Considering the above, we aimed at investigating the interaction between COSAN and DNA using a wide range of spectroscopic, calorimetric, and other physicochemical techniques, such as UV-Vis absorption spectroscopy, circular (CD) and linear (LD) dichroism, and nuclear magnetic resonance (NMR). In addition, we performed thermal denaturation, viscosity, differential scanning calorimetry (DSC), isothermal titration calorimetry (ITC), and equilibrium dialysis measurements. Adequately characterizing COSAN-DNA interactions is crucial for further advancing metallacarborane-based drug development and for addressing safety concerns because DNA-binding molecules often have associated mutagenic, cancerogenic, or teratogenic activity. This knowledge will facilitate the rational design of metallacarborane-based drugs and unveil their molecular mechanism of action, thereby overcoming current limitations to metallacarborane applications in medicinal chemistry.