Silica is a naturally occurring non-metallic element, also known as silicon. It is a component of certain bodily polysaccharide structures such as hair, skin, and nails. NOW Silica is derived from Horsetail Extract and is thoroughly screened for potency and purity. We have complexed the silica in this supplement with other synergistic ingredients for a truly effective dietary supplement. Silica helps maintain healthy hair, skin and nails. It also promotes calcium absorption in the early stages of bone formation.