The present invention aims to provide an adsorbent for oral administration comprising ACF that has high adsorption or removal performance by adsorbing or removing toxic substances in the living body greatly and rapidly. The present invention is an adsorbent for oral administration comprising activated carbon fibers for treating or preventing kidney diseases or dialysis complications.本發明係以提供大量且迅速地吸附或去除身體內毒性物質之含具有高吸附性能或去除性能之活性碳纖維之經口投與用吸附劑為目的。本發明係含活性碳纖維之經口投與用吸附劑，為腎病之治療或預防藥，或透析合併症之治療或預防藥。
