In order to design magnetic carriers for medical drugs, carbon-supported iron samples with an iron content of 23, 29 and 43 wt.% have been prepared by impregnation of synthetic carbon with aqueous solution of iron oxalate followed by calcination and by reduction in hydrogen. The samples obtained after reduction times of 15, 30, 45 and 60 min have been characterized by Mössbauer spectroscopy, X-ray diffraction (XRD), and magnetization as well as adsorption measurements. Analysis of the Mössbauer and XRD data shows the presence of both oxidic and metallic iron particles with sizes in the 3-30 nm range. The saturation magnetization of the carbon loaded with 23, 29, and 43 wt.% iron has been determined to be 20. 30 and 80 emu per gram of solid, respectively. The hydrogen treatment induces in addition an increase of the meso- and macropore volumes of the iron-loaded carbon by a factor of about 1.4 with respect to the unloaded carbon. This fact is shown to lead to a better adsorption capacity for macromolecular drugs like streptomycin and vitamin B12.