What would niacin be used for drug relative?

niacin is a calcium supplement, which often clears drugs test if taken in large amounts... but it also has really bad side effects if you take to many, sweats, itchiness, lack of sleep. And depending on what kind of drug test it is.. the niacin can show up if the drug test is very high quality.. and normally when you fail for that they no what your trying to do.. clear it. So yes it works but its a real hassle.