The Japanese plant ashitaba (Angelica keiskei) contains flavenoid chalcones, 4 hydroxyderricin and xanthoangelol has been shown to prevent aspects of metabolic syndrome. A two-part pilot study was undertaken to determine ashitaba's effect on body weight, waist circumference visceral fat in overweight adults. There were two 8 weeks randomized, placebo-controlled, double-blind parallel studies. Part 1: 15 healthy males and Part 2: 26 overweight adults. The treatment groups received 200 mg/day ashitaba chalcone powder (8%) and control groups received a placebo daily. Weight, visceral fat, subcutaneous fat, total fat, BMI, waist circumference and body fat were measured at baseline, weeks 4 and 8. Subjective symptoms, blood tests, urine test, heart rate, blood pressure were conducted to determine safety. There were no significant differences between groups in primary endpoints or safety measures. There was a significant reduction of the visceral fat area and body weight in the treatment group at 8 weeks compared to baseline particularly in those with the highest amount of visceral fat. A decrease in the visceral fat and body weight over 8 weeks was significant only in the treatment group, suggesting future studies are warranted. The study supports the safety of the product.