Uses of American GinsengThe evidence supporting the health benefits of American ginseng is limited, most of which comes from lab and animal studies. Human trials are lacking.4
With that said, a growing body of research suggests that American ginseng may be beneficial in the treatment of fatigue, poor memory, diabetes, and viral respiratory infections like colds and flu.
A 2018 review of four studies suggests that American ginseng may help relieve fatigue caused by chronic illnesses ranging from chronic fatigue syndrome (CFS) to cancer. The most significant benefit was seen in people who took 2,000 milligrams (mg) daily for eight weeks.6
Similar results were seen in a 2019 review examing the effects of American ginseng on people with cancer-related fatigue. In this study, the benefit was greatest in people undergoing active treatment, like chemotherapy or radiation.7
As an added bonus, American ginseng does not interact with commonly prescribed chemotherapy drugs like tamoxifen, doxorubicin, methotrexate, or fluorouracil.7
Limited evidence suggests that American ginseng may improve cognitive function in some people. This includes the ability to learn, think, reason, and remember.
A 2015 study reported that healthy adults who received a single 200 mg dose of an American ginseng extract (called Cereboost) had increased working memory, peaking within three hours of the dose. The findings were limited by the small size of the study (52 adults) and the lack of a control group (meaning a group given a sham placebo).8
A 2022 study involving 61 adults showed longer-lasting improvements in working memory after taking 200 mg of Cereboost daily for two weeks. For this study, a control group was included, but the findings were limited by the fact that the research was funded by the manufacturer, Naturex SA.9
An unrelated study published in 2012 reported that an American ginseng extract taken twice daily for four weeks improved the working memory of 32 people with schizophrenia compared to a matched set of adults given a placebo.10
A 2014 review of 16 ginseng trials concluded that the fasting blood sugar was modestly lowered by taking ginseng. Three of the 16 studies looked at American ginseng specifically.11
A 2019 study involving 24 adults with well-controlled type 2 diabetes showed that a 3,000 mg dose of American ginseng taken daily helped control blood sugar. At the end of the eight-week study, the people given American ginseng had lower hemoglobin A1C levels, fasting blood sugar, and systolic blood pressure than those given a placebo.12
The findings were limited by the fact that the participants' blood sugar was already controlled by medications. At present, there is no evidence that ginseng is able to manage diabetes on its own.
According to a 2017 review of studies in the Journal of Complementary and Alternative Medicine, American ginseng may offer protection against common viral respiratory infections like colds and flu.13 This supported earlier research in which American ginseng appeared to reduce the risk and duration of colds and flu in older adults with weakened immune systems.14
A 2020 analysis published in Complementary Therapy and Medicine suggested that American ginseng may help prevent or treat seasonal respiratory infections in some people, but that the evidence wasn't strong enough to offer a clear conclusion.15
Preliminary studies have investigated American ginseng for the following conditions:1
