Urine Drug Testing
A urine drug test usually can detect drug usage up to 3-4 days prior to the day of testing. If drug usage is frequent and heavy, it can often detect up to 7 days prior to the day of testing. Some drug substances like Benzodiazepines can be detected up to more than 7 days of usage as well. Mostly, the drug metabolites take about a week to completely go out of the regular bodily system, that is why a urine test is said to show positive up to 7 days after drug usage.
Usually, candidates find this method of drug testing easy to cheat on. Sample substitution and adulteration is often seen to get a negative result on the test. Additionally, drinking sufficient water and detox drinks are often found to help in passing this test as well.