Hairy arnica

Other Names

Arnica amplifoliaArnica amplifolia Rydb.Arnica arachnoideaArnica arachnoidea Rydb.Arnica coloradensisArnica coloradensis Rydb.Arnica confinisArnica confinis GreeneArnica crocinaArnica crocina GreeneArnica macillentaArnica macillenta GreeneArnica mollisArnica mollis Hook.Arnica mollis var. mollisArnica mollis var. scaberrimaArnica mollis var. scaberrima (Greene) SmileyArnica mollis var. silvaticaArnica mollis var. silvatica (Greene) MaguireArnica rivularisArnica rivularis GreeneArnica scaberrimaArnica scaberrima GreeneArnica silvaticaArnica silvatica GreeneArnica subplumosaArnica subplumosa GreeneArnica subplumosa var. macillentaArnica subplumosa var. macillenta (Greene) A.NelsonArnica subplumosa var. silvaticaArnica subplumosa var. silvatica (Greene) A.NelsonArnica subplumosa var. subplumosasoft arnicasubalpine arnicawoolly arnicawooly arnica

Synopsis

Hairy Arnica (Arnica mollis): A Comprehensive Reference

1. Identity and Botanical Description

1.1 Nomenclature and Taxonomy

Arnica mollis, commonly known as hairy arnica or soft arnica, is a perennial herbaceous plant belonging to the family Asteraceae. It was first formally named and described by the botanist William Jackson Hooker in 1834 in his Flora Boreali-Americana publication. The specific epithet mollis means "soft," referring to the soft hairs on the leaves. The genus name Arnica may be derived from the Greek arni, meaning "lamb," in reference to the plants' soft, hairy leaves.

Arnica is a genus of perennial, herbaceous plants in the sunflower family (Asteraceae). Arnica is also known by the names mountain tobacco and, confusingly, leopard's bane and wolfsbane — two names that it shares with the entirely unrelated genus Aconitum. This circumboreal and montane (subalpine) genus occurs mostly in the temperate regions of western North America, with a few species native to the Arctic regions of northern Eurasia and North America.

Within the genus, Arnica mollis belongs to the subgenus Chamissonis, a grouping that includes several closely related North American species such as A. chamissonis, A. longifolia, A. amplexicaulis, and A. parryi. It is distinguished from the more pharmacologically prominent European species Arnica montana L. by both geography and certain aspects of its phytochemistry, discussed in detail below.

1.2 Morphological Description

Arnica mollis is a perennial herb producing one or more hairy, glandular, mostly naked stems 15 to 70 centimeters tall. There are 2 to 4 pairs of leaves along mainly the lower half of the stem, each oblong in shape and 4 to 20 centimeters in length. Arnica mollis is one of the hairiest members of this genus; leaf edges, leaf faces, stems, and phyllaries all have a covering of long silky white hairs, often glandular (sticky).

The thick stems bear 2 to 4 pairs of leaves (usually 3) and may be single or lightly branched towards the top. Leaves are sessile, lacking any stalks. Leaf edges are entire or irregularly toothed, while the tips are pointed. Flower heads (single or up to 7) consist of between 10 and 22 pointed green phyllaries, the same number of yellow ray florets, and several dozen disc florets.

1.3 Geographic Distribution and Habitat

Arnica mollis is found in sections of Canada (Alberta, British Columbia, Quebec, Nunavut, Yukon, Northwest Territories) and the western United States south to Tulare County, California, and Rio Arriba County, New Mexico. There may be a small disjunct population of the species in Coös County, New Hampshire. According to the Flora of North America, plants of this species typically grow in wet meadows, conifer forests, stream banks, and areas with melting snow at elevations of 1,000–4,000 m (3,300–13,100 ft) above sea level.

