[Problem] To provide a medical adsorbent for oral administration that has excellent adsorption capacity and selective adsorption of toxins that are to be removed, even at low doses, and that is economical and minimizes environmental impact. [Solution] Activated carbon is obtained by the carbonization and activation of purified cellulose or regenerated cellulose, and is characterized by: comprising granular activated carbon in which the pore diameters are 1.5 to 2.2 nm, the specific BET surface area is 700 to 3000 m2/g, the average particle diameter is 100 to 1100 µm, the amount of surface oxidation is not less than 0.05 meq/g, and the packing density is 0.4-0.8g/mL； and being used as an orally-administered therapeutic agent or preventive agent for renal disease or liver disease.
