Clinical trial, with positive findings,  on 48 patients with bruising and swelling following plastic surgery on  the nose, treated at a university hospital in the USA. Approximately one  third of the patients were randomly allocated to receive homeopathic  Arnica, another third received steroids, and the others received no  treatment. They were not told which treatment group they were in. After 8  days, there were no differences in swelling between the three groups;  the extent and intensity of bruising was least in the Arnica group and  most in the steroid group.

PubMed Link