As of December 2024, the conservation group NatureServe listed Arnica mollis as Secure (G5) worldwide. This status was last reviewed on 13 May 2016. At the state and provincial levels, the species is listed as Apparently Secure (S4) in Montana; Vulnerable (S3) in Nevada and Alberta; Possibly Extirpated in the Northwest Territories; and No Status Rank (not assessed) across the rest of the species' range.

1.4 Common Forms and Preparations

As a member of the Arnica genus, A. mollis is used, like related species, in a range of topical preparations. Arnica tinctures (hydroalcoholic extracts) and salves have been used externally for their anti-inflammatory, bactericidal, antineuralgic, antirheumatic, antiseptic, counterirritant, and wound-healing effects. Commercially, arnica is used in cosmetics, shampoos, hair tonics, anti-dandruff products, bath products, and arnica oil is used in perfumery. Arnica is also the basis of a homeopathic remedy promoted for aiding bruise recovery.

The primary dosage forms for arnica species in general include:

Tinctures: According to the European Pharmacopoeia, a standard tincture is a 70% hydroethanolic preparation from arnica flowers, compounded with at least 0.04% sesquiterpene lactones.
Gels and creams: Patients apply a thin layer of arnica gel to affected areas; one clinically studied formulation contained 50 g of arnica fresh plant tincture (drug-to-extract ratio 1:20 in 50% ethanol) per 100 g of gel.
Macerated oils and ointments: Diluted arnica is often applied to the skin surface and purposely not covered with bandages. Arnica oil, which is a macerated oil from the arnica flowers, also has topical uses.
Compresses and infusions: In traditional medicine, arnica was commonly applied as a compress or salve for addressing bruises, swelling, and injuries, and also used in foot baths to soothe sore feet.

2. Traditional and Historical Use

2.1 European Traditional Medicine

Arnica has a history of folk medicine use in many locations, including North America, Germany, and Russia. The herb has been used in folk remedies since the sixteenth century. Arnica may have been first mentioned in the 12th century, when legendary healer Hildegard von Bingen wrote about an herb that closely matches the plant in her book on health and healing, Physica. In 1805, Samuel Hahnemann, the founder of homeopathy, published his findings on extremely diluted preparations of arnica.

Extracts of A. montana flowers have a long history of use in European traditional medicine as a remedy to treat several ailments, including pain, injuries, haematomas, dislocations, sprains, bruising, edema associated with fractures, rheumatic muscle and joint complaints, inflammations of the mucous membranes of the mouth and throat, furuncles, inflamed insect bites, and surface phlebitis. In Medieval times, mild infusions of arnica were used as an emmenagogue and for easing the pain of delivery. The herb was approved for external use by the German Commission E in 1986.

2.2 Native American and North American Traditional Use

Native Americans referred to arnica as mountain tobacco and leopard's bane, and employed the plant for sprains, bruises, and wounds. The flowers of Arnica species native to North America, including A. mollis, are used in much the same way as A. montana. Detailed information on North American species usage is documented in Michael Moore's books on medicinal plants of the Mountain West and Pacific West, and in Daniel Moerman's Native American Ethnobotany database.

Several Native American tribes used the roots to prepare a tea that would aid in the alleviation of back pain. Some of the first recorded European folk remedies date back to the early 16th century. Ancient Native American and European cultures would soak arnica leaves in water to create a poultice to apply to injuries. As technology advanced, people began to use alcohol to formulate extracts for ointments.

2.3 Traditional Preparations and Purposes

Across different traditions, the primary uses of arnica species — including, by extension, A. mollis among North American peoples — converge around a core set of applications:

Arnica was used historically in an attempt to treat back pain, sore eyes, swelling, cuts, and bruises.
It is taken by mouth for sore throats and pain, and applied externally primarily to bruises, but also to sprains and sore limbs.
A compress soaked in an arnica infusion may relieve the inflammation of phlebitis. A few drops of arnica tincture added to warm water in a foot bath was used to relieve fatigue and soothe sore feet.
A hair rinse prepared with arnica extract has been used to treat alopecia neurotica, an anxiety condition leading to hair loss.

