Dimethicone

If your skin or hair has ever felt instantly smoother after a product, there’s a good chance dimethicone was doing the heavy lifting. It’s one of the most used silicones in cosmetics for a reason: it gives that silky, cushioned, “my skin but better” finish without feeling greasy. It comes in lots of forms and viscosities, including lighter dimethicone oils and more textured versions such as dimethicone crosspolymer, which helps create that plush, blurring feel in primers and creams.

On skin, dimethicone acts mainly as an occlusive and skin-protective film former. That means it helps slow down water loss, so your face feels softer and looks a bit more polished. In one classic study on very dry hands, a dimethicone-based barrier cream improved roughness and dryness after repeated use over 1–2 weeks, which is why it turns up in some of the best dimethicone moisturizers, best dimethicone creams, and even a lot of “gentle for sensitive skin” formulas. It’s also commonly used in scar gels because it can help flatten and soften the look of scars over time by reducing water loss and keeping the area flexible. If you’re searching for the best dimethicone primer, this is the ingredient behind that soft-focus, pore-blurring finish people love on the face.

For hair, dimethicone is the classic slip-and-shine ingredient. It coats the hair shaft, reduces friction, helps with detangling, and can make hair look smoother and less frizzy. That’s why it’s so popular in conditioners, serums, and styling products, and why people hunting for the best dimethicone conditioner or best dimethicone hair products often end up with softer-feeling strands. Studies on silicone conditioners have shown reduced combing force and less breakage compared with non-conditioning shampoos, especially in damaged hair. The trade-off is that, because dimethicone is non-volatile, it can build up a bit on some hair types if cleansing is too gentle. So the best dimethicone shampoo is usually one that cleans well enough for your hair type, and the best dimethicone free shampoo is simply a preference thing, not a moral victory.

You may also see dimethicone in lice treatments, where it works in a very different way: it physically coats and immobilizes lice rather than acting like a traditional insecticide. Clinical trials have found certain dimethicone-based lice lotions can be effective after one or two applications, which is why people search for dimethicone for lice and the best dimethicone lice treatment. As for how to use dimethicone, the short version is: just apply the product it’s in, because dimethicone is rarely sold as a stand-alone active. It shows up in dimethicone lotion, dimethicone cream, even some dimethicone tablet search results from confused internet corners, but in cosmetics its job is simple: make things feel smoother, look better, and behave a little more nicely on your skin and hair.

Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.

As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity. 

As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash outand might cause some build-up (btw, this is not true to all silicones, only the non-volatile types).