There are no clear delineations between classic scientific research, fringe research, and claims made by promoters of alternative medicine and the like.
Since 1996 it has operated the alternative medicine watchdog website quackwatch.org, which advises the public on unproven or ineffective alternative medicine remedies.
In the same way as for conventional therapies, drugs, and interventions, it can be difficult to test the efficacy of alternative medicine in clinical trials.