How long will it take to confirm a positive result?
Even though the initial screening test is 99% effective, no drug test should be considered positive until the confirmation test is done. Confirmation by Gas Chromatography Mass Spectrometry may take 24-48 hours from the time the specimen is received. Additional time may be required if you use a Medical Review Officer (MRO) to talk to the employee about their positive drug test result before a drug test is verified as positive.
