I was taught originally that Arnica, or A. montana, is not particularly safe to eat. After my researching the most recent medical studies on PubMed, I now have a different opinion.
Is Arnica toxic? The health benefits of A. montana are derived from sesquiterpene lactones, a class of chemical compounds commonly found in many plants throughout the world. Our research into the potential effects of Arnica montana led us to the chemical Helenalin.