Arnica

Medically Reviewed by Melinda Ratini, MS, DO on September 05, 2023
3 min read

 

Arnica is an herb that grows in Europe and the U.S. It’s often used as a skin treatment for bruises, aches, and pains.

Early studies of topical homeopathic arnica gels and ointments for arthritis symptoms of the hand and knee -- like pain and swelling -- have been positive. So far, research is mixed on whether arnica skin treatments can help ease muscle pain.

If eaten, the actual herb is toxic to the liver and can be fatal. However, some oral supplements contain highly diluted arnica. These are considered homeopathic treatments. These low-dose arnica tablets have been studied for muscle pain, diabetic eye damage, and swelling and pain after surgery. More research needs to be done to establish effectiveness for those problems. 

Because of the risks of pure arnica, the FDA classifies it as an unsafe herb. Doctors who practice complementary medicine generally advise against using arnica in any form other than in a highly diluted homeopathic form.

Arnica is usually taken by mouth, or through ointments and fresh plant gel applied on the skin. 

Homeopathic treatments are usually individualized based on the specific symptoms of the patient.

For topical treatment of conditions such as osteoarthritis, it is suggested that you should use an arnica gel product and rub it into the affected joints two to three times daily for 3 weeks.

Make sure you only use diluted homeopathic preparations because pure arnica can be toxic to your liver if taken internally. While there appear to be no risks to using homeopathic arnica, it is important to consult your doctor before taking it.

There are no natural food sources of arnica besides the plant itself. Arnica is used as a flavoring in some food products.

Arnica can come in tablets, tinctures, ointments, gels, and mouth rinses. Like any supplement, keep arnica in a cool, dry place, away from humidity and direct sunlight.

  • Side effects. Pure arnica herb is poisonous. Homeopathic doses are generally considered safe to use. Homeopathic arnica creams or gels can cause burning and skin irritation.
  • Risks. Always talk to a doctor before using arnica. When swallowed, pure arnica can cause rapid heartbeat, gastrointestinal problems, kidney and liver damage, coma, and death. Don’t use arnica topically on broken or sensitive skin.
  • Interactions. If you take any medicines regularly, discuss them with your doctor before you start using homeopathic arnica supplements. They could interact with drugs like painkillers, steroids, blood pressure drugs, blood thinners, and herbs like ginkgo biloba, garlic, and saw palmetto.

Given the lack of evidence about its safety, arnica is not recommended for children and is considered unsafe for women who are pregnant or breastfeeding.