Purification Rundown, a program used by Scientology, was investigated by the New York Press, who found that there was no peer-reviewed research about it.
Scientologists consider it the only effective way to deal with the long-term effects of drug abuse or toxic exposure. An investigation by the New York Press asked a number of independent doctors about the evidence for the Purification Rundown. None of them endorsed the program's effectiveness and some explicitly described it as dangerous. Several said that no peer-reviewed research on the rundown had been published in any medical journal. 
