In the context of cannabis, a QP refers to a quarter pound, which is equivalent to 4 ounces or 113.4 grams. It can be a quarter pound of cannabis bud or shake. A QP is a large amount of cannabis and is commonly bought by frequent smokers, resellers, and people who need a lot of cannabis for medical purposes. It is one of the larger quantities of cannabis that can be purchased, with an eighth being the most common amount consumers purchase.