Grapefruit Juice (GFJ)- I'd toyed with the thought of making use of grapefruit juice for some time but have read through blended reports. Just lately I read that it won't inhibit CYP2D6 but rahter 3A4 which is answerable for conversion of codeine into norcodeine. In theory by inhibiting 3A4 you leave much more codeine for 2D6 to become morphine. So