Colloidal silver

That ingesting suspended silver particles kills all pathogens including those resistant to antibiotics, and treats cancer, without harming the body.

Silver genuinely was used medicinally before antibiotics, which gives the claim its plausible surface. Modern promotion runs through prepper and alternative-health commerce, and it surged during COVID-19 to the point of FTC and FDA warning letters. Alex Jones's Infowars store was among the sellers ordered to stop.

Silver is a real antimicrobial and is still used clinically in exactly two ways: impregnated wound dressings and topical silver sulfadiazine for burns. That is topical use on a surface. Swallowed, it does not produce useful antimicrobial concentrations in blood without also accumulating in skin and organs, which is what causes argyria. The NIH states plainly that colloidal silver is not safe or effective for any internal condition. There is no evidence for the cancer claim.