Glass smoking pipes are typically used for smoking illegal drugs. These include marijuana, crack cocaine, crystal methamphetamine, phencyclidine (also known as PCP or "angel dust"), opium and dimethyltryptamine (usually referred to as DMT).
Glass pipes intended for smoking marijuana are often colorful and intricately designed. Plain pipes with a bulb at one end are most commonly used for smoking crystal methamphetamine. Straight glass pipes are typically connected to the use of crack cocaine. Crack users sometimes have burned fingers or lips from holding the pipe while it heats up. Other types of drugs are generally smoked from the same colorful pipes used to smoke marijuana.