Urine drug screen

A urine drug screen is a laboratory test on a urine sample that detects metabolites, the compounds the body produces after processing a substance, rather than the substance itself.

It is the most common format for workplace and pre-employment testing because collection is simple and metabolites persist in urine longer than parent drugs remain in blood. A standard panel screens for several drug classes by immunoassay, and any non-negative result is sent for confirmation by mass spectrometry. The sample is also checked for dilution or tampering.

For cannabis, the panel looks for THC-COOH, the metabolite of delta-9 THC; CBD is not on a standard panel and its metabolites are not what the test is designed to find. The result reflects exposure over a period of days to weeks, depending on frequency and individual factors, and cannot show when exposure occurred or whether impairment is present. A product's composition does not determine how a specific program will handle a result.