A small number of people experience nausea and/or vomiting when using boneset. The fresh plant, however, is more likely to cause this than the dried herb. Although potentially liver-damaging chemicals, called pyrrolizidine alkaloids, are found in some plants similar to boneset, the levels in boneset are minimal. There are no known reports of liver damage from taking boneset. Nevertheless, patients with liver disease should avoid boneset, and no one should take it consistently for longer than six months. Boneset is not recommended during pregnancy or breast-feeding. Boneset should not be used when a high fever (over 102 degrees F) is present.