I use dimethicone in my lotions all the time, especially in winter. It is a great ingredient to have if you have itchy, easily irritated skin like I do. It is a great barrier ingredient for the skin.
I don’t use it in my hair, but that’s because I have wavy curly hair and use the Curly Girl Method for my hair. The reason to avoid them when you have curly hair is because they coat your hair, rather than penetrate it. Curly hair is drier because its structure prevents the natural oils from your scalp from traveling down the hair shaft like it does with straight hair. So the theory is, if you put silicone products on your hair, you are preventing or reducing the amount of moisture you can get into your hair, which contributes to the dryness of your hair and makes it frizzy (or frizzier, since curly hair tends to be frizzy naturally). If you are straightening and/or blowdrying your hair, silicones are in products to help shield your hair from some of the damage done to it by the heat, I believe.
I don’t subscribe to the belief that silicones, synthetic or lab created ingredients are bad. I think you miss out on a lot of great ingredients if you do, but that’s my opinion and what works for me. Others are not comfortable using more synthetic ingredients, and if that works for them, I’m OK with that too. I just don’t let it stop me from trying or using them simply because others feel that they are bad. There is a lot of mis-information on the internet that is not scientifically sound. This creates a lot of fear in people, but that doesn’t make the information right or true. Find what works best for you is my philosophy.
