Just learned something new...
Ginseng cultivated in Korea is classified into three types, depending on how it is processed: fresh ginseng (less than 4 years old), white ginseng (4–6 years old and dried after peeling), and red ginseng (harvested when 6 years old, steamed and dried)
Apparently red ginseng and white ginseng are the same plant, and age/processing are the only determinants. So white ginseng may well be effective too.