be careful to properly identify the leaves of the dandelion, if you are taking it from the ground (some weeds look similar, and some are poisonous). also, do not use those that have recently been sprayed with weed poison. dandelions seem to work on my kidneys alot. the health food store charges alot for the roots, but it's free in anyone's backyard. try not to break off the plant when removing, (the root is like a taproot, straight down), and clean well before use.