How long does it take for niacin to clean marijuana out of your system?

Taking niacin will not make you pass a drug test.

Firstly, the presence of niacin does not affect the presence of many other chemicals, and these are what are tested. For example, the various naturally secreted chemicals in urine and saliva, or the ones that should/would be present if you were taking drugs.

Secondly, any levels which are beyond the accepted normal - that includes either being too low (dilution) or too high (added extras to mask) - and cannot be medically explained such as by a natural condition or by medicines being taken will result in an automatic fail.

Finally, niacin in high levels is toxic. That is it can kill you. Niacin overdose symptoms include:

• Severe skin flushing combined with dizziness
• Rapid heartbeat
• Skin rash and itching
• Nausea and vomiting
• Abdominal pain
• Diarrhea
• Severe liver damage (hepatoxicity)