Tormentil root (Potentilla tormentilla) is a treatment for diarrhea long used in many European countries. Potentilla extract composition includes 30 to 40% of tannins, saponin, and other components. Several manufacturers in Europe market tormentil root extract for treatment of diarrhea. Tannins are known to have an antisecretory effect. In addition, Tormentil root has anti-inflammatory (26-27), immunostimulating (28), and potentially antiviral effects (29).
The effectiveness of tormentil root was evaluated in a clinical study conducted in children diagnosed with rotavirus diarrhea. The study demonstrated that tormentil root administered by mouth at the dose of 1.5 milligram per kilogram of a child’s weight reduced the duration of diarrhea and associated fluid losses by approximately 50%, without any side effects. Some parents of the children whom participated in the study reported total cessation of diarrhea in their children following the administration of a single dose of tormentil root extract (30). A study on adults with ulcerative colitis, a debilitating, hard to treat disease, which manifests in frequent bouts of severe diarrhea with intestinal bleeding, showed marked improvement following administration of tormentil root (34).
Tormentil Root is Safe
Tormentil root is one of the safest herbs and has no known toxicity or side effects. Tormentil root does not interact with other herbs or drugs (31). The American Herbal Product Association placed tormentil root in Class I (The Safest Herbs): herbs that can be safely consumed when used appropriately (32). An animal study of tormentil root toxicity demonstrated that oral administration of a single dose of 2,500/mg/kg of tormentil root extract to rats, and 6,800 mg/kg to mice caused no toxic effects. These doses were several thousand times higher than doses routinely used in humans to treat diarrhea (33).