Horsetail provides natural silica, a mineral that supports healthy hair, skin, and nails. Many people also take it for bone and joint health. The aerial parts of the plant are steeped as a tea or swallowed in capsules, usually with food.
Thiaminase in the herb can break down vitamin B1, so long-term use may lower thiamine levels. Do not take horsetail if you have kidney disease, are pregnant, or are breastfeeding.
Talk to a doctor before using horsetail with diuretics, lithium, or blood-thinning drugs. A healthcare professional can check for interactions.