Critics of the industry have long warned that you don’t really know what you’re getting when you buy supplements. Over the years, there have been numerous reports of products containing much less, or much more, than what’s listed on the labels. Worse yet, supplements have been found to contain undisclosed prescription drugs, as mentioned above, as well as contaminants such as lead and other heavy metals. To address these concerns, the FDA issued rules that require supplement makers to follow more extensive “good manufacturing practices” (GMPs) to ensure the identity, purity, strength, and composition of their products. This is a good step, but how much of a difference can GMPs really make?
Since DSHEA went into effect, supplements have been regulated under the category of food—and as such, they’ve been covered by GMPs that basically check for sanitary conditions and consistency in production. The newer GMPs, however, are specific for dietary supplements and impose higher standards on these products than food GMPs do. For example, companies are supposed to test all raw materials, set expiration dates based on documented science, ensure that workers are appropriately trained and follow proper procedures, and keep more extensive records, subject to FDA inspection.
Where the GMPs fall short. But the final rules were watered down from the original proposals. Not surprisingly, manufacturers fought against measures that would increase costs. In particular, the provision to test finished products was weakened by various loopholes in the final rules. Notably, products for which there are no validated testing methods, such as herbs, are exempt from testing. In effect, manufacturers can still cut corners and make poor-quality products and get away with it, even if they meet GMPs.
What’s more, the FDA, despite a pledge to substantially increase inspections, lacks the resources to fully monitor compliance, which is often done through inspection of paperwork, not facilities. Still, more than half of 656 FDA inspections of manufacturing facilities conducted in 2017 resulted in letters indicating GMP violations.
What to keep in mind:
• GMPs don’t guarantee safety. Ingredients can still have side effects and unknown long-term effects, interact with drugs, and be dangerous if you have certain medical conditions.
• GMPs have nothing to do with whether a product “works.” Manufacturers of supplements are still not required to submit evidence of effectiveness to the FDA. Even if, say, the glucosamine or ginkgo pills contain what the label states, that does not mean they will relieve arthritis or improve memory, as may be claimed. And if there were a benefit, there’s no guarantee that the suggested dose is the “right” one.
• GMPs do not change how supplements are labeled. Unlike labels on drugs, those on dietary supplements still need not list any precautions, contraindications, or possible drug interactions.
• Many supplements still fail to meet quality standards when put through random testing by independent organizations. GMPs should improve matters somewhat, but so far that is not clear.