With the constant drumbeat of GMP violations, FTC enforcement actions, scientific discrediting, negative supplement studies and the specter of NDI regulation, the supplement industry has plenty to worry about. But let’s go ahead and let another hornet into the house: magnesium stearate.
A nonpareil in the excipient world, magnesium stearate (or magnesium salt) is an inactive filler used widely in supplement tableting and encapsulation. Because of its lubricating properties, magnesium stearate is especially useful in manufacturing because it keeps ingredients from sticking to equipment during compression and mixing. Lacking an effective alternative, the excipient is nearly ubiquitous in supplement manufacturing.
But, according to a subcommittee of Codex Alimentarius—the world authority on international food standards—magnesium stearate has no known use in food, despite its lengthy history of use in supplements.
(Take a deep breath—prepare for acronyms.) A report from the Electronic Working Group (EWG) of the International Numbering System (INS) submitted to the 42nd Session of the Codex Committee on Food Additives (CCFA) in March 2010 recommended that “magnesium salts of fatty acids” be deleted from the Codex for no known use.
The potential impact would be deleterious to a supplement industry dependent on the excipients. So, a year later, (heads up—more acronyms) the International Alliance of Dietary Supplement Associations (IADSA) submitted a request to the 43rd Session of the CCFA in March 2011 that magnesium stearate be reinstated as a food additive—which it was, under INS number 470(iii).
However, (not out of the woods yet) the Joint Expert Committee on Food Additives (JECFA) now requires toxicity data to substantiate magnesium stearate’s new standing, despite its existing history of use in supplements. According to John Venardos, senior vice president of regulatory affairs for the global network marketing company Herbalife, who presented this issue at the recent NIA West conference in Laguna Beach, the estimated cost of this tox data on magnesium stearate would cost $180,000. No manufacturer has yet volunteered to foot the bill.
Without a favorable opinion from JECFA, however, use of the ingredient could be discontinued.
Some manufacturers may smile at magnesium stearate’s peril. Hypoallergenic supplement companies—such as Thorne Research or Pure Encapsulations—call out their lack of fillers, binders and excipients as a point of differentiation.
But most large-scale manufacturers would likely be scrambling were this ingredient to hit the skids.
What say you, manufacturers? Is there a viable alternative to magnesium stearate?