Remedies for diabetes having an effect of lowering the blood glucose level without substantially elevating the blood lactic acid level. These remedies are characterized by containing, as the active ingredient, biguanide derivatives represented by the following general formula (1) wherein R<1> represents a group selected from the following ones: or salts thereof. Remedies having the above constitution, which exert an effect of lowering the blood glucose level without substantially elevating the blood lactic acid level, can be administered to diabetics frequently suffering from lactic acidosis associated with renal function disorder.
