However, doctors and other research indicate that immediate-release niacin, like that used in the purification rundown, can also be harmful to the liver and that the other side effects are no happy byproducts of detoxification.If you give people this much niacin, science has shown that those are the symptoms of niacin toxicity, said Saeed A. Jortani, Ph.D., the director of the forensic toxicolog