The paper presents a physicochemical study of the water-soluble adduct of C60 with l-arginine, including a quantum chemical determination of the stability of isomers, measurement of antiradical activity towards the ABTS radical, determination of the lipophilicity coefficient, particle size distribution in aqueous solutions and calculation of ζ-potentials. A separate part of the article is devoted to the study of the effect of the C60 adduct with l-arginine on DNA in in vitro experiments (determination of the binding constant using isothermal titration calorimetry, study of genotoxicity, DNA melting temperature, effect on DNA circular dichroism spectra). Data are also presented on the biodistribution of the C60 adduct with l-arginine in the organs and tissues of animals and its effect on clinical and biochemical blood parameters. The mutagenic effect of the C60 adduct with l-arginine was determined in vivo on a model of mice abnormal sperm heads. It was shown that the adduct is in a neutral state in physiological solution, has an affinity to both aqueous and lipid phases (logPow = 0.23), and forms a complex with DNA (Ka = 4.59 106 M −1), while it does not have cyto- and genotoxicity in vitro and mutagenicity in vivo.