I think it does actually, there is Niacin in Red Bull. The sugar free Red Bull, which I have been drinking for awhile, consists of 100% Niacin. I use to drink the sugar free for awhile, one time in specific when I was probation they gave me a random UA at school. I had just had that previous Friday, it was now Monday. Anyhow I dropped the UA and she tested it. I thought for sure I was screwed because I had just smoked 3 blunts that Friday. The test was negative, although it showed some tiny trace amounts of marijuana, which could have easily been inhaled from people smoking around you, so she said. That weekend I was pretty much living on Red Bull, and it came out of my system pretty well. I think if you drink a few Red Bulls each day with some water as well it should come out of your system pretty easy.