Willow bark is the bark from several varieties of the willow tree, including white willow or European willow, black willow or pussy willow, crack willow, purple willow, and others. The bark is used to make medicine.
Salicin, the active ingredient in willow bark, seems to have contributed to the death of the composer, Ludwig von Beethoven. Apparently, Beethoven ingested large amounts of salicin before he died. His autopsy report is the first recorded case of a particular type of kidney damage that can be caused by salicin.
How does it work?
Willow bark contains a chemical called salicin that is similar to aspirin.