Dietary supplements have come under serious fire lately. In February, the attorney general of New York ordered four major retailers to stop selling their popular herbal supplements after tests showed that the products did not actually contain the botanicals listed on the labels. Immediately, this investigation was met with widespread criticism because an inadequate testing method had been used to analyze the supplements. But regardless, this latest snafu serves as a big reminder of just how careful you need to be when shopping for supplements.
Although dietary supplements are regulated by the Food and Drug Administration, they don't undergo near the level of scrutiny that pharmaceuticals do. Unlike drugs, supplements don't have to be tested for safety or efficacy before coming to market. The FDA leaves it up to supplement companies to follow good manufacturing practices and to be able to prove, should it be questioned after the fact, that what they say is in their products is actually in them.
Basically, it's an honor system. And while there are plenty of reputable supplement brands that play by the rules, test their products rigorously, and are very transparent about their ingredients and standards, there are many companies that do none of this. Rather, they'll make crazy claims about their products to try to hook you in, or they'll fill their pills with cheap ingredients not listed on the label. And the way the regulatory system is working right now, they can get away with this — at least for a while.