This study concerns the biological effects and physico-chemical variations of extremely diluted solutions (EDS) as a function of aging-time. The biological efficacy of As 2 O 3 at the 45th decimal dilution/succussion (As 45×) was tested in a wheat germination model. Ten trials were carried out from 0 to 12 months after treatment preparation, using wheat seeds (Triticum aestivum L.) of the Pandas variety. Seeds were pre-treated by poisoning with 0.1% As 2 O 3 solution to reduce germination, to allow a better evaluation of treatment effects. The outcome variable was the number of non-germinated seeds after 96 h. The As 45× treatment aged for less than three months did not show a significant effect on wheat germination, whereas when aged for longer (3-12 months) the effect became significant. Concerning the physico-chemical characteristics, specific conductivity of As 45× aged from 0 to 12 months was measured, using nine samples for each date. The results showed a clear increasing time trend of specific conductivity, more evident when considering the last three measurements, which correspond to more than six months of aging. The physico-chemical behavior of EDS strongly supports the significant biological effects observed in a wheat model.