Does Arnica Help to Relieve Pain?

Managing pain isn't easy. If you are dealing with pain, you may have heard about arnica, a homeopathic remedy that has been in use for centuries.

Arnica comes from the perennial Arnica montana. While the herb is considered toxic when ingested, creams, gels, and ointments derived from arnica are sometimes used topically for muscle pain and aching, bruising, osteoarthritis, and inflammation. Homeopathic remedies containing arnica are extremely diluted through a process that results in little or no detectable active ingredient.

One of the most common uses of arnica is in the treatment of bruising and pain. An arnica-based gel, cream, ointment, or salve is topically applied to promote healing and soothing of the skin or the homeopathic form is taken orally. Arnica gel is also touted as a means of relieving muscle soreness and sprain-related pain.

Related: 6 Herbs for Pain Relief

Several studies have found arnica to be no more effective than a placebo in relieving pain, swelling, and bruising. Still, other research suggests that arnica may be useful in certain situations. 

One of the most common uses for arnica is for bruising after surgery. The evidence is inconclusive on whether it can help. In a 2016 report published in Dermatologic Surgery for instance, researchers reviewed previously published studies examining the use of oral homeopathic arnica, topical arnica, or oral bromelain in the prevention or treatment of post-procedure bruising or swelling. Although four out of 13 clinical trials reported improvement with arnica, the report's authors concluded there was insufficient data to support the use of either arnica or bromelain. 

A study published in Plastic and Reconstructive Surgery in 2016 examined the use of an arnica cream, a mucopolysaccharide polysulfate cream, or no treatment in 118 people who had undergone rhinoplasty. After evaluating the people on days 2, 5, 7, and 10, researchers found that people who used either cream had less bruising and less swelling during evaluations than those who had no treatment.

In a research review published in the Cochrane Database of Systematic Reviews in 2013, for instance, scientists analyzed seven previously published clinical trials focusing on topical herbal therapies in people with osteoarthritis.

In their conclusion, the review's authors state that "Arnica gel probably improves symptoms as effectively as a gel containing non-steroidal anti-inflammatory drug, but with no better (and possibly worse) adverse event profile".

Arnica should never be taken internally, due to side effects that can include drowsiness, stomach pain, diarrhea, rapid heartbeat, shortness of breath, coma, or even death. While arnica can be toxic when ingested, homeopathic arnica products are extremely diluted forms that are generally considered safe. However, some homeopathic forms of arnica, particularly topical products, may contain detectable levels of arnica.

In some cases, topical use of arnica can cause skin irritation, itching, blisters, and other allergy-related problems. Be careful not to use topical arnica on broken or sensitive skin or use it for an extended period of time.

If you are pregnant, breastfeeding, or are about to have surgery, consult your doctor before using arnica.

Arnica products may cause allergic reactions in people who are sensitive to ragweed and other members of the Asteraceae/Compositae family (such as chrysanthemums, marigolds, sunflowers, and daisies)

It's important to keep in mind that self-treating a condition and avoiding or delaying standard care may have serious consequences.

Homeopathic arnica, as well as arnica gels, ointments, and creams, can be purchased at some health food stores or drug stores.

As with most homeopathic remedies, the evidence is still very limited. If you're still considering using arnica, talk with your healthcare provider first to weigh the pros and cons and discuss whether it's appropriate for you.