"Crystal speed" or "crystal met" is the well known drug Methamphetamine. The admission takes place usually nasal, in addition, intravenously and orally. A particularly pure form (recrystallized hydrochloride) is known under the name "Ice", which is taken up inhalationally by smoking (more intensive "kick" with shorter duration of effect).
The physiological effect exists in a suggestion of the circulation and acceleration of the pulse. Methamphetamin acts stimulating at the CNS and increases the efficiency, tiredness and sleep are reduced. For this reason it is used in sports also as a doping agent.
The craze potential is very large, apart from fast developing physical and psychological dependence it comes to abnormous psychological reactions, illusion conceptions and sudden incalculable ready for violence shank. The abuse can lead to irreparable organic and psychological damage. For this reason the use as therapeutic agent has been stopped.