<human>: Is there a way to tell if someone has been using methamphetamine?
<bot>: Yes, there are several ways to test for the presence of methamphetamines in urine. One method is to use an enzyme-linked immunosorbent assay (ELISA). This involves testing a sample of urine with antibodies that bind specifically to the drug. Another technique is to use gas chromatography/mass spectrometry (GC/MS), which separates and identifies compounds based on their mass-to-charge ratio.