Question: Why are behentrimonium methosulfate and cetearyl written together?

Angel wrote to me to ask: Why are behentrimonium methosulfate and cetearyl alcohol often written together as though they are a compound solution?  I understand your explanation of why the cetearyl alcohol is used with the behentrimonium methosulfate in hair conditioners.  But is there a reason why I’ve found the two written together as one compound in almost every definition of behentrimonium methosulfate or explanation of what this single product is? What is all the hoopla about concerning behentrimonium methosulfate in the “natural” community? Isn’t this a synthetic?

A note before I get to the question...I don't discriminate between what I call minimally processed ingredients - those that are closer to how we find them in nature, like oils, butters, or hydrosols - and those I think of as being more processed - like fatty alcohols, fatty acids, esters, preservatives and so on. I don't think any of our ingredients are straight from nature; everything is processed in some way. We don't use olives, we use olive oil. We aren't using salt directly off the shores of the Dead Sea - they're cleaned before we see them. Clay, mud, hydrosols, essential oils - every last one of these ingredients is processed in some way before we can use them in our products. Synthetic ingredients would be those made in the lab, like cyclomethicone or some of the cationic polymers, for example.

If you really want to mess with your conception of natural vs. synthetic, read this article about the poor little mineral oil molecule. I feel a bit like that Ikea guy - do you feel sorry for this molecule? (Click here for that great Ikea ad! And people wonder why I'm a bit hoarder-ish?)

So why BTMS and cetearyl alcohol are always written together? Behentrimonium methosulfate is an ingredient that can stand on its own, but it's generally found with a fatty alcohol. This would be what we call a compound (specifically a cationic quaternary compound). You'll find BTMS-25 or BTMS-50 or other types of BTMS or BTM as product names, and it could be the writer is referring to the compound instead of the ingredient. I don't think you can buy behentrimonium methosulfate on its own - we always find it with a fatty alcohol, regardless of manufacturer - so this is why you see it referred to in this way.

The reason you find behentrimonium methosulfate paired with a fatty alcohol, often cetearyl alcohol but sometimes cetyl alcohol? Because fatty alcohols work to boost the substantivity of cationic quaternary compounds, making them more conditioning and moisturizing (click here for more information).

There is no way I would consider something like behentrimonium methosulfate as being even remotely close to minimally processed, and I wouldn't consider cetearyl alcohol, cetyl alcohol, and the other fatty alcohols minimally processed. Anyone who considers these things as natural is fooling themselves. The problem is that you can't make a natural conditioner and people really want to make a natural conditioner. So instead of accepting that they can't make a natural conditioner, they stretch the definition of natural to include anything they want to use.

If you want natural, then accept there are ingredients you won't be using. Don't twist the definition so you can get what you want. When you see the phrase "derived from" ask yourself why is this ingredient listed in this way? We don't write olive oil (derived from olives) but you will see cyclomethicone (derived from sand) or sodium coco-sulfate (derived from coconuts), for example. These last two ingredients are heavily processed to become what they are, and the phrase "derived from" is generally used as a weasel word to hide something that's not really natural but the manufacturer would like you to believe might be. Behentrimonium methosulfate may be derived from Colza seeds, but everything is derived from something - that doesn't make it natural!