Quest Diagnostics’ By the Numbers series recently took a closer look at the numbers, facts and data that impact workplace drug testing programs, examining how long drugs can be detected using a drug test. This “drug detection window” or “detection time frame” can vary, depending on the specific drug, usage patterns, individual biological variability and cutoff. The study provided general guidelines for the detection windows of the most trusted workplace drug testing specimen types. Urine detects recent or new drug use, while oral fluid reveals drug use in the previous 24 to 48 hours (or 24 to 36 hours for THC). Hair testing provides a detection window of as far back as 90 days.