ETHNOPHARMACOLOGICAL RELEVANCE: In Korean medicine, the steamed root of Panax ginseng C.A. Meyer, known as Korean red ginseng (KRG), is used to invigorate the body, enhance qi, and improve blood flow. It is a potential treatment for cold hypersensitivity in the hands and feet (CHHF), a common complaint among Asians, especially women. However, few studies of its efficacy and safety for CHHF have been conducted. MATERIALS AND METHODS: This randomized, double-blind, placebo-controlled trial included 80 female patients with CHHF at Kyung Hee University Hospital at Gangdong, Seoul, Korea. The participants took six capsules of 500-mg KRG powder or placebo twice daily for 8 weeks and were followed up for 4 weeks. The primary outcome measure was change in skin temperature of the hands. The secondary outcome measures included change in skin temperature of the feet, visual analog scale (VAS) scores of CHHF severity, recovered temperature (RT) of the hands after cold stress test, distal-dorsal difference (DDD) in temperature of the hands, power variables of heart rate variability (HRV), and 36-item Short-Form Health Survey (SF-36) scores. RESULTS: The KRG group had significantly higher skin temperature of the hands and feet, lower VAS scores, higher RT of the right 5th finger, and less parasympathetic activity than the placebo group at 8 weeks. No significant differences were noted in DDD of the hands and SF-36 scores. No serious adverse events were reported during the study. CONCLUSIONS: Peripheral vasodilation by KRG may alleviate CHHF. Further controlled studies are required to elucidate the effects of KRG on the autonomic nervous system.