Oral fluid testing has the ability to detect drug use within the first few hours. This is a window of time that is omitted by urine test results. In some cases, it will return a positive result immediately after usage. This, with its ability to detect most drugs from 1 to 4 days after last use, makes it the best testing method for both impairment and post-accident testing. The early detection time is also very useful in dosage monitoring.
