Silica is crucial for healthy bones, thick lustrous hair, and strong, flexible joints. But when it comes to supplemental silica, the form you take makes all the difference. Silica-20 provides 20 mg of silica (per serving) gently extracted from horsetail plant (Equisetum arvense) that is harvested at exactly the right time for optimum silica content. This source is one that your body easily and readily utilizes for noticeable benefits.