3. Key Constituents and Active Compounds

3.1 Sesquiterpene Lactones

Arnica tincture is a herbal medicinal preparation with anti-inflammatory activity used traditionally for the topical treatment of blunt injuries as well as rheumatic muscle and joint complaints. Its main bioactive constituents are sesquiterpene lactones (STLs) of the helenalin and 11α,13-dihydrohelenalin types. Among these, a variety of esters of helenalin and 11α,13-dihydrohelenalin with low-molecular-weight carboxylic acids — namely acetic, isobutyric, methacrylic, methylbutyric, and tiglic acid — represent the main constituents, in addition to small amounts of the unesterified parent STLs.

A plethora of reports exist on the pharmacological activities of these STLs, and it appears unquestioned that they represent the main active principles responsible for the herbal drug's efficacy. Helenalin esters predominated over dihydrohelenalin in some populations, and this holds great importance as arnica extracts primarily composed of helenalin esters were reported to show greater efficacy in various anti-inflammatory assays compared to extracts predominantly comprising dihydrohelenalin esters.

With respect to Arnica mollis specifically, a 2008 phytochemical study compared the STL profiles and anti-inflammatory activity of twelve Arnica species. Extracts of twelve arnica species were investigated for inhibition of human neutrophil elastase release and inhibition of transcription factor NF-κB, with statistical analyses revealing significant differences in inhibitory capacities between extracts. Sesquiterpene lactones of the helenanolide type — known inhibitors of human neutrophil elastase release and NF-κB — are present in large amounts in the very active extracts of A. montana and A. chamissonis.

3.2 Flavonoids

Among the biologically active ingredients in the flower heads of arnica plants are sesquiterpenes, flavonoids, and phenolic acids. A number of flavonoids are present, including isoquercitrin, luteolin, kaempferol, quercetin, and astragalin. In arnica flowers, the most dominant flavonoid was found to be quercetin 3-O-glucuronic acid, while 3,5-dicaffeoylquinic acid was the major phenolic acid; the total content of flavonoids and phenolic acids varied in studied samples from 0.60 to 1.70%.

Arnica mollis displays a distinctive flavonoid profile within the genus. Twenty-eight flavonoid aglycones have been identified from Arnica chamissonis, A. longifolia, A. amplexicaulis, A. mollis, and A. parryi of the subgenus Chamissonis. The flavonoid pattern was largely homogeneous, but only A. mollis is an exception by the occurrence of 7-methylation.

3.3 Phenolic Acids and Other Constituents

A wide range of chemical compounds including sesquiterpene lactones and their short-chain carbonic acid esters, flavonoids, carotenoids, essential oils, diterpenes, arnidiol, pyrrolizidine alkaloids, coumarins, phenolic acids, lignans, and oligosaccharides are found in different parts of arnica plants. The flowers also contain caffeic acid and its derivatives and an essential oil containing fatty acids, carotenoids, and thymol derivatives, along with the coumarins umbelliferone and scopoletin.

Phytochemical analyses of arnica plants confirmed the production of STLs (helenalin, dihydrohelenalin, dihydrohelenalin acetate), sterols (sitosterol, stigmasterol), phenolic acids (chlorogenic acid, caffeic acid), thymol derivatives, and essential oil.

3.4 Pyrrolizidine Alkaloids

The pyrrolizidine alkaloids tussilagine and isotussilagine may pose a risk of hepatotoxicity in arnica preparations. However, other constituents include diterpenes and pyrrolizidine alkaloids (tussilagine and isotussilagine). The degree of risk from these alkaloids in topical preparations at standard concentrations is generally considered low, but is a recognized safety consideration discussed further below.

4. Mechanisms of Action

4.1 NF-κB Inhibition

The active ingredients mediating the pharmacological effect of arnica are mainly sesquiterpene lactones, such as helenalin, 11α,13-dihydrohelenalin, chamissonolid, and their ester derivatives. While these compounds affect various cellular processes, current data do not fully explain how sesquiterpene lactones exert their anti-inflammatory effect. Helenalin, and to a much lesser degree 11α,13-dihydrohelenalin and chamissonolid, inhibit activation of transcription factor NF-κB.

