PROBLEM TO BE SOLVED: To suppress the activity decrease of orally administered physiologically active peptide or protein. SOLUTION: An activity lowering inhibitor of a physiologically active peptide or physiologically active protein containing a sulfate group-containing polysaccharide as an active ingredient. A method for suppressing a decrease in activity of a physiologically active peptide or physiologically active protein, which comprises adding a sulfate group-containing polysaccharide to the physiologically active peptide or physiologically active protein. [Selection diagram] None【課題】経口投与された生理活性ペプチド又は生理活性タンパク質の活性低下を抑制すること。【解決手段】硫酸基含有多糖類を有効成分とする生理活性ペプチド又は生理活性タンパク質の活性低下抑制剤。生理活性ペプチド又は生理活性タンパク質に硫酸基含有多糖類を添加することを含む、生理活性ペプチド又は生理活性タンパク質の活性低下抑制方法。【選択図】なし
