is there any risk of toxic levels of DNP being created if someone were taking grapefruit juice at the same time or is DNP broken down by a different enzyme.
I might be totally wrong, but I think DNP is excreted unmetabolised, so the liver does not do anything with it. It is probably just filtered out by the kidneys as is. So if that is true then grapefruit juice would not influence the half-life of DNP.