Helenalin inhibits NF-κB activation in response to four different stimuli in T-cells, B-cells, and epithelial cells, and abrogates κB-driven gene expression. This inhibition is selective, as the activity of four other transcription factors (Oct-1, TBP, Sp1, and STAT 5) was not affected. Inhibition is not due to a direct modification of the active NF-κB heterodimer; rather, helenalin modifies the NF-κB/IκB complex, preventing the release of IκB.

These data suggest a molecular mechanism for the anti-inflammatory effect of sesquiterpene lactones which differs from that of other nonsteroidal anti-inflammatory drugs (NSAIDs), indomethacin, and acetyl salicylic acid. Sesquiterpene lactones, secondary plant metabolites from flowerheads of arnica, exert anti-inflammatory effects mainly by preventing NF-κB activation because of alkylation of the p65 subunit.

4.2 Effects on Matrix Metalloproteinases and Chondrocyte Function

Sesquiterpene lactones, the active constituents in arnica, have anti-inflammatory properties and inhibit binding of transcription factors AP-1 and NF-κB to DNA. A tincture prepared from arnica flowers suppressed collagenase-1 (MMP1) and interstitial collagenase-13 (MMP13) mRNA levels in human articular chondrocytes in vitro. MMP13 and MMP1 enzymes are thought to play a significant role in cartilage and joint destruction and inflammation seen in osteoarthritis and rheumatoid arthritis.

4.3 Platelet Function Inhibition

Another study found that sesquiterpene lactones inhibit platelet function by interacting with platelet sulfhydryl groups, probably associated with reduced phospholipase A2 activity.

4.4 Immunomodulatory Effects

Both arnica tinctures and sesquiterpene lactones were found to suppress NF-κB activation and IL-12 production in dendritic cells at high concentrations, but can also have immunostimulatory effects when diluted. Helenalin and its derivatives are known for anti-cancer and anti-inflammatory effects via inhibiting NF-κB and telomerase activity and impairing protein and DNA synthesis, suggesting that helenalin is a potential candidate for the treatment of deregulated and unwanted T cell-mediated immune responses.

4.5 Antileishmanial Activity

The main bioactive constituents are sesquiterpene lactones of the helenalin and 11α,13-dihydrohelenalin types. Besides anti-inflammatory activity, the tincture and its isolated STLs have antileishmanial activity. In a recent in vivo study, a treatment with arnica tincture cured cutaneous leishmaniasis (CL) in a golden hamster model. This represents an emerging area of research interest for the broader Arnica genus.

5. Scientific Evidence by Area of Use

Important context: The overwhelming majority of clinical research on Arnica as a medicinal plant has been conducted on preparations derived from Arnica montana L. or, to a lesser extent, Arnica chamissonis. Arnica mollis itself has not been the subject of dedicated clinical trials. What follows is the available human and clinical evidence for the Arnica genus, with phytochemical parallels to A. mollis noted where the evidence permits.

5.1 Osteoarthritis

Evidence strength: Moderate — limited but positive for topical phytotherapeutic preparations.

A few clinical trials suggest that topical arnica is helpful for osteoarthritis. Knuesel and coworkers reported the results of a 6-week multicenter trial focused on the safety and efficacy of an A. montana gel formulation involving 79 patients with mild-to-moderate osteoarthritis of the knee. Patients were asked to apply a thin layer of arnica gel to the affected knee two times per day; 100 g of gel contained 50 g of arnica fresh plant tincture (drug-to-extract ratio 1:20 in 50% ethanol). The study demonstrated that the topical application of the arnica gel was effective, being at the same time safe and well tolerated, with the exception of an allergic reaction in one patient.

