Horsetail should be used with special care. Before using horsetail (Equisetum arvense) one should conduct research on how to use the plant safely. People with various health conditions (heart conditions, blood circulation conditions and more) should not use horsetail at all.
Horsetail should not be used for a prolonged amount of time. Horsetail contains nicotine and an anti-nutrient which reduces the amount of potassium in the body and the amount of vitamin B1.
Horsetail has many more potential side effects, and therefore one should research before using it.
There are other plants with a high silica content such as oatstraw and bamboo.