What is Dimethicone?

Daniel Judd BSc MBiol


What is Dimethicone?

Dimethicone is an oil found in many moisturising skin care products. Unlike a lot of other oils used in skin care, dimethicone is silicone based and needs to be made chemically as opposed to extracted from natural sources. While it’s different in that regard, dimethicone still does a lot of the same things as other oil based cosmetic ingredients. It’s a popular ingredient in moisturisers because it works as an emollient, that is, it soothes and softens the skin.

Dimethicone is sometimes added to other skin care products to give them a moisturising ability. It is also found in hair products like conditioners and anti-tangle products.

Outside of skin care, dimethicone is sometimes added to cooking oils in small amounts to stop the oil from spitting everywhere.


How does it work?

Your skin becomes dry when water escapes from its surface as water vapour. Your skin has a natural barrier on the surface made of oils which repel water, keeping it trapped inside. This barrier can be worn down by things like hot showers and strong soaps. Emollients like dimethicone sit on the skin and top up the natural oil barrier, trapping water inside your skin and keeping it moisturised.

In liquid products, dimethicone also works as an anti-foamer, preventing bubbles from forming on top of the product making it hard to use.

In hair conditioners, dimethicone creates a similar protective oil barrier around your hairs which also gives your hair a shiny and glossy look.


Side effects:

Dimethicone is a well-tolerated ingredient and doesn’t usually trigger any adverse reactions. It is possible to be sensitive to dimethicone and experience redness and swelling when using it. It’s also possible for some people’s skin to actually feel drier after use, despite the intended moisturising effect.

As dimethicone is an oil, oily skin can be made worse by adding dimethicone on top of the already present oil.

Interactions with other medicine:

No drug interactions have been reported with dimethicone.


Other names for Dimethicone:

Dimethicone Copolyol; Dimethyl Silicone; Highly Polymerized Methyl Polysiloxane; Methyl Polysiloxane; Silicone L-45; Dc 1664; Dimethicone 350; Dimeticone; Dow Corning 1664; Mirasil Dm 20; Viscasil 5m