The plant is poisonous.
Application
Hellebore has been used as a medicine in the Middle Ages, but monks believed it was dangerous to use because the effects were difficult to predict. Hellebore was most often used to treat epilepsy and depression, as well as as a strong laxative. Overdose can cause cardiac arrest.
Externally, hellebore has been used to treat scabies, scabies, and other skin conditions. Hellebore has also been used to combat lice and fleas.
Hellebore is used in homeopathic remedies for headaches, mental imbalances and cramps.
Hellebore has been widely used to treat diseases in livestock. Cattle diseases in particular were treated with Hellebore. Up until 1920, Hellebore was used to treat foot-and-mouth disease.
Ingredients
Various cardiac glycosides, aconitic acid, glycosides and bitter substances.

Helleborus foetidus L.
Photo of page in Joachim Burser's herbarium.