<i>Dietary supplements marketed for weight loss and energy, however, do not have to carry such a label. Under a 1994 federal law that has been widely criticized by health authorities, supplements are considered safe until proved otherwise. Unlike prescription drugs, they do not have to be approved by the F.D.A. before they are sold to consumers, nor are they required to list major side effects.</i><p>This has always been a problem with supplements - there is no requirement to disclose content, nor verify effects. This is the first time the down-side risks have been quantified.