This open multicenter trial involved 26 men and 53 women with mild to moderate osteoarthritis (OA) of the knee. After 3 and 6 weeks, significant decreases in median total scores on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evident in the intention-to-treat and per-protocol populations (both P < .0001). Scores on the pain, stiffness, and function subscales also showed significant reductions at these timepoints.

A second key study addressed hand osteoarthritis. The effects of ibuprofen (5%) and arnica (50 g tincture/100 g, DER 1:20), as gel preparations in patients with radiologically confirmed and symptomatically active osteoarthritis of the interphalangeal joints of the hands, were evaluated in a randomized, double-blind study in 204 patients. There were no differences between the two groups in pain and hand function improvements, or in any secondary end points evaluated. The results confirm that this preparation of arnica is not inferior to ibuprofen when treating osteoarthritis of the hands.

Limitations: The knee OA trial was open-label and uncontrolled; the hand OA study had a non-inferiority rather than superiority design. Both studies used A. montana-based preparations only.

5.2 Bruising and Wound Healing

Evidence strength: Moderate — positive signal for accelerating bruise resolution at higher concentrations.

Clinical trials suggest that topical arnica significantly reduces bruising compared with placebo or low-concentration vitamin K ointments. Leu and colleagues described a rater-blinded randomized controlled trial on the ability of a topical 20% arnica formulation to enhance the resolution of laser-induced bruising. In this study involving healthy volunteers aged between 21 and 65, four bruises of 7 mm diameter each were created on the bilateral upper inner arms using a 595 nm pulsed-dye laser. The patients were divided into four groups, each randomly receiving 5% vitamin K, 1% vitamin K, 0.3% retinol, 20% arnica, or white petrolatum.

5.3 Muscle Soreness

Evidence strength: Weak and mixed — one small study found the opposite of the anticipated effect.

No significant differences in pain scores were seen before exercise between arnica and placebo groups. Pain scores on legs treated with arnica were higher than scores on those receiving placebo 24 hours after exercise (3.04 vs. 2.36; p < 0.005). Pain scores on day 3 and day 4 were not significantly different between groups. Rather than decreasing leg pain, arnica was found to increase leg pain 24 hours after eccentric calf exercises. This effect did not extend to the 48-hour measurement. This randomized, double-blind, placebo-controlled trial enrolled 53 subjects.

A small study reported that topical arnica actually increased pain 24 hours after calf exercises. The muscle pain evidence therefore remains inconclusive, and no net benefit over placebo has been consistently demonstrated for delayed-onset muscle soreness.

5.4 Postoperative Applications

Evidence strength: Mixed — positive signals for some surgical contexts, null for others.

Studies on postoperative benefits from use of arnica are mixed. It reduced swelling in patients following knee surgery, reduced pain following tonsillectomy, and may reduce bruising from rhinoplasty, but was not helpful after blepharoplasty.

5.5 Homeopathic Arnica — Systematic Review Evidence

Evidence strength: Very weak — systematic reviews have generally not supported efficacy beyond placebo for homeopathic preparations.

Placebo-controlled trials of homeopathic arnica have been conducted in patients and healthy volunteers being treated for delayed-onset muscle soreness (measuring soreness intensity and duration, maximal isometric muscle strength, and serum creatine kinase concentrations), prevention of postsurgical dental complications (pain, trismus, edema, bleeding, and wound healing), and acute trauma outcomes including pulse rate, blood pressure, respiratory rate, and subjective symptoms. The overall conclusions of such systematic reviews have generally not supported the efficacy of homeopathic dilutions over placebo.

5.6 Antimicrobial and Antileishmanial Activity

Evidence strength: Preclinical only — human evidence absent.

In vitro studies show that arnica has antimicrobial and anti-inflammatory properties. In in vitro studies, arnica tincture and isolated arnica sesquiterpene lactones demonstrated strong antileishmanial activity. In addition, a first in vivo study with cutaneous leishmaniasis in golden hamsters infected with L. braziliensis showed curative activity of an ethanolic arnica tincture applied topically on the lesions. Human trials for antileishmanial use are underway (e.g., NCT06822478) but results are not yet established.

