Comedogenic and acne-triggering cosmetics Q&A

Yes. There are two different ways in which cosmetics can contribute to your acne and clogged pores:

1. Irritation: cosmetics can cause skin irritation. This means that the skin becomes more inflammation-prone and inflamed acne spots are more likely to appear. Any cosmetic product that causes irritation makes the skin more acne-prone.

   For example, you might have read that seaweed (algae) in cosmetics can trigger acne. It is possible, but it is not because seaweed is comedogenic. Seaweed has high content of iodine, and iodine can make skin more prone to inflammation, which can lead to an acne breakout.

2. Pore clogging. Cosmetic ingredients mix with our natural skin sebum. This mixture then undergoes the influence of UV light, oxygen and air pollution. The resulting substance can be more likely to clog pores. This process is complex and depends on many factors, including the starting composition of your skin sebum (and it varies for different people and even for the same person, for example, for females depending on the time of their menstrual cycle). Ingredients that increase pore clogging for one person often do not have the same effect on another one.

   It is true that some ingredients have a higher risk of increasing pore clogging. The problem is that we almost never use a pure ingredient on our skin. In most cases, it is mixed with other ingredients. This mixture can be more or less pore-clogging than the pure ingredient. Existing comedogenicity (pore-clogging) ratings test pure or diluted single ingredients. This is why these ratings are not very helpful in predicting the pore-clogging risk of products that contain them. Theoretically, of course, just the fact that a product includes some concentration of an ingredient that on its own is pore-clogging makes the risk that the resulting product can clog pores higher. However, a product can contain a comedogenic ingredient but still not increase pore clogging in practice.

Highly unlikely. Some medications can cause acne as a side-effect, but topical cosmetics are almost never the main cause of acne.

Skin pores (or in proper medical terms, follicles) get clogged when skin debris mixed with skin oil get sticky and stay on the surface inside the pore instead of getting shed outside. Over time (2-3 weeks), the sticky debris mixture accumulates inside the pore. The pore gets slightly enlarged and a microcomedone is formed. It is still called “micro” because it is under the skin surface and is not visible to a naked eye. Acne-triggering bacteria start to grow fast inside the pore. Tiny growing hair can get trapped inside the pore. In 2-4 more weeks, the microcomedone can grow into a mature comedone that is visible to a naked eye either as a closed comedone (small bump on the skin surface) or as a blackhead (an open comedone). If the skin inside the pore becomes irritated by the growing acne bacteria, an inflamed acne spot appears.

An important point: the initial “stickiness” of the mixture of the skin debris and oil inside the pore is not caused simply by the presence of the oil. The oil (skin lipids) are needed for the normal shedding of the dead skin cells from inside the pores. (That’s why “drying your skin out” does not work against acne). The problem seems to be that the chemical composition of the oil needs to be right to facilitate the normal shedding process. For example, studies show that people who are prone to comedones have less linoleic acid in their skin sebum compared to the sebum of comedone- and acne-free skin. The skin sebum composition is under a strong influence of hormones and complex biological processes inside the skin that have little to do with the cosmetics we use (even though some actives like Retinoids and Niacinamide can impact these biological processes).

Substances we put on the surface of our skin as part of cosmetic products can slightly change the total composition of the oil on the skin surface. Their effect on the oil composition inside the pores is even smaller though. This is why cosmetic products are rarely the main cause of comedone formation and acne.

No, but there is a connection. Comedogenicity is about whether an ingredient or a product contributes to pore clogging. Clogged pores can result in more inflamed acne spots. (Acne-triggering bacteria thrive inside the clogged pores. If there becomes too many of them, the skin becomes irritated by the byproducts of their activity and can react with inflammation in the pore). Acnegenicity is about whether the product contributes to the development of inflamed spots, either through the pore clogging, or by increasing the skin inflammation directly. In other words, acnegenic products might not clog pores, but still make you more likely to get inflamed pimples because they cause irritation inside the pores.

For ease of use, we included both potentially comedogenic and acnegenic ingredients in the What’s In My Jar search filter for comedogenicity. When using the filter, please keep in mind its serious limitations: it is impossible to tell for sure if a product will be comedogenic or acnegenic for you solely based on the ingredients it contains. Irritant skin reactions are individual. The same is true for pore clogging: whether or not a product or ingredient will clog your pores depends on your individual skin factors (size of your pores, rate of keratin production, speed of dead skin cell shedding) and the chemical composition of your natural skin sebum.

The American Academy of Dermatology advises to take ingredient comedogenicity ratings with caution. If an ingredient shows as comedogenic in tests, it only indicates that there might be a risk that it might increase pore clogging in practice. And this is true only when the ingredient is used in the same concentration as in the tests (and tests tend to use the 100%, 50%, 25% concentrations - way higher percentages than used in real cosmetic products). Knowing the comedogenicity rating for an ingredient in 100% concentration tells you almost nothing about its comedogenicity in 1% concentration.

We do not recommend using the comedogenicity ingredient filter by default when searching for skincare products. Apply it only if you know that you get clogged pores from cosmetics easily and want to minimize the risk as much as possible. The downside of minimizing the risk this way is that you might filter out a lot of good products with effective actives that include only a tiny concentration of an ingredient that can be comedogenic when used pure. Please be aware that the product that doesn’t contain any comedogenic ingredients can still contribute to pore clogging (this is because the resulting product mixture can be comedogenic even when individual ingredients are not).

For most people, it makes more sense to look at the product irritancy risk and, wherever possible, go for products with less common irritants.

These labels are marketing claims. Unfortunately, they do not guarantee that the product indeed does not contribute to pore clogging or acne. Manufacturers making such claims do have to have some test results to confirm them (the word that the industry uses is “to substantiate the claim”), but there is no common methodology or requirements for such tests. This means that one brand can make this claim after testing their product with 5 people for 2 days, while another one will actually run a full clinical trial with 60 diverse people running for a month. To assess how much you should trust such a claim from a brand, try to get the details on what tests they have done.

We do not recommend blindly following the comedogenic ingredient ratings. If your goal is to reduce clogged pores and acne, start by building a consistent simple fragrance-free skincare regimen that includes a sunscreen, gentle cleanser, a moisturizer, plus a few anti-acne actives like Retinoids, Niacinamide, Azelaic Acid, Salicylic Acid. It’s ok if some of the products you choose contain a few ingredients with high comedogenic rating: most likely, the comedogenic ingredients in them are very diluted and there will be no negative effects on your pores.

Be more careful with products that contain a single ingredient in high concentration: for example, oils, butters or balms.

If you have noticed a sudden increase in clogged pores and it comes after 2-3 weeks of starting a new skincare product (this is the time it takes for comedones to form), then it makes sense to check its ingredients for comedogenicity.

If you notice a sudden increase in inflamed spots, the cosmetics you use can be a trigger, but it would not be coming from pore clogging but from irritation.

Yes, it is possible, but the breakout is, most likely, an irritant reaction rather than acne. Acne takes 4-6 weeks to develop. If you’ve got inflamed spots within 2-3 days after using a cosmetic product, they’ve appeared because of an irritation, and not because the product clogged pores. If you experience a breakout like this, take a look at your full routine, not only the key “suspect” product. Over-exfoliating, over-cleansing, and using too many or too strong actives weakens the skin barrier and makes your skin more prone to irritations.