Although studies suggest homeopathic treatments don't work, the FDA allows them to be sold without testing and without approval from regulators. This week, the agency is re-evaluating that stance. Over two days of hearings, the FDA will listen to public comment as to whether homeopathic remedies should be tested with the same rigorousness as regular over-the-counter drugs.

At the heart of homeopathic medicine are two notions that are not based upon science: the first is that a disease can be cured by a substance that produces similar symptoms in healthy people. The second is that lower doses of a substance produce greater effects. The National Institutes of Health note that "several key concepts of homeopathy are inconsistent with fundamental concepts of chemistry and physics," and that "many homeopathic remedies are so diluted that no molecules of the original substance remain."