OBJECTIVE This study aims to assess the effects of proanthocyanidin-a class of polyphenol antioxidants extracted from grape seeds-on menopausal symptoms, body composition, and cardiovascular parameters in middle-aged women. METHODS We conducted a randomized, double-blind, placebo-controlled study in 96 women aged 40 to 60 years who had at least one menopausal symptom. The study participants were randomized to receive grape seed extract tablets containing either low-dose (100 mg/d) or high-dose (200 mg/d) proanthocyanidin, or placebo, for 8 weeks. Their menopausal symptoms were evaluated using the Menopausal Health-Related Quality of Life Questionnaire, Hospital Anxiety and Depression Scale, and Athens Insomnia Scale before and after 4 and 8 weeks of treatment. Body composition and cardiovascular parameters were also measured. RESULTS A total of 91 women (95%) completed the study. Background characteristics, including age, menopause status, subjective symptom scores, body composition, and cardiovascular parameters, were similar among the groups. The following significant changes were observed during the course of the study: (1) physical symptom score, hot flash score, and (2) Athens Insomnia Scale score decreased in the high-dose group after 8 weeks of treatment; (3) Hospital Anxiety and Depression Scale Anxiety score and (4) systolic and diastolic blood pressure decreased in the low-dose and high-dose groups after 4 weeks; and, (5) lastly, muscle mass increased in the low-dose and high-dose groups after 8 weeks of treatment. CONCLUSIONS Grape seed proanthocyanidin extract is effective in improving the physical and psychological symptoms of menopause while increasing muscle mass and reducing blood pressure in middle-aged women.