in august 1999, the u.s. fda banned colloidal silver sellers from claiming any therapeutic or preventive value for the product, although silver-containing products continue to be promoted as dietary supplements in the u.s. under the looser regulatory standards applied to supplements. the fda has issued numerous warning letters to internet sites that have continued to promote colloidal silver as an antibiotic or for other medical purposes. despite the efforts of the fda, silver products remain widely available on the market today. a review of websites promoting nasal sprays containing colloidal silver suggested that information about silver-containing nasal sprays on the internet is misleading and inaccurate.