Well cyrstal meth also called as methamphatamine has a half life of upto 9-15 hours. Half life is defined as the time in which half of the drug has been eliminated from our body and thus doubling the half life would be indicative of the time by which the drug would be completly out of your system. For methamphatamine the total time it would be out of your system should be approximately 18-30hrs.
This is the amount of time the drug would be out of your blood. However there are certain metabolites of methamphatamine which can be detected in the urine for upto 2-3 days.
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