<;P>;PROBLEM TO BE SOLVED: To provide a swelling-ameliorating agent containing S-lactoylglutathione and/or a salt thereof. <;P>;SOLUTION: The swelling-ameliorating agent includes the S-lactoylglutathione and/or a salt thereof. The swelling-ameliorating agent can prevent and ameliorate the swelling and the symptoms such as joint pain and accumulation of cellulite, caused by swelling by ameliorating the reduction of the expression of VEGFR3 in the lymph vessel damaged by stimulation from the exterior. <;P>;COPYRIGHT: (C)2011,JPO&INPIT