This exploratory study characterized nanoparticles (NPs) in homeopathically-prepared silver medicine (Argentum Metallicum), succussed and unsuccussed control solutions. Methods included nanoparticle tracking analysis (NTA), zeta potentials, inductively-coupled plasma mass spectroscopy (ICP-MS) for silver, and ultraviolet visible spectroscopy (UV-vis). Homeopathy is a 200 year-old traditional medical system using mineral, plant, and animal sources to treat patients. Debate over the efficacy of homeopathic medicines (HMs) stems from its unique manufacturing methods involving dry milling in lactose and/or serial dilutions and succussions (intense agitation) in water or water-ethanol solvent. The present study examined commercially-made, randomized and blinded verum Argentum Metallicum HMs and succussed solvent controls at 6C, 30C, and 200C potencies, and unsuccussed solvent (95% v/v ethanol) in corkstoppered glass vials. NTA revealed >2 × 10 8 NPs/ml in 20 of 21 samples, with extensive polydispersity. Verum NP characteristics differed significantly from controls: (a) Although Verum 200C exhibited the highest NP concentrations and exemplar transmission electron microscopy of one Verum 30C sample showed scattered silver-like dark NPs embedded in an organic matrix, ICP-MS could not reliably detect elemental silver at 1 ppb (lower limits of instrument detection); (b) verum NPs were significantly larger sized across potencies (91 nm) versus unsuccussed controls (53 nm); (c) zeta potentials of verum NPs (mean-44 mV) were significantly more negative than the unsuccussed controls (mean-20 mV); (d) succussed controls were intermediate in NP concentrations and sizes between verums and unsuccussed controls; (e) All samples showed UV-vis absorbance peaks near 200-350 nm wavelengths, consistent with organic cork extract. Taken together, the findings suggest polydisperse heterogeneous nanohybrid mixtures of silver, silica shell/ silver core, silica NPs, and perhaps cork exosomes, self-assembled and surface-stabilized by silica coatings, organic plant extract (cork), and/or lactose in verums. Glassware-derived silica from succussions may contribute NPs and coatings for nonlinear source signal amplification to initiate clinical effects.