An object of the present invention is to provide an orally administered adsorbent capable of adsorbing large quantities of tryptophan or indoxyl sulfate in the presence of bile acid. Accordingly, the above object can be solved by an orally administered adsorbent characterized by containing surface-modified spherical activated carbon having bulk density from 0.30 g/mL to 0.46 g/mL, a specific surface area determined by the Brunauer-Emmett-Teller (BET) method of not less than 1900 m2/g, total acidic group content from 0.30 meq/g to 1.20 meq/g, and total basic group content from 0.20 meq/g to 0.9 meq/g.
