Gentian root and other highly bitter plants have been used for centuries in Europe as digestive aids (the well-known Swedish bitters often contain gentian). Other folk uses included topical use on skin tumors, decreasing fevers, and treatment of diarrhea. Its ability to increase digestive function, including production of stomach acid, has been validated in modern times.
Gentian root contains some of the most bitter substances known, particularly the glycosides gentiopicrin and amarogentin. The taste of these can be detected even when diluted 50,000 times. Besides stimulating secretion of saliva in the mouth and hydrochloric acid in the stomach, gentiopicrin may protect the liver.
Gentian root is also considered useful for poor appetite and indigestion according to the German government’s Commission E monograph.