Brown adipose tissue (BAT) is related with energy expenditure, in contrary to fat-storing white adipose tissue. Recent studies have shown that cold exposure could be related with the expression of BAT in adult subjects assessed by (1)(8)F-fluorodeoxyglucose (FDG) positron emission tomography (PET). In addition, the application in previous clinical trials showed positive effect of xanthigen containing fucoxanthin and punicic acid on body weight and liver fat content. In this short-term intervention study, we evaluated the effect of xanthigen on the expression of BAT by (1)(8)F-FDG PET. Two healthy obese premenopausal women were enrolled and xanthigen 600 mg (2 capsules including fucoxanthin 3 mg, punicic acid 174 mg) was given for 3 months without dietary and exercise intervention. Body composition and dietary intake were assessed monthly. Laboratory test and (1)(8)F-FDG PET were performed before and after intervention. After intervention, there was neither weight reduction nor remarkable laboratory change. However, BAT, assessed by (1)(8)F-FDG PET, was detected in both cervical, supraclavicular and paravertebral space in one subject, even though her body weight showed mild increase. This result suggested that xanthigen can induce BAT in a healthy adult. However, a further large well-controlled study is needed.