It found that, when compared to a placebo, arnica lotion actually increased leg pain 24 hours after atypical muscle use. However, a 2016 review of studies found that arnica is both safe and effective at easing pain after surgery.

Does arnica really work for bruising?

Arnica stimulates your body's natural healing process, facilitating blood flow through the area, which helps to alleviate pain, reduce swelling, and reabsorb bruising. As long as your skin isn't broken, you can apply Arnica topically in a cream or gel form.

Does arnica really work for pain?

The active chemicals in arnica may reduce swelling, decrease pain, and act as antibiotics. But arnica can be unsafe when taken by mouth unless it's used in homeopathic dilutions. Homeopathic products contain extreme dilutions of the active chemicals. People most commonly use arnica for pain caused by osteoarthritis.