What is arnica (Arnica montana)-topical, and how does it work (mechanism of action)?

Arnica montana is a homeopathic topical pain relief agent. Its mechanism of action is not well known. Arnica preparations have shown wound healing, antiseptic, anti-inflammatory, and pain relieving properties. Arnica’s actions may be due to two chemicals called helenalin and dihyrdohelenalin. These chemicals may modify the action of immune cells, kill bacteria, reduce the activity of chemicals and blood cells that cause inflammation, and kill cancer cells.

What brand names are available for arnica (Arnica montana)-topical?

Arnicare, Arniflora

Is arnica (Arnica montana)-topical available as a generic drug?


Do I need a prescription for arnica (Arnica montana)-topical?


What are the side effects of arnica (Arnica montana)-topical?

Arnica should not be applied to open wounds or mucous membranes. Arnica also may give mild odor when applied. Undiluted oral forms are considered unsafe and have been reported to cause the following side effects:

Pure arnica is considered an unsafe herb by the FDA.

What is the dosage for arnica (Arnica montana)-topical?

Topical Cream or Gel

  • Adults and children 2 years of age and older: Apply a thin layer to affected area(s) as soon as possible after injury. Repeat 3 to 4 times a day or as needed. Avoid contact with eyes and open wounds.
  • Children under 2 years of age: Consult a doctor.


Adults and children 2 years of age and older: at the onset of symptoms, dissolve 2 tablets in the mouth or in 1 tablespoon of water and repeat every hour for 2 more hrs. Then dissolve 2 tablets in the mouth every 6 hrs.

Which drugs or supplements interact with arnica (Arnica montana)-topical?

There are no significant drug interactions, when using topical forms of arnica. Arnica may increase the effect of anticoagulants and other drugs that increase the risk of bleeding when taken orally.

Chronic Pain Syndrome: Treatment and Management for CPS

Is arnica (Arnica montana)-topical safe to take if I’m pregnant or breastfeeding?

There are no adequate studies done on arnica to determine safe and effective use in pregnant women. It is considered unsafe during pregnancy. Arnica has been used to cause abortions.

It is not known whether arnica enters breast milk; therefore, it is best to be cautious before using it in nursing mothers.

What else should I know about arnica (Arnica montana)-topical?

What preparations of arnica (Arnica montana)-topical are available?

Quick dissolving tablets; Ointment: 4%; Cream: 7%; Gel 7%, 8%

How should I keep arnica (Arnica montana)-topical stored?

Store Arnica Montana at room temperature between 20 C to 25 C (68 F to 77 F).

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Medically Reviewed on 3/4/2019


Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


FDA Poisonous Plant Database.