Many popular probiotic supplements were tested by Consumer Lab, an independent agency that monitors vitamins, herbal remedies, and supplements not regularly tested by the government. The lab's findings are a bit startling. Some of the products contain as little as 13 percent of the amount of "viable bacteria" claimed on the products' labels, although most products do contain one billion organisms — the amount needed to register some health benefits.
When it comes to misleading marketing with these supplements, much of the problem stems from the fact that the term probiotics has no legal definition and can be used loosely by manufactures. Of the supplements tested, ConsumerLab ranked Advocare Probiotic Restore, GNC Nature Brand Best Super Acidophilus, and Jarrow Formulas Jarro-Dophilus as having the highest quality. You can buy a full review from Consumer Lab for $12.