marijuana contains two drugs (along with the many other drugs) called cannabinol and cannabidiol. When you take these two drugs you're "telling" your liver to slow down and not metabolize drugs out of the body. Polyphenols in caffeinated tea (green, black, white, or oolong) overcome the inhibitors in cannabinol and cannabidiol. Drink some tea a few days a week, you'll help your liver matabolize drug metabolites in your body. All this and much more in a great book called Passing Drug Tests: The Gospel of Getting Clean for UA's. Written by Kenn A Biscranium.