Understanding Comedogenicity in Skincare:
What You Need to Know Before You Break Out
Today, we’re diving deep into comedogenicity—how specific ingredients in your skincare products might be triggering breakouts. So, get comfy and let’s clear up some myths and confusion around this topic.
What is Comedogenicity?
Comedogenicity refers to the tendency of an ingredient or product to clog pores. Ingredients are typically ranked on a scale:
- 0 means completely non-comedogenic.
- 1 indicates slight comedogenicity.
- 2 to 3 means moderately comedogenic.
- 4 to 5 suggests it is highly comedogenic and very likely to cause breakouts.
These ratings stem from scientific studies published in reputable journals. While this lends them credibility, it’s essential to dig deeper to see if they hold up in real-world conditions.
Problems with Comedogenicity Scales
Tests Aren’t Done in Real-world Conditions
Ideally, every product would be tested on every individual’s skin to create a definitive list of what will and won’t cause breakouts. However, this is impractical due to the variety and volume of products, along with the diverse range of skin types. Instead, researchers use simplified models, which often fail to capture the complexities of real-world usage, leading to potential inaccuracies.
The Most Common Rabbit Ear Test Is Flawed
One commonly used model is the rabbit ear test, where substances are applied to the inner ear of a rabbit. Rabbits’ ears are more sensitive than human skin, leading to quicker reactions, including numerous false positives. For instance, petroleum jelly (the sole ingredient in Vaseline) was once considered comedogenic, a myth debunked years later. Even Dr. Kligman, who pioneered this model, acknowledged its limitations for predicting human skin reactions.
The Debate on Petroleum Jelly
Petroleum jelly, or petrolatum, is a polarizing ingredient. Initially flagged as comedogenic based on rabbit ear tests, subsequent studies revealed its non-comedogenic nature on human skin. This discrepancy highlights the importance of context and real-world application when interpreting these studies.
Limitations of Human Skin Tests
Human skin tests often use the back as a testing site, which differs from facial skin significantly. Back skin varies in terms of oil production and exposure to environmental factors like sunlight, which means results may not translate well to facial skin. Moreover, these tests typically involve small sample sizes and non-representative conditions, like covering the skin with bandages, which can enhance ingredient penetration and increase the likelihood of pimples.
Comedogenic Ingredients Don’t Always Make Comedogenic Products
An ingredient deemed comedogenic in isolation might not trigger breakouts when diluted in a formulated product. Skincare products generally contain a mix of ingredients at low concentrations. For example, pure acetylated lanolin alcohol can be highly comedogenic, but when diluted, its effect significantly diminishes. Consequently, simple charts listing ingredient comedogenicity can’t reliably predict a product’s potential to cause acne.
When Are Comedogenicity Scales Useful?
Narrowing Down a Breakout Cause
If you’re breaking out and can’t pinpoint the culprit, checking for highly comedogenic ingredients is a good starting point. Ingredients rated 4-5 high on an ingredients list are more likely to be the cause, providing a useful direction for your investigation.
Avoiding Large Amounts of Comedogenic Ingredients
For acne-prone skin, avoiding products with high concentrations of known comedogenic ingredients is prudent. If you’re using a product that has worked well, don’t stop just because it contains ingredients flagged as comedogenic. Real-world results matter more than theoretical risks.
Avoiding Undiluted Comedogenic Ingredients
Certain natural oils and butters, often used undiluted, make comedogenicity scales particularly useful. Coconut oil, for example, is rated high on the scale but used without problems by many. If your skin tends to break out, consider starting with a patch test or opting for milder alternatives first.
What to Avoid Doing with Comedogenicity Ratings
- Don’t discard products solely because they contain comedogenic ingredients.
- Don’t avoid potentially beneficial products just because they include a few comedogenic ingredients.
- Don’t stress about ingredients beyond the first five on a list; they’re usually too dilute to pose significant risks.
- Don’t use these ratings as a substitute for patch testing; even non-comedogenic products can cause individual reactions.
Debunking Myths and Exploring Controversies
The Myth of Universal Comedogenicity
It’s a common misconception that a flagged ingredient will cause breakouts for everyone. Skin chemistry varies significantly from person to person, influenced by factors such as bacterial flora, lifestyle, and environmental conditions. This variability means one person’s breakout trigger might be another’s holy grail ingredient.
Genetic Factors in Comedogenic Responses
Genetics also play a crucial role in how your skin responds to ingredients. Some people are genetically predisposed to acne, meaning their skin is more reactive to certain substances irrespective of comedogenicity scales. Understanding your skin’s unique needs and reactions is essential for making informed skincare choices.
In summary, while comedogenicity scales can be useful, they are far from definitive. Your skin’s unique chemistry plays a significant role. Real-world testing on your skin is the best way to assess a product’s suitability.
I hope this breakdown helps you navigate the complex world of comedogenic ingredients. If you enjoyed this and want more skincare science, give this post a thumbs-up and subscribe to my channel. For additional insights, follow me on Instagram and check out my blog. Let me know in the comments what other topics you’d like me to cover. See you next time for more DIY skincare science!
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