Ever wondered why some skin and hair care products feel smooth, velvety, almost slippery? And when you apply the skin care product to your face it’s almost as if you’ve used a Photoshop filter and the fine lines have been smoothed out.
The ingredient that has this effect is dimethicone. But when you do a quick search on the internet you find all kinds of information: From it’s bad because it causes acne or even worse is linked to hormone disruption or other long-term health issues. You’ll also find some people who swear by it because they love the velvety texture while others can’t stand it.
Of course, having a villain makes a good (marketing) story – and the beauty industry also loves a villain. So brands have started advertising products as silicone-free as a boasting and selling point. Even with this much controversy, dimethicone is often used. Just scan the ingredient list of your hair, skin, or personal care products.
Even if you avoid it like a pest for all your beauty products, you can’t escape it as it’s used as a food additive as well.
So, what is dimethicone?
Dimethicone or polydimethylsiloxane (PDMS) is a silicon-based polymer. This silicon oil is just one of the many kinds of silicons used in beauty. Silicone is derived from silica (sand is a silica).
It’s an emulsifier, that is it keeps other ingredients from separating. It’s also an emollient.
It’s considered an inert (this means it’s chemically inactive) and non-toxic synthetic ingredient, even though it’s man-made. It’s a cheap ingredient, so it’s often used in all kinds of products such as
- Moisturisers
- Cleansers
- Body washes
- Self-tanning products
- Shampoos
- Conditioners
- Hair dyes
- Primers
- Foundations
- Diaper rash creams
Why Is Dimethicone Used in Beauty Products?
Silicones have been used and researched since the 1950s. The US FDA has classed dimethicone as safe to use for personal care products and it is generally considered to be safe to use.
In beauty products, dimethicone creates a fluid and velvety texture. It gives the product a great deal of slip so that the product lied on. It also acts as an emollient – a barrier on your skin and seals in moisture by filling the spaces between the cracks in the skin. This is what improves the softness of your skin.
Even though its molecules are too large for the skin and hair to absorb, dimethicone forms a barrier that is at the same time porous and resistant to air. This breathable barrier protects against transdermal waterless without feeling heavy.
What does it do in a skin care product?
It is light, oil-free and non-comedogenic and its large molecules help temporarily fill in fine lines and wrinkles. As it makes the texture of the product uniformly smooth and fluid it’s a popular ingredient for oil-free moisturisers. It has other interesting properties:
- It’s hypoallergenic, non-irritating and non-comedogenic
- As an emollient, it’s a good moisturiser, keeping the skin hydrated by providing a layer of protection, which in turn also protects your skin from wind and chafing
- It improves the penetration of active ingredients and protects them from degrading before you apply them
- In sunscreen, it waterproofing and so helps it stay on
What does it do in make-up?
- The slip it gives helps the make-up glide onto your skin
- Just as with skin care products, dimethicone fills in lines and pores, making skin look plumper with fewer wrinkles. So, it’s often used in primers to make your skin into a smooth canvas for make-up
- It has a mattifying effect so that it can blur light, making skin look airbrushed
- It can make foundations and lipstick long-wearing but still keeping them flexible enough not to crack
What does it do in hair care products?
- Add shine
- Smooth out and detangle hair
- Help hair dye stay on longer
Is it vegan?
Dimethicone is made in a lab and so, doesn’t contain any animal products. So, yes, it’s vegan.
So, why the bad rep?
Well, it’s true that dimethicone forms a protective barrier on your skin. But it’s non-comedogenic and non-acnegenic. So, if you’re prone to oily skin or have acne, you’re probably already using oil-free formulas. And these contain dimethicone to o provide long-lasting moisture without clogging pores and causing breakouts.
But with this logic, when an ingredient forms a protective layer, then you’d also have to dismiss any other product that promises the same. Also, any product that you apply to your skin that blocks your pores has the potential to cause acne.
It’s often used in place of more natural ingredients like plant oils or butters. But it doesn’t mean natural is always better than synthetic (or vice versa). Natural oils can just as well clog pores just like synthetic products.
Something that can happen with virtually every product ingredient, so it’s always best to patch test before use.
What are the other silicones?
In addition to dimethicone, there are other types of silicone, such as phenyl trimethicone, cyclopentasiloxane, and PEG-10 dimethicone that are used in the beauty industry.
In general, silicones are used to improve the texture of the product. There are there major types of silicones that are used in cosmetic and skincare products.
You can identify most silicones by looking at the end of their name. If an ingredient ends in -cone, -siloxane or -conol, then it is likely a silicone.
Small silicones
They tend to be liquid and are volatile, that is, evaporate quickly from the skin or hair. Examples are phenyl trimethicone, cyclopentasiloxane.
Silicone polymers
These are long-chain molecules and can be either liquid or solid. Dimethicone belongs into this category.
Functional silicones
These contain other atoms that give them more properties on top of the usual silicone properties. An example is dimethiconol.
How to use it
Chances are, you’re already using it, considering how widely used dimethicone is. Key is to layer a product with it on top of your active ingredients, like retinoids or antioxidants. Then you have a protective layer sealing in the actives as well as moisture.
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