic” stamps, some products might also include designations like “won’t clog pores” or “oil-free,” he says.
The role of comedogenic ratings (0-5 scale)
“Comedogenic ratings range from 0 to 5, with 0 being non-comedogenic and 5 being highly comedogenic,” says Dr. Anolik. “However, these ratings are not absolute and can vary based on individual skin types. A product with a rating of 2 might be safe for one person but cause breakouts in another. So use it as a guide.”
Dr. Idriss agrees: “The ratings are not a representation of real-world experiences; don’t let them be a major factor in selecting the right products for your skin. As always, patch test first and if it works for you, it works.”
Other Tips to Consider for Acneic Skin
If you know you’re acne-prone or have oily skin, and you’re not sure how to shop for skin care and cosmetic products that’ll keep irritation at bay, it’s always a good idea to consult your dermatologist.
Dr. Adigun says she has a printout of products she commonly recommends to patients struggling to find options that work for them. Any dermatologist should be able to provide personalized guidance to help you navigate the beauty aisle (jot down tips if your provider doesn’t give you a cheat sheet of their own).
Doing an at-home version of patch testing a product is another safe bet for protecting yourself from irritation. To do it, the American Academy of Dermatology Association (AAD) recommends applying the product twice a day for seven to 10 days to a quarter-sized space on your body. (The AAD suggests the bend of your elbow or underside of your arm, but anywhere it won’t rub off will work.) If you develop a rash or reaction, wash the product off and stop using it. If you’re clear after the testing window, you can confidently use the product in your routine—regardless of whether or not there are comedogenic ingredients in the formulation.
The Bottom Line on Comedogenicity
Unfortunately for those of us who feel most set up for success when armed with a defined set of guidelines to follow, comedogenicity isn’t so clear-cut. In addition to the testing process being unregulated and uncontrolled, the ingredients themselves will affect all folks differently.
“Skin care is highly individual,” says Dr. Anolik. “What works for one person might not work for another. It’s essential to listen to your skin and adjust your routine as needed. Consulting with a dermatologist can provide personalized advice and help you find the best products for your skin type.”
