We administered Bofutsushosan (Bo) to 127 obese patients who consulted our clinic, and investigated the effect of this herbal formula on reducing body weight in 33 obese patients who received continuous adminis tration for more than six months. The abdominal muscle tension of these 33 patients was assessed mainly as “strong” (four) under the five-grade scale of Kampo diagnostics, which was higher than that of 9 other patients with side effects (including diarrhea and abdominal pain) assessed mainly as “middle” (three). Sixteen patients reported a decrease in appetite following administration of Bo. Weight before medication in the patients with decreased appetite was 67.1±2.5kg, and that in 17 patients with unchanged appetite was 75.9±2.4kg. There was a significant difference between the two. Weight change in the patients with decreased appetite was -4.8±1.0kg and was significantly lower than -1.4±0.7kg in the patients with unchanged appetite. Their blood triglycerides levels decreased significantly following administration of Bo. This decrease in appetite was considered to be due not only to activation of the adrenaline β₃ receptor, through the administration of Ephedrae Herba, Schizonepetae Spica, Rhei Rhizoma, Forsythiae Fructus and Glycyrrhizae Radix but also to the psychotropic actions of Ephedra Herba, Rhei Rhizoma and Gardeniae Fructus. Recently severe side effects of Bo have been reported. This study suggested that patients showing a grade of strong (four) or more in abdominal muscle tension, were indicated for this treatment and that the long-term administration of this herbal formula should be continued in patients whose appetite was identified as being suppressed.