How long can after smoking marijuana can it be detected in urine?

I think you may have meant to ask how long before they no longer test positive. Because a chronic smoker will test positive within a short period of time. A chronic smoker should give it a week and a half to two weeks of abstaining before a urine test shows negative. Up those vitamins, and ginseng and drink ALOT of water I mean 10 - 12 glasses a day and don't take caplet vitamins take liquid or gel caps. The hard vitamins usually just pass through your system they are a complete waste most of the time.