Researchers in this investigation found that low doses of an Alcohol extraction (
but NOT a water extraction
) of American ginseng increased human breast cancer cell proliferation in a breast cancer cell line. High doses inhibited breast cancer cell growth in both the alcohol and water extracts. Therefore, American ginseng should be safe to use with breast cancer patients if you make a tea from it, or if you use the alcohol extract in high doses.
 
Integr Cancer Ther. 2006 Sep;5(3):236-43.