Abstract
The increasing availability of colloidal silver dietary supplements raises important concerns regarding their safety when used for oral consumption. This study presents the physicochemical characterization of a commercial colloidal silver solution with a high concentration (1000 mg/L), stabilized with pectin in distilled water. The characterization was performed using UV-VIS, XRD, and TEM. The manufacturer did not provide information regarding nanoparticle size or recommended duration of use. The 1000 mg/L sample was also compared with a standard colloidal silver solution provided by Sigma Aldrich to validate nanoparticle size, stability, and spectral profiles. In addition, a comparative theoretical analysis was conducted on other commercially available products containing colloidal silver at concentrations of 15, 30, 55, 80, and 125 mg/L, based solely on the recommended daily intake and the oral reference dose of 0.005 mg/kg/day established by the United States Environmental Protection Agency (EPA). Although no in vivo or in vitro toxicity tests were performed, the results indicate a potential toxicological risk due to estimated intake levels that may exceed safety thresholds, particularly in high-concentration products with insufficient labelling or unclear usage guidelines. These findings emphasize the need for stricter regulatory measures and greater public awareness regarding the internal use of colloidal silver supplements.