How does the drug detection window for hair compare to urine and oral fluid?
Drug detection times vary depending on the dose, sensitivity of the testing method used, preparation and route of administration, duration of use (acute or chronic), the matrix that is analyzed, the molecule or metabolite that is looked for, the pH and concentration of the matrix (urine, oral fluid), and variations in metabolic and renal clearance.2 In general, the detection time is longest in hair, followed by urine and oral fluid.2 Drugs in hair may be detectable for approximately 90 days, whereas drugs in urine are generally detectable for one to seven days or longer in chronic users and in oral fluid from five to 48 hours.2
