Find out more about arnica gel and if this plant-derived pain remedy really works.

By Isadora Baum
August 23, 2018

You’ve probably heard of arnica gel, a plant-based remedy applied to the skin that supposedly eases pain and relaxes sore muscles, among other uses. Arnica gel and a similar product, arnica cream, are available over the counter and can be bought online, at drugstore chains, or your local organic or natural grocery store.

Because it's a homeopathic remedy, you might not be sure that it's safe and really works. "Homeopathic products are regulated as drugs under the Federal Food, Drug, and Cosmetic Act (FDCA)," states the National Institutes of Health's National Center for Complementary and Integrative Health. "However, under current agency policy, the FDA does not evaluate them for safety or effectiveness."

While some users have given arnica gel rave reviews online, it’s a good idea to get an overview of what it is, which conditions users claim it can treat, and what science says about it before trying it. Here’s what you should know about arnica gel before dabbing it on your skin.

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What is arnica gel?

Arnical gel comes from the flowers of the arnica plant. “Arnica is an herb that mostly grows in mountain regions in Europe as well as in East Asia, Canada, and the northern U.S.," says Sonia Batra, MD, a dermatologist and co-host of the TV show The Doctors. "People use the plant’s flowers to decrease inflammation from ailments such as a sore throat, insect bites, swelling, bruising, muscle pain, arthritis, and other general pain.”

Arnica is a close relation to the sunflower and common daisy, says Kim T. Tran, PharmD, pharmacy manager at Jackson Memorial Hospital in Miami. “The plant contains an active ingredient, helenalin, which in small concentrations can be beneficial as an anti-inflammatory and analgesic,” she says.

While arnica gel is often used to treat many types of pain, it’s mainly for sprains and bruising, believes Tran. It's applied to the affected area and massaged into skin, she says.

Arnica can also be taken orally and is sold over the counter in tablets. Oral arnica is diluted, says Dr. Batra, and is commonly used to treat a sore throat and pain after dental work.

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Does arnica gel work?

Arnica gel's effectiveness is controversial. Some homeopathic doctors swear by its efficacy, as do many users. But there is limited scientific evidence. “Overall, studies do not show arnica gel to be a sufficient treatment for pain management or prevention of muscle damage,” says Dr. Batra.

“There are a few studies that have reported improvement in osteoarthritis after several weeks of use and that have compared its effectiveness to that of ibuprofen,” she says. One study showed that a 20% arnica gel formula sped up the healing of bruises comparably to a topical 5% Vitamin K formula.

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Still, Tran warns that arnica gel isn't a magic fix for pain. “Though this may sound promising, further clinical studies need to be conducted in order for this to be a proven remedy,” she says.

“The efficacy of helenalin for treatment of pain and swelling, when applied topically, is not supported by the current available evidence at doses of 10% or lower,” Tran says. For doses higher that 10%, more research investigating safety and effectiveness is required.

Is arnica gel safe?

Though arnica gel has not been widely studied, says Tran, she says it is generally safe for use. Side effects of topical arnica are very rare, she adds; these include redness, itching, and skin irritation. If you notice these symptoms, stop using arnica gel.

Topical arnica should not be applied to broken skin or mucous membranes, as it can cause irritation, says Dr. Batra. If you have a ragweed allergy, you’ll want to take a pass, too. “If you are allergic to ragweed or other plants of the same family that arnica belongs to, taking arnica will trigger an allergic reaction similar to what you would experience if exposed to ragweed or one of those other plants,” she warns. 

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Play it safe and don't use arnica if you are pregnant or breastfeeding. Like many other homeopathic medications, "there are not enough studies to show effects on pregnant or breastfeeding patients. Since its mechanism of action has only been theorized, it is recommended to be on the side of caution to avoid this product if you are pregnant or breastfeeding,” says Tran. This goes for both topical and oral arnica. One more word of caution about oral arnica: Almost all experts and health agencies recommend against using it at all, says Tran.