6. Body Systems and Health Areas

The body systems and health areas for which arnica species — and, by extension, Arnica mollis as a related North American species with similar phytochemistry — have been applied include:

Musculoskeletal system: Arnica is one of the first remedies to turn to for any muscle, joint, and connective tissue injuries causing local inflammation, swelling, and pain. It is largely used to treat bruises, sprains, oedema from fractures, rheumatic pain, joint aches, varicose veins, haemorrhoids, and inflamed insect bites.
Dermatological / skin health: Arnica flowers in ointments, creams, or gels are most commonly used for the topical treatment of bruises and sprains. They have also been recommended for inflammation due to insect bites and for stiff, inflamed joints. Such remedies seem to have a mild anti-inflammatory effect with some ability to relieve pain.
Oral and mucous membrane health: Arnica preparations are cited by ESCOP for uses including sprains, inflamed insect bites, gingivitis, and topical relief of rheumatic discomfort.
Hair and scalp: Arnica is also found in some hair products.
Cardiovascular (topical/circulatory): The principal active constituents are described as antirheumatic, antiarthritic, antihyperlipidaemic, and respiratory analeptic.

7. Dosage Forms and Reported Dosages

Dosage information from identified clinical and pharmacopoeial sources pertaining to the arnica genus includes:

Topical gel for osteoarthritis (knee): A 6-week multicenter trial used a gel containing 50 g of arnica fresh plant tincture (drug-to-extract ratio 1:20 in 50% ethanol) per 100 g, applied twice daily to the affected knee.
Topical gel for hand osteoarthritis: A randomized, double-blind study in 204 patients evaluated arnica at 50 g tincture/100 g gel (DER 1:20) applied over 21 days.
Topical formulation for bruising: Leu and colleagues used a topical 20% arnica formulation in their rater-blinded randomized controlled trial on laser-induced bruising.
European Pharmacopoeia standard for tincture: According to the European Pharmacopoeia, the solution is a 70% hydroethanolic tincture prepared from the flowers of Arnica montana L., compounded with at least 0.04% sesquiterpene lactones.
Sesquiterpene lactone content (flowers): Sesquiterpene lactones (helenalin, 11α,13-dihydrohelenalin and their short-chain carbonic acid esters) occur at approximately 0.3–1% of dry weight in the flower heads and 0.1–0.5% in leaves; flavonoids constitute 0.6–1.7%.

No dedicated dosage studies specific to Arnica mollis as an isolated ingredient have been identified in the peer-reviewed literature.

8. Safety Considerations and Interactions

8.1 Contact Dermatitis and Sensitization

Arnica montana is one of the oldest and most important drug plants. Besides its healing effects it also reveals sensitizing properties. From the literature more than 35 references with more than 100 cases of contact dermatitis have been cited. In most cases sensitization was induced by self-treatment with tincture of arnica, whereas occupational contact dermatitis in drug sellers or pharmacists is rare. The sesquiterpene lactones helenalin, its acetate, and methacrylate have been proved to be the primary sensitizers.

During patch tests in vivo and in clinical trials, arnica extract has proven to be non-irritating, non-sensitizing, and non-phototoxic at various concentrations and over short-term use. However, clinical trials have reported contact allergic dermatitis, or a delayed type IV hypersensitivity reaction, in some subjects, caused by sesquiterpene lactones. In a clinical study involving 443 patients, five subjects (1.1%) showed positive reactions to patch tests with arnica. They were referred for eczematous allergic reactions of the hands or face, resulting in itching and dry skin.

