American Ginseng and Breast Cancer
Key Takeaways:
Studies suggest that American ginseng reduces fatigue in people getting cancer treatment.
There isn’t enough evidence in people to know if American ginseng can reduce other side effects of treatment or help prevent or treat cancer.
American ginseng is generally safe, but people with estrogen receptor-positive breast cancer should avoid certain ginseng preparations.
You shouldn't take ginseng if you take blood thinners because it can raise the risk of bleeding.
American ginseng is an herbal supplement used in traditional Chinese medicine. Recently, people across the world have started using the root of American ginseng for cancer. You can take it as a capsule, pill, liquid extract, or powder.
There are a few varieties of the ginseng plant. American ginseng (scientific name Panax quinquefolius) and Asian/Chinese ginseng (scientific name Panax ginseng) are the two most common varieties used for health.
American ginseng can’t cure cancer, but it may be used as a complementary therapy.
What the research shows
Several large studies have tested the effects of American ginseng on cancer-related fatigue in people.
But fewer studies have looked at American ginseng’s ability to fight cancer in people. How American ginseng is prepared — for example, as a liquid extract or a capsule — can change what it contains and its effects. But most of the studies done so far do not specify which preparation was used, so it’s hard to say which are effective (and for what).
Cancer treatment side effects
The 2025 guidelines on managing fatigue from the American Society of Clinical Oncology and Society for Integrative Oncology state that American ginseng may be recommended for people undergoing cancer treatment. This recommendation is based on studies that found people who took 2,000 mg of American ginseng a day for at least four to eight weeks had more energy during cancer treatment than those who didn’t take the supplement.
There’s not enough data to know if American ginseng improves fatigue after treatment is done. One study of people who had finished treatment found that American ginseng did not help with fatigue.
American ginseng may ease other side effects of cancer and treatment. For example, a 2006 study found that taking ginseng of any variety may be linked to a better quality of life, especially well-being, in people with breast cancer. And a small study found that it protects a type of white blood cell that fights cancer and infection from radiation therapy damage.
Cancer risk
American ginseng may lower the risk of some cancers, but the evidence is mixed. Many studies that look at the link to cancer risk also don’t separate out American and Chinese ginseng, or they only look at Chinese ginseng.
A 2015 review found that taking ginseng in general lowers overall cancer risk by 16%. A 2023 study didn’t find a link between ginseng and overall cancer risk, but people who took ginseng had a higher risk of liver and thyroid cancer and a lower risk of non-Hodgkin’s lymphoma and cancers of the blood and lymph systems.
Another study found that people with breast cancer who had been taking ginseng of any variety before a diagnosis were less likely to have the cancer come back (recur).
Cell and animal studies
Studies in cells and animals are an important early step in research. But you can’t draw conclusions about how things will work in people based on these studies. For example, adding American ginseng to cells in a lab dish can’t tell researchers how the supplement will be absorbed or broken down in your body. And cancer can behave differently in a mouse than it behaves in a person. These studies are valuable, though, because they help researchers find promising leads and decide if they should test these leads in people.
Lab studies suggest that some preparations of American ginseng can kill breast cancer cells, limit breast cancer cell growth, stop tumors from growing blood vessels that feed them, reduce cancer cells’ resistance to drugs, and boost the immune system. Animal studies suggest that American ginseng berry extract may reduce treatment side effects like nausea and vomiting and protect the kidneys from toxic chemotherapy side effects. Some preparations of American ginseng may also protect red blood cells from chemo side effects.
Lab studies also show that ginseng may have different effects when it’s prepared with methanol. Some lab studies suggest that ginsenosides — the main components of ginseng that give it health benefits — can act like estrogen and help estrogen receptor-positive breast cancer grow when ginseng is prepared with methanol. However, this effect has not been confirmed in people. Other lab studies show that American ginseng does the opposite and stops estrogen receptor-positive breast cancer cell growth when it is not prepared with methanol. Out of an abundance of caution, experts recommend that people with estrogen receptor-positive cancer look for preparations that are alcohol-free.
Other uses
Early research suggests that some American ginseng preparations may improve memory, brain health, heart health, diabetes, obesity, and even prevent or shorten the common cold. It also acts like an antioxidant to lower oxidative stress, which is an imbalance in the body’s molecules. Oxidative stress increases the risk of cancer, heart disease, kidney disease, and neurological diseases.
Safety, risks, and side effects
American ginseng does not usually cause side effects. Experts recommend taking 2,000 mg per day for cancer-related fatigue. For other uses, people commonly take 200 to 400 mg twice per day.
Always check with your doctor before starting a new supplement. Do not take ginseng if you take blood thinners because it can raise your risk of bleeding. It should also be used with caution if you take diabetes medication, immunosuppressants, and monoamine oxidase inhibitors (MAOIs).
So should you take American ginseng?
American ginseng might help ease fatigue during cancer treatment. More studies in people are needed to understand if it can help prevent or fight cancer or reduce other side effects. Taking American ginseng is generally safe, so people with cancer may consider taking it as a complementary therapy — but be sure to talk to your doctor before taking American ginseng supplements. People with estrogen receptor-positive breast cancer should look for alcohol-free ginseng preparations.