While arnica has a long history of use in traditional medicine and homeopathy for diverse conditions (e.g., pain, contusion, wounds, bruising, rheumatism, arthritis in general, and inflammation), the scientific evidence supporting its efficacy remains limited.[1][2]
In regard to post-operative pain, one meta-analysis assessing homeopathic arnica’s effect on pain, bleeding, swelling, and discomfort after minor surgeries (e.g., carpal tunnel surgery, oral-facial, or dental surgery) found no significant effect compared to placebo or other interventions.[3]
Arnica is also used topically to treat skin bruising. While the evidence may not align with the marketing claims, one RCT demonstrated that a topical application of arnica was more effective than petrolatum ointment or a mixture of 1% vitamin K and 0.3% retinol in reducing laser-induced skin bruising.[4] However, larger studies are essential to validate and establish the consistency of this effect.
Regarding arnica’s effectiveness in relieving osteoarthritis symptoms, positive outcomes have been observed, particularly for hand and knee osteoarthritis.[5][6] For more detailed information, please refer to the question “Is arnica effective in relieving symptoms of osteoarthritis?”.