Why use silicon. Except for baby products in the supermarket, almost all shampoos contain silicone oil. Why add silicone oil to shampoo? Does silicone oil block hair follicles and damage hair? Silicone oil is sticky and malleable and has a moisturizing and softening effect on hair. Hair grows from hair follicles in the scalp. The main component is keratin. There are many uneven scales on each hair. When the hair scales are damaged, they will lift up, which will increase the friction between the hairs, causing the hair to be tangled together. More friction will aggravate the damage of the hair scales. When you wash your hair, the silicone oil in the shampoo adheres to the gaps in the hair scales, so that the surface of the hair is flattened, and the hair will feel soft to the touch. The purpose of washing hair is to get rid of dust on the hair and scalp, and to wash away more oil. However, when washing hair, the hair absorbs water, swells, becomes moist and soft, and the protective oils on the outer skin are also washed away.