I was just wondering how long it usually takes for heroin to be out of your system. My friend did a fairly small ammount (4 bags) last night and he might have a test Friday morning. This would give him well over 72 hours of cleaness before the test, but is that usually enough for H? I know for Oxy it would probably be out by then but oxy has a different curve...I was also wondering if someone stored urine before using the drug, and then gave in that urine a few days later, would it be possible for them to detect that the urine was old? There is no temperature strip on the cup, and the person is not in the bathroom during my friends test apparently , so can the actual test detect if the urine was not given that day? It isnt a strip test also, it is a lab test where it is sent somewhere and analyzed. Any info would be appreciated.