Hello, Welcome to Just Answer and thanks for your question. Methamphetamine is detectable for 2-4 days after the last use for someone who uses it frequently. For a one-time use, it is detectable for up to 7-8 hours. How long it is detectable depends on age, sex, weight, metabolism, and how much and how often one uses it. There is really no way to speed up the metabolism so that it is detected for any shorter period of time.