Uses of Arnica

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate. The effectiveness ratings for ARNICA are as follows:

Possibly effective for…

  • Osteoarthritis. Early research shows that using a gel product (A. Vogel Arnica Gel, Bioforce AG) twice daily for 3 weeks reduces pain and stiffness and improves function in people with osteoarthritis in the hand or knee. Other research shows that using the same gel works as well as the painkiller ibuprofen in reducing pain and improving function in the hands.

Possibly ineffective for…

  • Reducing pain, swelling, and complications of wisdom tooth removal. In most research, taking arnica by mouth does not seem to reduce pain, swelling, or complications after wisdom tooth removal. One early study suggests that taking six doses of homeopathic arnica 30C might reduce pain, but not bleeding.

Insufficient evidence to rate effectiveness for…

  • Bleeding. Early research suggests that placing 5 drops of a homeopathic preparation under the tongue three times per day might reduce blood loss following surgery for breast cancer. But problems with the design of this study limit the reliability of these results.
  • Bruises. Most research shows that taking homeopathic arnica by mouth or applying arnica to the skin does not reduce bruising after surgery. But several conflicting studies show benefit.
  • Vision problems due to diabetes. Early research shows that taking homeopathic arnica by mouth for 6 months reduces vision problems in people with vision loss due to diabetes.
  • Muscle soreness after exercise. Most research shows that taking homeopathic preparations by mouth does not prevent muscle soreness after exercise. It’s unclear if applying arnica to the skin after exercise prevents muscle soreness. Some research shows benefit. But other research shows that applying it to the skin can worsen muscle pain after exercise.
  • Swelling after surgery. The effects on swelling when applied to the skin after surgery are unclear. Some research shows a slight benefit. But other research shows that applying arnica doesn’t reduce swelling after surgery.
  • Pain after surgery. Most research shows that taking homeopathic arnica by mouth slightly reduces pain after surgery. In some cases, homeopathic arnica has been used together with an ointment from 72 hours after surgery for 2 weeks. But not all research has been positive.
  • Stroke. Early research shows that taking one tablet of homeopathic arnica 30C under the tongue every 2 hours for six doses does not benefit people who have had a stroke.
  • Acne.
  • Chapped lips.
  • Insect bites.
  • Painful, swollen veins near the surface of the skin.
  • Sore throats.
  • Other conditions.

More evidence is needed to rate the effectiveness of arnica for these uses.

Side Effects of Arnica

Arnica is POSSIBLY SAFE when taken by mouth in the amounts commonly found in food or when applied to unbroken skin short-term. The Canadian government, however, is concerned enough about the safety to prohibit its use as a food ingredient.

Amounts that are larger than the amount found in food are LIKELY UNSAFE when taken by mouth. In fact, it is considered poisonous and has caused death. When taken by mouth it can also cause irritation of the mouth and throat, stomach pain, vomiting, diarrhea, skin rashes, shortness of breath, a fast heartbeat, an increase in blood pressure, heart damage, organ failure, increased bleeding, coma, and death.

Arnica is often listed as an ingredient in homeopathic products; however, these products are usually so dilute that they contain little or no detectable amounts.

Warnings & Precautions

  • Pregnancy and breast-feeding: Don’t take arnica by mouth or apply it to the skin if you are pregnant or breast-feeding. It is considered LIKELY UNSAFE.
  • Allergy to ragweed and related plants: Arnica may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, be sure to check with your healthcare provider before applying them to your skin. Do not take arnica by mouth.
  • Broken skin: Don’t apply arnica to damaged or broken skin. Too much could be absorbed.
  • Digestion problems: Arnica can irritate the digestive system. Don’t take it if you have irritable bowel syndrome (IBS), ulcers, Crohn’s disease, or other stomach or intestinal conditions.
  • Fast heart rate: Arnica might increase your heart rate. Don’t take it if you have a fast heart rate.
  • High blood pressure: Arnica might increase blood pressure. Don’t take arnica if you have high blood pressure.
  • Surgery: Arnica might cause extra bleeding during and after surgery. Stop using it at least 2 weeks before a scheduled surgery.

Dosage Of Arnica

The following dose has been studied in scientific research:


For osteoarthritis: A gel product with a 50 gram/100-gram ratio (A. Vogel Arnica Gel, Bioforce AG) has been rubbed into the affected joints two to three times daily for 3 weeks.


Consult your doctor or pharmacist


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.