There are many common foods that have varying degrees of toxicity. Oxalic Acid is a good example. I use mugwort has a smudge stick which works wonderfully for increased lucidity when dreaming. I wouldn't use mugwort in a tea but I do use sage tea for the same thing. I'm also careful not to use it day after day after day. When used responsibility I feel it's no more toxic for my liver than too much spinach or a green banana.