The effect of red ginseng extract on the disposition of ethanol was studied in male Fischer 344 rats. Blood was drawn from the tail vein before and at 0.5, 1, 2, 3, 4, and 5 hours after dosing rats orally with aqueous ginseng (200mg/kg), or an equivalent volume of water, followed immediately by 50% ethanol orally (3.2g/kg) or intraperitoneally (1.5g/kg). When the ethanol was administered orally, the mean area under the plasma concentration-time curve (0→5 h) of ethanol was 21.0% less in the ginseng-treated rats than in the control rats. When the ethanol was administered intraperitoneally, there was no significant difference between ginseng-treated and control rats in area under the plasma concentration-time curve. The results show that plasma levels of ethanol are lower when the ethanol is administered orally with ginseng than when it is administered alone, but that orally administered ginseng has no effect on plasma levels of ethanol administered intraperitoneally.