Silicones are synthesized in factories, and they're made by combining silicon (an element found in sand) with oxygen, hydrogen, carbon, and sometimes other materials. Silicones work by covering hair with a thin hydrophobic (waterproof) layer. This coating reduces the porosity of the hair.
What do silicones do?
In terms of the pros, you’d be hard-pressed to find a component that serves up as many immediate cosmetic benefits as silicones do - it’s no wonder that they’re one of hair care’s most prevalent ingredients. They can be found mostly in conditioners, but also in serums, oils and even shampoos. Their properties make them very good at doing several different jobs for a range of different hair types. In particular they can:
1) Absorb and retain moisture from the air (particularly good for dry hair)
2) Leave a lightweight coating on the hair (popular in smoothing and anti-frizz products)
3) Increase in size when heated up. Perfect for fine hair as it gets under the cuticle and then inflates to ‘puff’ it out and make it look thicker.
When hair is fully hydrated the cuticle is sealed, lies flat and light bounces off it so it gleams with a beautiful glossy glow. Silicones add another barrier layer to hair strands, so, yes, initially it looks shiny and new. However, silicones prevents moisture from penetrating the hair shaft, so hair becomes a magnet for dirt and other ingredients and over time hair accumulates more product build up. As a result tresses are weighed down and can become limp, lifeless and dull. Conditioners and nutrients are unable to penetrate the hair fiber, sit on the surface and in the worst case scenario the hair becomes brittle, frizzy and susceptible to breakage.
Silicones vary greatly in their performance and wash out capability. Water-soluble silicones are much kinder to your as they wash out easier and don’t leave a heavy build-up behind. Two ingredients to look out for are cyclomethicone, a very common silicone that leaves less build up on the hair and Dimethicone Copolyol, a more expensive silicone that’s lightweight and leaves minimal build up.
If you choose a product with non-water soluble silicone, you’ll definitely need to use a clarifying sulfate-based shampoo to remove it. Amodimethicone is very common in leave-in conditioners and can weigh the hair down. But it works well on thick, curly and afro hair. Dimethicone is the most common and cheapest silicone, but the hardest to remove.
What are alternatives to silicones? High-quality natural oils such as argan, almond and coconut that are loaded with antioxidants, linoleic acid and omega 6 fatty acids add spectacular shine and gloss. They come with a down side...no heat protection, in fact they can burn your hair if exposed to high heat.