8.2 Cross-Reactivity with Asteraceae

Arnica is not recommended for prolonged usage or for persons with sensitivity to members of the Asteraceae family, such as daisies, ragweed, and chrysanthemums. The same structural sensitizer (sesquiterpene lactones) responsible for anti-inflammatory activity is also responsible for allergic sensitization potential. Despite its known immunosuppressive action, arnica has been classified as a plant with strong potency to induce allergic contact dermatitis.

8.3 Toxicity of Internal Use

Patients should be discouraged from using oral arnica in amounts greater than commonly found in foods or in homeopathic formulations because of reports of severe health risks, including coma, hypertension, renal toxicity, cardiotoxicity, muscle paralysis, and death. Patients should also be instructed not to apply arnica to abraded skin or open wounds, and advised against prolonged topical use because of the potential for irritant or allergic contact dermatitis.

Taken internally, arnica can cause stomach pain, vomiting, diarrhea, and inflammation of the mucous membranes. At high doses, nervousness, altered pulse, and muscular weakness have been reported. Difficulty breathing may precede cardiac arrest. Deaths have occurred.

8.4 Pharmacokinetics and Topical Safety

The plasma concentration of STLs after the topical application of arnica tincture was very far from a dose where toxicity could be expected. Additionally, tests for corrosive or irritant activity as well as acute and repeated-dose dermal toxicity did not show any positive results after the administration of amounts of arnica tincture needed for the treatment of cutaneous leishmaniasis. Consequently, no toxic effects are expected from topical use, other than the known sensitization potential of the STLs.

A fast metabolism, dominated by glutathione conjugation, and an extensive absorption of the STLs into the skin were observed with only a low degree of permeation. Thus, an accumulation in the skin was found.

8.5 Platelet Interaction

Sesquiterpene lactones inhibit platelet function by interacting with platelet sulfhydryl groups, probably associated with reduced phospholipase A2 activity. This raises a theoretical interaction concern for individuals using anticoagulant or antiplatelet medications, particularly if arnica preparations are used extensively or applied to large skin surface areas, though this remains largely a theoretical rather than clinically documented risk in the topical setting.

8.6 Pyrrolizidine Alkaloid Content

The pyrrolizidine alkaloids tussilagine and isotussilagine may pose a risk of hepatotoxicity. In arnica species, these alkaloids are described as non-hepatotoxic representatives of the pyrrolizidine class because they lack the 1,2-unsaturated necine ring system associated with liver damage. However, their presence is noted as a constituent of interest in regulatory contexts.

8.7 Use in Pregnancy

Although external applications might not trigger uterine contractions, pregnant women are advised to avoid arnica.

8.8 Application to Broken Skin

Patients should be instructed not to apply arnica to abraded skin or open wounds and advised against prolonged topical use because of the potential for irritant or allergic contact dermatitis.

9. Regulatory and Pharmacopoeial Status

For its use as a traditional herbal medicine, the European Directorate for the Quality of Medicines (EDQM) provides quality standards monographs for arnica flower and arnica tincture in the European Pharmacopoeia, while the European Medicines Agency (EMA) provides labeling standards monographs for prepared forms (tinctures and liquid extracts). For use in anthroposophy, the whole fresh flowering plant, the fresh or dried inflorescence, the fresh or dried subterranean parts, and essential oil of the subterranean parts are described in the Anthroposophic Pharmaceutical Codex. For arnica-based homeopathic preparations marketed in the European Union, quality standards monographs are provided in both the French Pharmacopoeia and German Homoeopathic Pharmacopoeia.

Regulatory monographs specifically addressing Arnica mollis as a distinct pharmacopoeial ingredient do not exist in the European Pharmacopoeia or major WHO monograph series; A. montana is the primary officinal species globally, with A. chamissonis subsp. foliosa recognized as an official substitute in some jurisdictions. Arnica mollis remains a subject of ethnobotanical and preliminary scientific inquiry rather than a fully monographed or independently regulated species.

References

Health Conditions

Health conditions that Hairy arnica may help support.

No conditions available.

Body Systems

Body systems that Hairy arnica may help support.

No body systems available.