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Fatskn USA

Are comedogenic ratings reliable?

Are comedogenic ratings actually useful?

Long story short, no, comedogenic ratings are not reliable at all. But here's some background.

When I was first experimenting with making body butter for my pregnant belly and my baby-to-be, I was a bit concerned about the comedogenic rating of cacao butter : 4 (on a scale of 0 to 5). 

But the SMELL!

So I tried it anyways. Lo and behold, no issues. No breakouts on my face, on my back. Nothing. 

What is the comedogenic rating scale?

In the mid-1950s they developed the Rabbit Ear Assay to gauge how likely a certain ingredient is to cause comedones or skin irritation (aka how likely it is to clog pores and cause acne). They literally put the oil/butter on a rabbit ear and rate the reaction. Dermatologist James Fulton published the most extensive listing of products and their rating in the late '80s, all based on the Rabbit Ear Assay. While rabbit ears are much more sensitive than human skin, is this really the best indicator for how humans will react? 

The comedogenic rating is a scale of 0 - 5 : 0 means no irritation and 5 means plenty. Sometimes a product may say a range, which just indicates that the same ingredient from a different source could cause a slightly different result based on a variance in chemical makeup due to terroir, food, etc.

Many studies both on animals and humans have been conducted since and they have unanimously determined that such a scale is unreliable:

"Making assumptions about a finished product based on animal models of one ingredient proved to be unreliable. Multiple researchers studying the same ingredient even obtained differing test results. The link between the comedogenic potential of single ingredients and finished products was never established; many finished products containing ingredients identified as comedogenic did not instigate comedo formation."*

The dilution rate was also found to have an effect on how potentially “pore clogging” an ingredient could be. Many formulations made with higher-rated comedogenic ingredients often scored lower once combined. Very confusing.

But it's all over the internet!

All these sites and blog posts we see about the ratings of different ingredients...they're all just regurgitating faulty "evidence" from the 50s that has been debunked. It's the same thing as those pushing PUFAs as heart-healthy....

n = 1

So we've established there's no useful cheat sheet to know whether or not a certain product will make you break out. So the only thing left is for you to do it for yourself! Personally, I break out with coconut oil, avocado oil and castor oil. It all just feels too heavy. 

In this space, for the most part people seem to be less concerned about the comedogenic rating and more concerned with the PUFA/HUFA content, which is fantastic. I'd really like to think we're focusing on the right thing, finally...hopefully? 


Skin: an extension of your gut

It seems quite easy for us to accept the idea that different people react differently to different foods, so why shouldn't it be the same with skincare? That said, it still boggles my mind when people have issues with raw dairy, high quality eggs and grassfed/grassfed meat and if I'm being honest in my heart of hearts I believe tallow (and all animal products) is good (needed!) for everyone. Truly.

But I digress. 

It is absolutely possible that you may break out with a product that other people don't break out from. Is it a healing reaction? A histamine reaction? What is your body trying to tell you? All of this depends on the person. Where are you at with your skincare? With your diet? With your health? 

From what I've seen, Fatskn works well with all skin types - young, old, acne-prone, dry, and everything in-between. I did have one person tell me in passing at a market that whenever she puts tallow (not mine) on her face she gets red, but she moved on before I could ask her more questions as this was something I'd never heard of! Perhaps a histamine response? 

I am always keen for feedback - both good and bad. It's the only way I can continue to improve my product. Please never hesitate to reach out with questions via DM or email!

xo Caitlin

PMID: 29616616, 16488305

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