Arnica (Arnica montana) is very popular—Germany alone has manufactured more than 100 drug preparations containing this herb. Applied topically as a cream, ointment, liniment, salve, or tincture, arnica has been used by both Europeans and Native Americans to soothe muscle aches, reduce inflammation, and heal wounds. While arnica has also been used internally as an herbal remedy for certain heart disorders, it should only be used in this way under the supervision of a healthcare provider. In fact, arnica in herbal form is primarily restricted to topical (external) use because it can cause serious side effects when it is used internally.

Arnica is a perennial that grows to a height of 1 to 2 feet with yellow-orange flowers similar to daisies. Stems are round and hairy, ending in one to three flower stalks, with flowers 2 to 3 inches across. Leaves are bright green; the upper surfaces are toothed and slightly hairy while lower leaves have rounded tips. It is native to the mountains of Europe and Siberia, and cultivated in North America.

Fresh or dried flower heads are used in medicinal preparations.

• Arnica is used topically for a wide range of conditions including bruises, sprains, muscle aches, wound healing, acne, superficial phlebitis, rheumatic pain, inflammation from insect bites, and swelling due to fractures.
• An experienced clinician may recommend arnica as an herbal remedy for senile heart, angina, or coronary artery disease.
• Homeopathic preparations are also used to treat sore muscles, bruises, and other conditions associated with overexertion or trauma. Homeopathic doses are very dilute and generally considered safe for internal use when taken in accordance with the directions on the product labeling.

Many topical preparations containing arnica are available commercially. Arnica is most commonly prepared as a tincture, which can also be used as the base for creams, ointments, compresses, and poultices. Arnica oil may also be used in topical preparations.

As an internal herbal remedy, arnica may be taken as a tea.

A number of homeopathic remedies are available in pill or injectable forms.

Topical preparations of arnica may be prepared as follows:

• Tincture: a 1:10 tincture prepared with 70% ethanol

• Creams and ointments: 20 to 25% tincture or a maximum of 15% arnica oil made from one part dried arnica flower head and five parts vegetable oil

• Compresses: tincture diluted 3 to 10 times with water

• Poultices: tincture diluted 3 to 10 times with water

• Mouthwash: tincture diluted 10 times with water (should not be swallowed)

For topical use of commercially prepared products, follow the directions on the product label or consult a qualified practitioner.

Arnica should not be taken internally as an herbal tea except under direct supervision of a healthcare professional, as side effects may be severe (see Precautions).

Homeopathic products should be used in accordance with the directions on the label or a homeopathic practitioner should be consulted. Healthcare professionals will administer injectable homeopathic preparations in a clinical setting.

Used topically, arnica is generally safe. However, prolonged use may irritate the skin, causing eczema, peeling, blisters, or other skin conditions. Arnica should not be used on broken skin, such as leg ulcers. Also, people who are hypersensitive or allergic to the herb should avoid it.

Arnica is rarely used as an internal herbal remedy because it can cause dizziness, tremors, and heart irregularities. It may also irritate mucous membranes and cause vomiting. Arnica should only be used internally under the supervision of a professional clinician who understands the risks and benefits of this herb. Homeopathic remedies, which use minute amounts of their herbal ingredients, do not generally carry these risks.

If you are pregnant or breastfeeding, you should consult with your physician before taking any medication, including herbs.

To date there are no known reports in the literature of any noteworthy interactions (either positive or negative) between arnica and conventional medications.

Bisset NG, ed. Herbal Drugs and Phytopharmaceuticals: A Handbook for Practice on a Scientific Basis. Boca Raton, Fla: CRC Press; 1994.

Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, Mass: Integrative Medicine Communications; 1998.

Blumenthal M, Goldberg A, Brinckmann J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, Mass: Integrative Medicine Communications; 2000.

Conforti A, Bertani S, Metelmann H, Chirumbolo S, Lussignoli S, Bellavite P. Experimental studies of the anti-inflammatory activity of a homeopathic preparation. Biol Ther. 1997;15(1):28-31.

Gruenwald J, Brendler T, Jaenicke C, et al., eds. PDR for Herbal Medicine. Montvale, NJ: Medical Economics Company; 1998.

Kowalchik C, Hylton W. Rodale's Illustrated Encyclopedia of Herbs. Emmaus, Pa: Rodale Press; 1997.

Lussignoli S, Bertani S, Metelmann H, Bellavite P, Conforti A. Effect of Traumeel S, a homeopathic formulation, on blood-induced inflammation in rats. Complement Ther Med. 1999;7(4):225-230.

Lyss G, Schmidt TJ, Merfort I, Pahl HL. Helenalin, an anti-inflammatory sesquiterpene lactone from Arnica, selectively inhibits transcription factor NF-kappaB. Biol Chem. 1997;378(9): 951-961.

Mills S, Bone K. Principles and Practice of Phytotherapy. Edinburgh, Scotland: Churchill Livingstone; 1999.

Robbers J, Tyler V. Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: The Haworth Herbal Press; 1999.

Schmidt TJ, Bomme U, Alfermann AW. Sesquiterpene lactone content in leaves of in vitro and field cultivated Arnica montana. Planta Med. 1998; 64(3):268-270.

Schulz V, Hänsel R, Tyler V. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. 3rd ed. Berlin: Springer-Verlag; 1998.

Tveiten D, Bruset S, Borchgrevink CF, Norseth J. Effects of the homeopathic remedy Arnica D30 on marathon runners: a randomized, double blind study during the 1995 Oslo marathon. Complement Ther Med. 1998;6(2):71-74.

Vickers AJ, Fisher P, Smith C, Wyllie SE, Rees R. Homeopathic Arnica 30X is ineffective for muscle soreness after long-distance running: a randomized, double-blind, placebo-controlled trial. Clin J Pain. 1998;14(3):227-231.

Weiss R, Fintelmann V. Herbal Medicine. Stuttgart, Germany: Thieme; 2000.

Wijnsma R, Woerdenbag HJ, Busse W. The importance of Arnica-species in phytomedicine. Z Phytother. 1995;16(1):48-62.