A uric acid-lowering agent containing, as an active ingredient, a tyrosine-containing cyclic dipeptide selected from the group consisting of cyclotryptophanyltyrosine, cycloseryltyrosine, cycloprolyltyrosine, cyclotyrosylglycine, cyclotyrosyltyrosine, cyclophenylalanyltyrosine, cycloleucyltyrosine, cyclolysyltyrosine, cyclohistidyltyrosine, cycloalanyltyrosine, cycloglutamyltyrosine, cyclovalyltyrosine, cycloisoleucyltyrosine, cyclothreonyltyrosine, cycloaspartyltyrosine, cycloasparaginyltyrosine, cycloglutaminyltyrosine, cycloarginyltyrosine, cyclomethionyltyrosine, and cyclotyrosylcysteine, or a salt thereof. The uric acid-lowering agent of the present invention has an excellent action of lowering a uric acid level, and the uric acid-lowering agent is useful in, for example, prevention or treatment of hyperuricemia, gout or the like.一種尿酸值降低劑，其係以選自由環色胺醯基酪胺酸、環絲胺醯基酪胺酸、環脯胺醯基酪胺酸、環酪胺醯基甘胺酸、環酪胺醯基酪胺酸、環苯基丙胺醯基酪胺酸、環白胺醯基酪胺酸、環離胺醯基酪胺酸、環組胺醯基酪胺酸、環丙胺醯基酪胺酸、環麩胺醯基酪胺酸、環纈胺醯基酪胺酸、環異白胺醯基酪胺酸、環蘇胺醯基酪胺酸、環天門冬胺醯基酪胺酸、環天門冬醯胺醯基酪胺酸、環麩醯胺醯基酪胺酸、環精胺醯基酪胺酸、環甲硫胺醯基酪胺酸、及環酪胺醯基半胱胺酸所成群組的含有酪胺酸之環狀雙肽或其鹽為有效成分。本發明之尿酸值降低劑，係具有優良的尿酸值降低作用者，有用於例如高尿酸血症或痛風等之預防或治療。
