Equisetum arvense, also known as horsetail, is an herbaceous perennial plant found in temperate climates in North America, as well as in similar climates in Europe and Asia. In spring, the stem of this plant resembles asparagus, which then withers and turns brown in early summer, giving way to stems that are thin and look like the tail of a horse.

Horsetail leaf extract is used in skin care products because it is a rich source of silicon. Silicon is a trace mineral that is important to nail, hair, bone, and skin health in humans. It is needed for synthesis of collagen and elastin, which are both proteins that help maintain the skin’s youthful appearance. It is believed that applying horsetail leaf extract to the skin provides the silicon needed to promote collagen and elastin synthesis, resulting in firmer and more elastic skin.

Horsetail leaf extract also contains phenolic antioxidant compounds. Antioxidants limit oxidative damage caused by free radicals, the unstable molecules that contribute to the formation of premature wrinkles and fine lines on the skin. Due to these properties, horsetail leaf extract is often used in anti-aging skin care products.