If you are being treated with any of the following medications, you should not use ginseng without first talking to your health care provider:
Anti-Diabetic medications -- American ginseng may lower blood sugar levels. Therefore, this herb may interfere with the effectiveness of blood sugar lowering prescription medications. Talk with your health care provider before using American ginseng if you are taking medicines for diabetes, including insulin and oral hypoglycemic agents.
Blood thinning medications -- Some reports have indicated that ginsenosides may possibly decrease the effectiveness of warfarin, a blood-thinning medication. In addition, ginsenosides may inhibit platelet activity and, therefore, should probably not be used with aspirin either.
Psychiatric medications -- American ginseng may exaggerate the effects of medications used in various psychiatric disorders, so they should not be taken together. There have been reports of a possible interaction between Asian ginseng and the antidepressant medication, phenelzine (which belongs to a class known as monoamine oxidase inhibitors, resulting in symptoms ranging from manic-like episodes to headache and tremulousness
Morphine -- Asian ginseng may block the painkilling effects of morphine.