How does a saliva drug test work?

Yes actually some employers are using mouth swabs for drug testing (Example Krogers) A saliva test, blood test or a urine test can be done Someone has been watching too much "Law and Order"! Just kidding! A saliva swab can be used to cross check DNA, but a test like that is VERY expensive. For a regular drug test, they generally use urine. If a urine spec doesn't do it, then they can draw blood and check that way. HOPE THIS HELPS <> Yes saliva test are less expensive than a urine or blood (not done very often) Hair is expensive also. Saliva is less invasive and can be done anywhere its like a taffy its very reliable and very hard to beat..they say its unbeatable..more and more people are using this test. States use it for probation instaed of urine inost states. So that says something. most drugs except pot stay from 2-7 days not 2-5 pot longer. BEST ANSWER DUE TO HAVING THEM DONE OFTEN