I know a lot of herbs are grown in China and for centuries they were ahead of the world on how to properly use herbs for good health. There is one company that produces some good quality chinese herb combo's == they are very expensive... another company has knockoffs of the good quality chinese herbs ... but I digress, horsetail isn't a Chinese herb, just got me to thinking about them...
People around the world have been using herbs to treat illnesses for millenia. The difference is that the West dropped the tradition once it came up with medical treatments based on the scientific method. The Chinese still have this fetish because it - along with having the world's longest recorded history diary and largest population - is one of China's few claims to fame in a world where 99% of what Chinese see on a day-to-day basis is a Western invention or design. In other words, many Chinese would rather cling to Chinese quackery and racial pride and die than adopt Western medication and live.