Most glutathione brands bought on Amazon pass NOW’s tests

By Hank Schultz

- Last updated on GMT

©Getty Images - FTiare
©Getty Images - FTiare

Related tags Quality assurance Testing label claims potency Adulteration

NOW has released its latest round of testing of products sold on Amazon and found that the glutathione supplements it bought were of reasonable quality, though some failures in potency and purity were still observed.

NOW, which is based in Bloomingdale, IL, has tested other categories of products from Amazon. Among those were curcumin supplements, ALA products, as well as supplements based on CoQ10, SAMe, phosphatidylserine and acetyl-l-carnitine.  Those tests revealed serious deficiencies among the lesser known and lower priced products found for sale on the Amazon platform. 

Of the 13 ALA products tested, for example, NOW found that six had less than 75% of the amount of active ingredient stated on the label, and two had essentially none​. The results from most of the other categories tested were similarly dismal.

The curcumin products performed slightly better,​ but still revealed problems with the undeclared use of synthetic curcuminoids and heavy metals and pesticides tainting or used gelatin caps instead of the claimed veggie caps.

Glutathione products tested better than expected

The glutathione results did not match those dreary expectations.  Of the 19 brands tested, some of which were marketed for skin whitening, only three failed to meet label claim for glutathione dosage.  As with its other testing rounds, NOW did the tests in its own extensive analytical lab as well as sending identical products to Eurofins.

“We were surprised to see less potency failures.  That’s just based on prior testing experiences and the high cost of glutathione,” ​said Dan Richard, NOW’s vice president of sales and the executive who has managed the testing effort.

“It appears that these sources are at full potency and the encapsulating vendors seem to be more honest this round.  It could be that Amazon’s new quality rules regarding ISO17025 approval and documentation requirements are forcing quality higher overall,”​ Richard said.

The glutathione testing found that the majority of the brands tested at 93% or above the claimed dosage on the label.  Many had slight overages of 105% up to 108%, while one product tested at 140%.  One product in this group was not listed among the failures because it made no label claim.  But it contained only 19 mg to 22 mg of glutathione (the NOW and Eurofins results differed slightly), whereas most of the other compliant products claimed to have least 250 mg of the active ingredient (one label stated 167 mg).

Three potency failures, and one odd label choice

Of the three outright failures to match label claim, one product came in at 80% and another at 55%.  A third product claimed a dose of 2000 mcg (micrograms, not milligrams), which could be viewed as a bit of label shenanigans to trick unsophisticated consumers. Even so, that brand did not meet even this inconsequential amount, having only 1 mg instead of 2 mg.

Two of the brands tested above Prop 65 limits for lead content.

New Amazon rules

In December Amazon announced a sweeping set of new rules that sellers of supplements must meet​ in order to list their products on its site.  The new rules specify that a product must:

  • Meet the potency claims stated on the label
  • Be manufactured in compliance with GMP rules
  • Use only lawful and safe ingredients as defined in federal regulations
  • Use ingredient concentrations that are deemed safe for human consumption.

NOW has made it a practice to forward its testing results on to Amazon.  The online retailing giant hasn’t responded directly. There was been no indication that the changes it made could be attributed to the bad press from the tests or pressure from other industry stakeholders.

“We do ask and ask again and have been unable to get feedback from Amazon,” ​Richard said.

Richard said NOW isn’t finished trying to expose poor quality products sold on the Amazon site.

“We plan to pause for a while and start up again in 2022 with different products we suspect are likely to be problematic,”​ he said.

Amazon did not respond to request for comment.

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