Arnica

Arnica: what was it used for?

For bruises, outwardly. “In countries where Arnica is indigenous, it has long been a popular remedy,” Grieve wrote, and the tincture was laid on sprains, bruises, and wounds and painted on unbroken chilblains, though “Repeated applications may produce severe inflammation.” It was seldom given by mouth because it irritated the stomach; when it was, it was a stimulant and diuretic for low fevers and palsies. A footbath with the tincture eased tender feet, and applied to the scalp, she added, “it will make the hair grow.”

Arnica: what does modern science say?

The European Medicines Agency’s herbal committee accepts the flower, applied to the skin, as a traditional herbal medicine, “exclusively based upon long-standing use,” for the relief of bruises, sprains, and localised muscular pain (monograph of 2014). Its assessment report names sesquiterpene lactones, helenalin and dihydrohelenalin and their esters, as the most relevant constituents, with flavonoids and essential oil. Most of the reviews of arnica trials read for this entry concern homeopathic preparations, which are not the herbal medicine of the monograph: a 1998 review of eight placebo-controlled trials of homeopathic arnica concluded that the claim of efficacy “beyond a placebo effect is not supported by rigorous clinical trials,” and a 2016 review of arnica and bromelain for bruising and swelling after procedures found “insufficient data to support use.”

Arnica: what did the older authorities say?

King’s American Dispensatory

“Locally arnica is irritant, the preparations of the flowers being most powerful,” and “Even when used as a local dressing for wounds dangerous inflammation, with vesication, has occurred.” Taken in large doses it caused heat in the throat, vomiting, purging, spasms, laboured breathing, and coma; King’s knew no antidote and records a death from the tincture.