While most health and wellness enthusiasts focus on their internal health, its easy to forget hair, skin and nail health, which can get a big boost from a horsetail supplement. What is horsetail extract? Horsetail is a traditional supplement derived from a cousin of the fern plant thats been used throughout the ages, dating back to ancient Greece. Horsetail contains silica, an important mineral that promotes hair skin and nail health by encouraging calcium absorption into the body. a horsetail herbal supplement can help thicken and strengthen hair and nails while supporting bone health too. So keep your hair, skin and nails looking and feeling great while boosting your bone health and outer glow with Swanson Full Spectrum Horsetail silica. Found more commonly in plant-based foods than dairy or meats, silica is essential to a healthy diet, which makes taking a silica supplement such as horsetail important for optimal wellness.