Source 1:
7.2 Drug screens that do not work:
"Niacin has been shown to work on occasion. Byrd Labs tests conclude that niacin doesn't work at all. In other words, something else probably caused a negative, not the niacin."
Source 2:
Dr. Manoj K. Mittal, of a Philadelphia hospital reports that four patients presented to the E.R. due to adverse Niacin reactions. Two of the four Philadelphia patients exhibited nausea, rapid heartbeat and heart palpitations, dizziness, dehydration, low blood sugar, blood-clotting abnormalities, liver toxicity, and a dangerous drop in blood pH (
www.sciencenews.org). One seventeen-year-old girl was brought to the E.R. in a coma as a result of too much niacin.
These patients tested positive for marijuana in a urine test conducted at the hospital. So obviously, the niacin did not "flush" the drug away.
Source 3:
People taking pharmacological doses of niacin (1.5 - 6 g per day) often experience side-effects that can include dermatological complaints such as facial flushing and itching, dry skin, skin rashes including acanthosis nigricans. Gastrointestinal complaints, such as dyspepsia (indigestion) and liver toxicity (fulminant hepatic failure) have also been reported. Also reported include hyperglycemia, cardiac arrhythmias, birth defects, and orthostasis.
Source 4:
The concept that revolves around the relationship between niacin and drug test can be very risky. The problem with taking niacin in large doses is that it leads to unwanted side effects. The most notable side effect that is immediately felt is skin flushing and warmth, which may be coupled with itching and rashes. Adverse reactions to niacin are also possible which can range from gastrointestinal problems (nausea, vomiting, diarrhea, abdominal cramps, among others) to liver complications. While there has not been any fatalities with the use of niacin for drug testing and the side effects being reversible, the danger that you put yourself through may not be worth the risk.
If you want to beat a drug test, think outside of the box... are we allowed to talk about drug testing in here anyways?
In one of my sources is the most likely reason Niacin could eliminate the metabolites of marijuana from your body (that I can see), it is: "and a dangerous drop in blood pH". Like I said, think outside of the box.