A post on Instagram has made the unusual claim that colloidal silver cannot turn your skin blue, prompting the platform to place a "false-information" label and link to independent fact-checkers.
First, a bit of background. Colloidal silver supplements are touted to treat hay fever and skin conditions, as well as a variety of other ailments, despite no good scientific evidence to support any of these claims. Prior to the invention of penicillin, silver nitrate was used to treat wounds as a method of dealing with infection. With the discovery of penicillin, its use all but stopped, due to the effectiveness of penicillin and its safety compared to silver compounds.
Nevertheless, people still use colloidal silver and defend it as a supplement, leading to a strange Instagram post (itself a screenshot of an earlier Reddit post) claiming that colloidal silver will not turn your skin blue.
"It's impossible for colloidal silver to turn you blue. That's why FDA hasn't been able to ban it," the post read, with an accompanying photo of Paul Karason, who famously turned blue after taking colloidal silver for acid reflux and arthritis.
"Not one person has turned blue. Ever. This clown made a home brew concoction that wasn't silver, and went on Oprah."
Several other conspiracy theories have also made the rounds about Karason.
But, as was noted by the fact-checkers of the Instagram post, this claim has no basis in fact. Karason, who became known as "Papa Smurf", did gain his blue tinge due to the condition known as argyria, or silver poisoning.
"Generalized argyria is characterized by slate-gray to blue discoloration of the skin caused by cutaneous deposits of silver particles after long-term ingestion of solutions containing colloidal silver ingredients or silver salts," a letter on the topic in the journal Dermatology explains.
"The skin discoloration is more prominent in sun-exposed areas and is usually permanent. There is no widely accepted effective treatment for the skin discoloration of argyria."
It's also not true to say that there have been zero cases of people turning blue due to supplements, with cases of this exact type reported in the medical literature.
Though the U.S. Food and Drug Administration (FDA) has not banned the substances, they have warned "over-the-counter drug products containing colloidal silver ingredients or silver salts for internal or external use are not generally recognized as safe and effective," and will not allow colloidal silver products to make medical claims.
"FDA is not aware of any substantial scientific evidence that supports the use of over-the-counter colloidal silver or ingredients or silver salts for these disease conditions".
In summary: No evidence of benefits and turns you blue. Probably best to avoid.