If you are currently being treated with any of the following medications, you should not use ginseng without first talking to your healthcare provider:

Blood Thinning Medications
There have been reports that ginseng may possibly decrease the effectiveness of the blood-thinning medication, warfarin. In addition, ginseng may inhibit platelet activity and, therefore, should probably not be used with aspirin either.

Caffeine
While taking ginseng, it is wise to avoid caffeine or other substances that stimulate the central nervous system because the ginseng may increase their effects, possibly causing nervousness, sweating, insomnia, or irregular heartbeat.

Haloperidol
Ginseng may exaggerate the effects of this anti-psychotic medication, so they should not be taken together.

Morphine
Ginseng may block the pain killing effects of morphine.

Phenelzine and other MAOIs for Depression
There have been reports of a possible interaction between ginseng and the antidepressant medication, phenelzine (which belongs to a class known as monoamine oxidase inhibitors [MAOIs]), resulting in symptoms ranging from manic-like episodes to headache and tremulousness.