The 8 Best Noncomedogenic Oils For Acne-Prone Skin, From Derms

While this term is pretty standard in the beauty industry right now, it's not without its flaws. Namely: Experts do not seem to agree on a standard practice for evaluating and classifying ingredients. There are "comedogenic scales" and lists, but each varies quite a bit, and none functions as an official tool used by dermatologists or cosmetic chemists. So what we have left is to sift through the research – or in some cases, anecdotal evidence – to find out which ingredients are more likely to cause clogged pores. Additionally, the term is not regulated by the FDA, so brands can use it as a marketing tool even if their formula could trigger breakouts (which arouses suspicion among consumers).

To understand how we got here, it is important to understand this story of the concept. The comedogenic scale (ranks 0 to 5) was first introduced in the 1970s by dermatologist Albert Kligman, M.D., who actually helped the pioneer of Retin-A. In it, the researchers used the rabbit ear model. For several reasons, that's enough to pause, says cosmetic chemist Krupa Koestline. The first is that rabbit ears are much more sensitive than human skin, and therefore what could cause acne in the animal might be fine for human use. The second reason is that no modern literature has been produced to confirm the effectiveness of this test.

After all, it's always worth noting that everyone is unique. We can make educated guesses about what might work for a particular skin type, but ultimately we can never know exactly how the skin reacts to something. "Even if two people are predisposed to acne, what is non-comedogenic to one person may be so to another," says state-certified dermatologist Mona Gohara, M.D. One of the main factors is skin sensitivity. People with easily irritable and acne-prone skin can be triggered by more products than people with just oily skin. But there are a whole host of other problems, including how easily your pores clog, how big the pores are, and how quickly your skin flakes on its own.