You may be surprised to find silicones in multiple hair products such as heat protectants, serums, conditioners, shampoos, hair oils, hair treatments, styling products and even cosmetics, lotions and sun- block creams.  Silicones are substances that are made only by chemical synthesis; they are not found in nature and are inorganic polymers with siloxane bonds holding silicon and oxygen together in their molecular structure (derived from petrochemicals). 

Hair products frequently contain silicones to give your hair a glossy and silky finish.  The problem is that, although silicones may temporarily give your hair this healthy appearance, they actually form a barrier around each individual hair strand.  Although this barrier may seem protective, over time it causes dryness because it keeps nutrients and moisture out.  This can eventually result in problems including split ends, brittleness, and a general lack of luster. On the scalp, it clogs the pores leading to an oily, itchy or flaky scalp and may cause thining hair, especially if you suffer from eczema or skin sensitivities.  A clean and residue-free scalp is crucial for healthy hair, providing a favorable environment for hair growth.  

Color-saving shampoos and conditioners frequently contain silicones to help shield color-treated hair by forming a barrier that slows down the rate at which color fades.  But buildup can also hinder color absorption when it comes to coloring your hair.  As a side note, not all silicones create a buildup on the hair.  There are typically 3 types of silicones: evaporating silicones, water-insoluble and water-soluble silicones.    If you have curly hair, water-insoluble silicones should be avoided as it leads to dryness and a loss of definition, with fine or thin hair silicones are more likely to weigh it down.

Although there are many different views on how silicones influence hair thinning or loss, it's crucial to consider the long-term effects of regularly using hair products that contain harmful ingredients like silicones.