NOW, a company specializing in dietary supplements, recently tested several magnesium glycinate products which it purchased on Amazon.
 
The latest round of testing follows similar tests on products from lesser-known brands containing CoQ10 and quercetin, phosphatidylserine, curcumin, ALA, glutathione, and more.
 
According to the company, test results showed misleading and inaccurate labeling, and that many of the products didn’t contain the material they claimed, didn’t contain the material in the right form, or didn’t contain the right amount of claimed material.
 
Almost all brands tested failed to include the chelated magnesium form as claimed on the respective labels. Magnesium chelates such as magnesium bisglycinate or glycinate are valued due to their water solubility and lack of a laxative effect. These forms are also more expensive than others, and are at risk of economically-motivated adulteration with a lower-quality material such as magnesium oxide and magnesium carbonate, which are blended with glycine, according to NOW.
 
NOW compared two of its own products in tests as well, and all products were subjected to testing at NOW’s in-house lab as well as at a Eurofins contract laboratory. Total magnesium content was determined by analyzing samples using Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES). To determine levels of water-soluble magnesium glycinate, the same ICP-OES technology was used, but instead of acid digestion, a gentle water extraction was applied to all samples.
 
Twelve out of 16 tested products met the label claim when tested for total magnesium content.  However, NOW reports that only its products met the label claim when they looked at the soluble (chelated) form of magnesium, suggesting that other brands use non-soluble forms of magnesium in place of the more expensive chelated form. Glycine was also detected in all samples, however, soluble magnesium test results suggest that glycine was not or not entirely bound with magnesium.
 


“Unfortunately, it is known in the industry that many brands either knowingly or unknowingly simply blend glycine with magnesium oxide or carbonate and then label the product as ‘magnesium glycinate,’” said Dan Richard, NOW’s Vice President of Global Sales and Marketing.  “The difference is that the improperly labeled product is much lower cost and is not a fully reacted or bonded chelate.” 
 
Further, some brands appeared to mislabel in order to get higher label potency claims, according to NOW. For instance, a brand called Deal Supplement claimed their product contained 750 mg of magnesium glycinate per capsule, but labeling requirements dictate that a label should list the elemental dose of magnesium and not the total weight of an RDI ingredient. Other brands which mislabeled this way included Innate Vitality, Naturebell, Terranics, and ZYY Nutrition, NOW reported.

NOW intentionally didn’t test other brands’ products that claimed to use Albion Minerals, which it uses for its own products.
 
NOW noted that some brands such as Toniiq claimed that their magnesium glycinate was 20% elemental, but this could only be achieved if the magnesium and glycine in an ingredient are not fully reacted/bonded together. NaturaLife “buffered” its magnesium, which had 18% potency with Albion as the source, with magnesium oxide, which was included on the side panel of the product. Only magnesium glycinate was listed on the front of the product, NOW said.
 
“It’s disheartening to see consumers misled and cheated when they buy products on Amazon, over and over again,” said Richard. “This should matter to everyone in our industry. Consumers may grow to trust the entire supplements industry when not getting the benefits they expected and deserved and companies that work hard to do things right are losing sales to these bad actors.”