Clinical Studies

Three of the included studies explored American ginseng for management of CRF. Barton and colleagues completed a pilot study evaluating three different doses (750 mg, 1,000 mg, and 2,000 mg) of daily American ginseng (specifically Wisconsin ginseng, a common type of American ginseng), as compared with placebo. The duration of treatment was 8 weeks for each treatment arm. Patients included in this study were varied regarding treatment history and cancer type. Across all cohorts, 57% were undergoing active chemotherapy and 18% were receiving current radiation therapy; cancer types in the study consisted of breast (n = 109), colon (n = 29), lung (n = 35), and "combination/unknown/other" (n = 109). No significant difference in activity interface or usual fatigue between placebo and treatment arms was significant; however, a subset analysis reported a trend towards improvement of fatigue in the cohort using a daily dose of 2,000 mg.

In the phase III trial using a dose of 2000 mg of American ginseng daily, at 8 weeks there was a significant improvement of fatigue by ~18% to 22% in the American ginseng group compared with 7% to 18% in the placebo group. Greater benefit was reported in patients receiving active cancer treatment compared with those who had completed treatment.¹⁵ Serious adverse events were low (approximately 3%) and did not significantly differ between groups.

Importantly, American ginseng appears not to inhibit the cytochrome p450 system²⁸ and has not been found to impact the effects of tamoxifen, doxorubicin, cyclophosphamide, paclitaxel, 5-fluorouracil, and methotrexate, but was instead synergistic with these agents inhibiting growth in MCF-7 breast cancer cell lines.