The trouble with bright futures is that the path is rarely crystal clear. If you’re looking for non-GMO supplements, that path includes tricky terrain across dimly lit links in the supply chain.

With Whole Foods requiring labeling of genetically modified organisms by 2018, Vermont mandating the same by 2016, and millions of shoppers now clamoring for all things non-GMO, supplements companies are lining up to get the coveted Non-GMO Project Verified butterfly on their labels. Roughly 800 supplement products from 100 brands have already made the cut, and 120 more soon will. Non-GMO Project Verified options rank among the fastest-selling supplements, with 2014 sales topping $160 million, up 13.5 percent over 2013.

 “Supplements companies are realizing that people no longer base their purchasing decisions on brand loyalty alone; they also look for the Non-GMO Project seal,” says Kelly Mae Heroux of Food Chain ID, a cofounder and technical administrator for the Project. But verification isn’t easy—and in some cases, it won’t be possible. 

What it takes to get the seal

For any product, “testing, tracing, and segregation” form the basis of the complex verification process, says Aaron Sanger, director of standards and technical administration for the Non-GMO Project. Companies must provide documentation that all major ingredients either have no risk of being derived from GMOs or have been tested and fall below established thresholds (for supplements, that’s 0.9 percent). All ingredients, however minor, must be traced to determine GMO status. And to prevent GMO contamination, manufacturers must segregate ingredients that meet the standard from those that don’t.

For companies that buy ingredients from international markets—where GMO standards vary by country, trade secrets are held close, and language barriers can muddy transactions—this can be a colossal undertaking. “If you have a corn chip with five ingredients, that’s one thing,” says Sara Newmark, director of sustainability for New Chapter, the first supplements company to achieve Non-GMO verification. Supplements often contain dozens of ingredients, many made via multilayer processes. “The verification process was created for food,” Newmark says, “and the supplements industry is trying to fit within that mold.”

Snags in the system

Vitamins are a particular trouble spot, with genetically modified corn serving as the fermentation medium for vitamin C, distilled GM soy oils yielding vitamin E, and several B’s manufactured with genetically altered microorganisms. GMOs are particularly ubiquitous in enzymes, often grown using high-risk crops (such as papaya) or GM yeasts, bacteria, or fungi. And probiotics are often cultured on GM sugar beets or milk from cows that eat GM feed.

In Europe, all animal-derived ingredients, such as lanolin-based vitamin D, are excluded from non-GMO assessment. But the Project includes them, reflecting concerns that GMOs in feed might negatively affect livestock and ultimately end up inside a product. That means supplements manufacturers must not only assure that an animal was not cloned but must also trace every morsel it ever ate.

“Products from animals are often just collected as a byproduct,” says Heroux. It’s indescribably complicated to prove that every source followed Project guidelines.

More and better options

Difficulties aside, forward-looking supplements makers applaud the Non-GMO Project for ushering in a new era of supply-chain openness, sparking ingredient innovation, and inspiring R&D for alternatives. Sanger says the Project continues to explore the idea of a separate process for supplements. “Ultimately, we want to retain the standard’s attainability and the meaningfulness because it’s the most pragmatic way to change the overall supply chain,” he says. Today, several competing product-verification projects are in the works or already available, such as Natural Food Certifiers’ “GMO Guard,” launched in 2013.

Should there be a separate process for supplement non-GMO verification?