Arnica is a plant with small yellow or orange flowers and grows perennially throughout most of Europe. While the oral form of arnica is usually not recommended, the topical version is frequently used by many people. As of 2011, people have used arnica for bruising for hundreds of years; however, research in the past few years put the effectiveness of the homeopathic remedy to question. Many of the studies done showed that arnica had little to no effect on healing bruises or minimizing swelling, and some research was inconclusive. Only a few trial results showed positive outcomes with homeopathic arnica use.
The doctors in one study split a group of post-surgery patients into three groups. Two groups took either a high or low dose or arnica regularly, while the last took the placebo. Results of this study showed no difference among any of the patients. Several homeopathic-friendly doctors argue that arnica for bruising works best in smaller doses and thus consider this particular trial invalid.
Results of another trial that supposedly used less arnica on laser induced bruises yielded the same results. There was no noticed effect on the bruises treated with arnica. This particular trial applied the arnica before and after the induced bruising, which further questions the effectiveness of arnica for the prevention of bruises as well. The trial did not measure other supposed benefits associated with arnica for bruising beyond the physical appearance, such as reduction in swelling or pain.
One study from 2010 did show supportive evidence concerning the effectiveness of arnica for bruising. In this particular trial, each patient had several laser induced bruises on his or her arm, and each bruise had a different topical ointment applied. The results concluded that a 20 percent concentration of arnica in a topical solution helped to reduce bruising compared to retinol, petroleum and vitamin K. As of 2011, there are no other studies with results as supportive as this trial.
Despite the lack of scientific evidence supporting the effectiveness of arnica for bruising, several healthcare professionals who are advocates of homeopathic remedies still recommend arnica use for bruises. It is generally agreed upon by this group that regular, small doses of arnica ointment will benefit people suffering from bruises. Overuse, however, may result in burning of the skin, peeling or itching. Contact dermatitis may also occur in people with sensitive skin.