Ginseng is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must provide the FDA with results of detailed testing showing their product is safe and effective before the drug is approved for sale), the companies that make supplements do not have to show evidence of safety or health benefits to the FDA before selling their products. Supplement products without any reliable scientific evidence of health benefits may still be sold as long as the companies selling them do not claim the supplements can prevent, treat, or cure any specific disease. So if a company is making claims that their product has beneficial medicinal effects such as boosting oxygen intake, then not only is that BS, it is illegal.
Herbal supplements also may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). There is no regulation of the manufacturing process or safety of these product. Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements.
Never take any kind of supplements while in chemo without your oncologists specific approval.