Arnica montana L. (Asteraceae/Compositae)
Doronicum arnica Desf., D. montanum Lam
A perennial herb, 20–50 cm high. Aerial portion consists of a basal rosette
of entire oblanceolate leaves up to 17 cm long, five to seven veins, from the
centre of which projects an erect, simple, glandular hairy stem up to 0.6 m
high. Stem bears two to four pairs of cauline leaves, ovate, elliptic-oblong,
lanceolate or oblanceolate, with rounded or rounded-toothed apex and clothed
with numerous nonglandular and glandular hairs, up to 16 cm long and 5 cm wide.
Peduncles, one to three, bearing alternate bracteoles, extending from the uppermost
pair of cauline leaves; glandular–puberulent, each terminating in a hemispherical
or turbinate capitulum bearing orange-yellow flowers, which are tubular. Fruits,
black to brown, five-ribbed, with a bristle tuft of hairs
Plant material used
dried flower heads
Contains not less than 0.40% of total sesquiterpene lactones calculated as helenalin
tiglate, determined by high-performance liquid chromatography
Major chemical constituents
The major constituents include the essential oil (0.5%), fatty acids (content
not specifi ed), thymol (content not specifi ed), pseudoguaianolide sesquiterpene
lactones (0.2–0.8%) and fl avonoid glycosides (0.2–0.6%). The primary
sesquiterpene lactones are helenalin, 11α,13-dihydrohelenalin and their
fatty acid esters. Flavonoids include glycosides and/or glucuronides of spinacetin,
hispidulin, patuletin and isorhamnetin, among others
Uses supported by clinical data
Uses described in pharmacopoeias and well established
As a topical counterirritant for treatment of pain and infl ammation resulting
from minor injuries and accidents, including bruises, ecchymoses, haematomas
and petechiae. Treatment of infl ammation of the oral mucous membranes, insect
bites and superfi cial phlebitis.
Uses described in traditional medicine
Treatment of indigestion, cardiovascular disease, and rheumatism. As an emmenagogue.
Proven pharmacological activity
Analgesic and anti-inflammatory, Antioxidant, Antitumour, Choleretic, Uterine
Numerous cases of dermatitis of toxic or allergic origin have been reported,
usually following prolonged, external application of a tincture of Flos Arnicae.
The compounds responsible for the hypersensitivity reaction are the sesquiterpene
lactones helenalin and helenalin acetate. Cross-reactivity to other Asteraceae
flowers has been reported. The flower heads are irritant to the mucous membranes
and ingestion may result in gastroenteritis, muscle paralysis (voluntary and
cardiac), an increase or decrease in pulse rate, heart palpitations, shortness
of breath and death. A fatal case of poisoning following the ingestion of 70.0
g of a tincture of the fl ower heads has been reported. A case of severe mucosal
injuries following the misuse of an undiluted mouth rinse with a 70% alcohol
content, which also contained oil of peppermint and Flos Arnicae, has been reported
Flos Arnicae is used in traditional systems of medicine as an emmenagogue, and
its safety during pregnancy and nursing has not been established. Therefore,
in accordance with standard medical practice, the fl ower heads should not be
administered to pregnant or nursing women. Flos Arnicae is also contraindicated
in cases of known allergy to Arnica or other members of the Asteraceae (Compositae).
A fatal case of poisoning following the ingestion of 70.0 g of a tincture of
Flos Arnicae has been reported. Internal use of Flos Arnicae or extracts of
the fl ower heads is not recommended. For external use only. Do not apply to
open or broken skin. Keep out of the reach of children.
Avoid excessive use. Chronic, frequent external applications may induce allergy-related
skin rashes with itching, blister formation, ulcers and superfi cial necrosis.
Prolonged treatment of damaged or injured skin or indolent leg ulcers may induce
the formation of oedematous dermatitis with the formation of pustules.
Carcinogenesis, mutagenesis, impairment of fertility
Helenalin has cytotoxic effects in vitro (see Experimental pharmacology). However,
in the Salmonella/microsome assay, helenalin was not mutagenic in S. typhimurium
strains TA102, TA98 or TA100 at concentrations of up to 30 µg/ml.
Pregnancy: teratogenic effects
Intraperitoneal administration of 6.0–20.0 mg/kg bw of helenalin was not
teratogenic in mice.
Pregnancy: non-teratogenic effects
See Warnings. For external use only. Do not apply to abraded or broken skin.
No information available on precautions concerning drug interactions; or drug
and laboratory test interactions.
Dried flower heads and other galenical preparations. Store protected from light
(Unless otherwise indicated)
For external applications only, apply undiluted externally on the affected area
two or three times daily: infusion for compresses, 2 g of Flos Arnicae per 100
ml water; tincture for compresses, one part Flos Arnicae to 10 parts 70% ethanol;
mouth rinse, 10-fold dilution of tincture, do not swallow; ointment, 20–25%
tincture of Flos Arnicae or not more than 15% essential oil