After taking methamphetamine (commonly known as meth), the metabolism and discharge time of drugs in the body vary from person to person and are affected by a variety of factors, including the individual's metabolic rate, frequency of use, dose, weight, age, liver function, etc. However, in general, the detection window period of methamphetamine in urine is as follows： -**Single use**: The time when methamphetamine or its metabolites (such as amphetamine) can usually be detected in urine is **1 to 4 days**. -**Long-term or frequent use**: For people who use methamphetamine for a long time or frequently, the window for urine testing may be extended to **5 to 7 days**, or even longer in some cases. ### Detection method Ordinary drug urine tests usually use immunoassays (such as ELISA) to detect methamphetamine and its metabolites. If the preliminary test result is positive, it will usually be confirmed by more precise methods (such as gas chromatography-mass spectrometry, GC-MS). ### Other influencing factors -**Hydration status**: Drinking a lot of water may dilute the concentration of drugs in the urine, but it usually does not significantly shorten the detection window. -**Drug metabolic rate**: Individual differences may cause some people to metabolize and expel drugs faster or slower. ### Precautions -The accuracy of drug urine testing is affected by a variety of factors, including testing methods, sample handling, etc. -Long-term use of methamphetamine may lead to severe physical and psychological dependence and health problems. It is recommended to seek professional help to quit. In short, methamphetamine is usually detectable in urine for 1 to 7 days, the specific time varies from person to person.