PCP, also known as angel dust or whack, is a shortened form of phenylcyclohexyl piperidine (the formal name for the drug called phencyclidine). It is a white crystalline powder which can be mixed into a drink, taken as a tablet, smoked or snorted. It is commonly added to cannabis to enhance its effects - this is sometimes called super grass or killer joint. PCP is an exceptionally dangerous drug as it causes drastic alterations in the user's perceptions of reality which can be very frightening as well as euphoric. It also gives a sense of detatchment from the real world which is dangerous in itself. Effects can last anywhere from a few minutes to eight hours and despite the negative nature of them PCP is extremely addictive. The most unsettling aspect of PCP use is that it can still cause intoxicating effects many years after a dose has been taken, due to the way the drug and its by-products are stored in fat and tissue within the body. Everyday stress or exercise in later life can cause a sudden relapse into a nightmarish PCP trip, normally when the person is least expecting it.