Horsetail, Equisetum arvense, is rich in the mineral silica, which is used along with calcium to form bones, nails, hair, and skin. Silica adds elasticity to tissues, making them strong but not brittle. It is astringent and is useful for internal bleeding, such as blood in the urine. It has a mild diuretic effect.
Excessive consumption may lead to a thiamine deficiency. The powdered herb is not recommended for children, but the tea is okay.
This can be taken as an infusion or tincture.