It is said the perfect related tea is the Se from root just 0.03-40 mg/kg inside. And, 1 bag or 2 bag, 3g or 6 g, a day is safe and balance the lack of Se from food everyday to low down the rate of cancer in physical body. However the research related is not enough in papers. But this tea is real delicious indeed. So, 60 bags in one mail for 1 or 2 month is real a kind of enjoy of life.