Ban Lan Gen (Isatis Root) is a Chinese herbal medicine anti-viral remedy. Taken when you feel the very first signs of a cold, the cold is less severe. You can also take a capsule a day to help prevent colds. This is a product I use all the time, since I work in a health clinic. I found it here cheaper and with free shipping. Didn't have to fight crowds, spend money on gas, or put wear and tear on the car. Better all the way around.