And there's no evidence that chelation even works for autism; the treatment is based on the unproven theory that children with have heavy-metal poisoning. A 2008 study that evaluated the quality of research on various autism treatments gave chelation the lowest possible grade, saying there are no controlled trials on the safety and effectiveness of chelation as an autism treatment. (Behavioral therapies like applied behavior analysis are considered the best-researched option for treating autism.) That same year, the National Institutes of Health canceled plans to run a clinical trial on chelation for the treatment of autism in children, saying the risks outweighed any potential benefit.
FDA Comes Down on Chelation as Untested Autism Treatment - US News and World Report