What foods contain THC?

A urinary drug screen or a blood test would screen for a substance called tetrahydrocannabinol or THC. THC is the psychoactive ingredient in marijuana and it can take about a week to be fully excreted from the body. There is no food that I am aware of that would cause THC to be found on a drug test as THC is found only in cannibis plants. Unless of course you have been eating hashish cookies.

Actually, I did an experiment for this in school years back, & sesame seeds (You need >1 lb of them) can cause trace amounts to show up on a drug screen.

Poppy seeds make you fail for opiates.