Arnica is a prescription drug that is used to relieve the irritation caused by soreness and minor bruising of the skin. The drug is a counterirritant. Arnica is prescribed for external use only.
The homeopathic remedy Arnica is used to treat pain, particularly bruising and muscle aches and stiffness. It is available in pill form or as an ingredient in homeopathic creams or ointments meant to treat muscle pain. Like other homeopathic remedies, its active ingredients are greatly diluted.
Arnica montana is a flowering plant that is used as a non-medicinal remedy for pain and bruising. Other uses include reducing swelling and alleviating joint pain. It is used topically, and studies have shown it is quite safe when used for two weeks or less in homeopathic doses, according to the University of Maryland Medical Center. However, prolonged use or taking too much can cause serious problems. It is best to consult a professional before using arnica montana.