Silicones In Shampoo, Conditioner & Hair Care: Bad For Hair Health Or Overreaction?

One area of hair care drums up a lot of debate: silicones. They're found in, well, a lot of products. Unless a product is 100% natural oils or specifically claims it is "silicone-free," it likely has some variation of silicones. (And even then, it might include silicone derivatives.) So why does all the controversy start bubbling up the second you drop the "S" word around hair care and even skin care fanatics? The answer takes some explaining, so allow us. 

Here are a few common names: dimethicone, amodimethicone, cyclomethicone, methicone, trimethicone, nylon, trimethylsilylamodimethicone, dimethiconol, bis-PEG-18 methyl ether dimethyl silane.

The short answer: They are cheap, effective, and make hair appear shiny and frizz-free. Formulating hair care products with oils and nutrients to achieve the same slip and sheen is time- and cost-consuming. Not to mention, they do provide pretty appealing aesthetic benefits in the short term: Shiny, frizz-free, softer hair is a hard thing to turn away. 

The answer is, like many areas of beauty, it's complicated. But there are some key points we can boil down to make it a little more digestible. 

There are valid reasons to choose to stop using silicones, many outlined here, but much of the confusion around silicones arises when they are conflated with "dangerous toxins and chemicals"—silicones just don't reach that bar. 

"They are the extra filler that help a product feel more luxurious," says Gabriel. Compare it to using a natural hair oil that uses ingredients like vitamin E, jojoba, or argan: These also make your hair shiny, tame frizz, and improve manageability, but they do so by feeding the hair antioxidants, fatty acids, amino acids, minerals, and the like. So you are getting the aesthetic benefit while also improving the quality of your hair. 

So if you use a leave-in conditioner with silicones then go to wash it with a shampoo that contains silicones, and then condition with silicones, that routine is likely causing quite a bit of silicone layering and buildup on the scalp and strand. So even if these individual products contain good-for-hair ingredients, those nutrients may not be able to penetrate the shaft because of the occlusive silicone coating. 

"The obvious drawback of all this is that you end up with hair that gets weighed down or greasy, so you are more likely to shampoo and style more often. This perpetuates what we call the cycle of damage. The more you wash and style, the more damaged your hair is, so the more you will feel like you need to reach for a silicone to get that soft feeling again. It's a vicious cycle," says McLaughlin. If you need guidance on how often you should actually be washing your hair, read our guide to shampooing.

Now, the beauty industry causes a lot of waste—that's no secret—and many eco-issues certainly trump the potential bioaccumulation of silicones. (Plastic waste and water consumption, for example!) But it's certainly part of the bigger picture. 

Those who avoid silicones avoid them largely in part because they avoid another type of ingredient: sulfates. Sulfates, as you may know, are a strong, foaming surfactant used in many shampoos and washes. Sulfate-free shampoos, which have come a long way in recent years, are at their core a more gentle wash. This is a good thing, as it doesn't disrupt our microbiome, harm our skin barrier function, or strip away our natural oils. However, it also means it's not necessarily as effective at lifting up the buildup caused by silicones. 

Remember how we previously noted that not all silicones are bad? Well, that's because researchers were able to develop water-soluble silicones that are generally fine in hair care, as they are easier to remove, aren't as sticky of an occlusive, and don't bioaccumulate. Look for dimethicone copolyol or any dimethicone with a PEG prefix, like PEG-8 (or higher) dimethicone.

That being said, here are skin-specific recommendations:

While silicones are safe for human use, they don't necessarily add benefit to your overall health. They exist to provide aesthetic improvements in the short run but cause buildup and overwashing in the long term due to their occlusive nature. They also may contribute to bioaccumulation in our water supply, which may be enough of a reason to nix overuse. All in all, there are valid reasons some may choose to avoid them in hair care—the most important thing is that you are informed about what they do and don't do.