An orally administered adsorbent which has a high ability of adsorbing indoxylsulfuric acid, indoleacetic acid, and indole, a method permitting easy and advantageous production of the same, and a drug using the same. The orally administered adsorbent is obtained from spherical particles of activated carbon by carbonizing and activating spherical particles of a furfuryl alcohol resin obtained by resinifying furfuryl alcohol through a self-condensation reaction and curing the resinified furfuryl alcohol.