Early studies of topical homeopathic arnica gels and ointments for arthritis symptoms of the hand and knee -- like pain and swelling -- have been positive. So far, research is mixed on whether arnica skin treatments can help ease muscle pain.
If eaten, the actual herb is toxic to the liver and can be fatal. However, some oral supplements contain highly diluted arnica. These are considered homeopathic treatments. These low-dose arnica tablets are safe to use and have been studied for muscle pain, diabetic eye damage, and swelling and pain after surgery. More research needs to be done to establish effectiveness for those problems. A study of children with cancer, however, found that homeopathic low-dose arnica may help reduce mouth ulcers related to chemotherapy.