Drug detection times describe how long a drug, drug metabolite or alcohol-related marker may remain detectable in a biological specimen after use. Detection windows are estimates—not guarantees—and can differ significantly depending on the substance, specimen type, frequency and amount of use, individual metabolism and testing cutoff level.

This guide compares estimated detection windows for urine, saliva, blood and hair testing. It covers commonly screened substances such as THC, cocaine, amphetamines, methamphetamine, opioids, fentanyl, benzodiazepines, barbiturates, methadone, oxycodone, tramadol, K2 and EtG.

Urine testing is commonly used for recent and past substance-use screening because many drugs or their metabolites remain detectable in urine after their immediate effects have ended. Saliva and blood generally focus on more recent exposure, while hair testing may provide information about a longer historical period. No specimen type provides an exact time of use or automatically establishes impairment.

Actual detection times can be affected by dosage, frequency of use, metabolism, hydration, body composition, liver and kidney function, specimen collection time, test sensitivity and cutoff level. Rapid drug tests provide preliminary qualitative results. Any non-negative result should be confirmed using an appropriate laboratory method.

Before selecting a test, confirm that the device includes the required analytes and cutoff levels. You can compare our urine drug test cups, oral swab tests, CLIA-waived products and Forensic Use Only configurations using the links below.