The results from a urine test can take from a few days to a week for a positive screen, while negative results are usually found in a single day. Additionally, if a rapid test is requested, the results are received on the same day.
Some drugs are detectable in urine from a couple days to three or four weeks with chronic use, such as marijuana. To reduce the chances of a false-positive, provide an up-to-date history of all prescription, over-the-counter and herbal drug use prior to taking the urine test. If a positive result is received, some labs have the option to pay for a retest of the original urine sample. A new sample is not permissible.