When the cause became apparent, reputable doctors stopped recommending their use, and reputable manufacturers stopped producing them. The official United States drug guidebooks have not listed colloidal silver products since 1975. Silver nitrate sticks are still legitimately used to cauterize certain wounds, but this does not cause silver to accumulate in the body. The ban applies to all products labeled, represented, or promoted for the treatment or prevention of any disease. The FDA has warned more than 20 companies to stop making illegal claims for colloidal silver products that they were marketing through the Internet.
Promoters claim that their products contain too little silver to cause argyria.
Because dietary supplement quality is not regulated, however, buyers have no way to ensure that the amounts stated on the label actually represent the amounts in the product. Other studies have found concentrations ranging from zero to considerably higher. The situation is further complicated because many people are making their own colloidal silver with devices sold for that purpose. His doctors diagnosed argyria after a laboratory test showed that the level of silver in his blood was 85 micrograms per liter. The amount of silver required to produce argyria is unknown.