Scientific Research

Some Research on Arnica Montana

Written by Sarah Penrose

Homeopath Sarah Penrose shares some research on Arnica Montana. She states that no other homeopathic medicine has been subject to more clinical trials.

Arnica montana L. (Asteraceae) is an herbaceous perennial plant growing wild across the mountains of Europe and included on the International Union for the Conservation of Nature endangered species list with regulated harvesting confined to just several areas in France and Germany.(1)

Arnica flowers have been known for centuries as an herbal remedy. It is a therapeutic plant used traditionally to treat various pathologic conditions possessing significant anti-inflammatory, anti-osteoarthritic, anti-osteoporotic, and anti-hemorrhagic activity. Arnica shows significant antioxidant and protective effect, improves circulation, and also has analgesic properties. (2)

Arnica has a very long history with regard to its homeopathic usage since originally described by Samuel Hahnemann. (3) Known as the classic homeopathic medicine for trauma, Arnica has been widely used for the treatment of several inflammatory conditions in pain management and postoperative settings (4) and used to reduce morbidity associated with various procedures, including surgeries and treatments with lasers, and post-procedural edema and bruising. (5)

Arnica is indicated when a part of the body is bruised, with a sore feeling. This can be produced by an injury, but from other causes also such as the overexertion of an organ, or a strain, or an acute disease.(6)

No other homeopathic medicine has been subject to more controlled clinical trials .(7)

A 2021 meta analysis found that homeopathic Arnica produced small effect size:(8)

  • across a series of 18 placebo-controlled trials (just shy of significance) and is equal to conventional non-steroidal anti-inflammatory drugs in the treatment of postoperative pain, swelling, and functional limitations.
  • over and against placebo in the prevention of excessive hematoma and other surgical sequelae – comparable to that of anti-inflammatory substances.
  • A 2020 systematic review (9) concluded that perioperative Arnica seems to have a mitigating effect on ecchymosis, most notably following rhinoplasty and facelifts citing three randomized studies using Arnica 1M potency as verum, (10-12) and included randomized studies finding no evidence in: Blepharoplasty;(13) Elective hand surgery;(14) Saphenous vein stripping.(15)
  • Arnica (30X) in the minimization of postoperative edema showed a trend towards less swelling with significant difference in the cruciate ligament surgery group in all three trial groups after arthroscopy, implant or cruciate ligament surgery, (16) with other studies finding Arnica (D30) improved trismus but not pain or swelling after third molar extraction, (17) or in elective hand surgery. (14)
  • Pain minimizationwas not detected during randomized studies in rhinoplasty;(11) elective hand surgery;(14) arthroscopy, implant or cruciate ligament surgery;(16) third molar extraction;(17) and total abdominal hysterectomy.(18) A small decrease in pain score was found in tonsillectomy, with no difference in analgesia, antibiotics, swallowing function or visits to hospital.(19)
  • A randomized double-blinded, parallel-group study (GCP-standard) found Arnica (D4) preformed worse for pain, but was equivalent to Diclofenac for wound irritation, mobility, and analgesia, concluding that after foot operations Arnica can be used instead of Diclofenac to reduce wound irritation.(20)
  • Almost fifty percent of surveyed surgeons regularly incorporated Arnica into their practice. (21)

Systematic reviews and meta-analysis looking at the evidence for herbal and homeopathic Arnica in postoperative plastic surgery concluded:

  • more rigorous studies are needed to fully characterize herbal and homeopathic Arnica preparations’ effect on decreasing edema and ecchymosis after rhinoplasty.(21)
  • level II reproducible evidence supports the use of Arnica to decrease postoperative edema after rhinoplasty (22) citing RCT (11) and a topical Arnica study (23) but omitting the findings of Chaiet & Marcus (10) which Knackstedt & Gatherwright (9) cite in their conclusion that Arnica has a mitigating effect on ecchymosis, most notably following rhinoplasty and facelifts.
  • potentized Arnica (homeopathic) is effective for treating several conditions including post-traumatic and postoperative pain, edema, and ecchymosis (24) citing Ianetti(4) which concluded Arnica is more effective than placebo for post traumatic and postoperative pain, edema, and ecchymosis, suggestive that Arnica may represent a valid alternative to nonsteroidal anti-inflammatory drugs when treating specific conditions.
  • no alteration in pain perception but decreased limb swelling revealed overall treatment effect in favour of Arnica (= 0.04)(25) citing three Brinkhuis et al.,(16) methodologically sound trials (Jadad score of 5) which showed a trend toward less postoperative swelling compared to placebo, with a significant difference in the cruciate ligament reconstruction group.

A recent study demonstrated that 80% of patients presenting for elective plastic surgery utilized integrative medicine. (26)

The Ernst & Pittler 1998 systematic review (7) concluded the hypothesis that Arnica is efficacious beyond a placebo effect is not supported by rigorous clinical trials citing eight placebo controlled clinical trials examining the outcome of a single disease or condition using a non – individualized homeopathic prescription of Arnica (all potencies) as verum vs placebo.

Two studies gave statistically significant positives (Arnica superior to placebo), and two studies showed numerically positive results (advantage of the Arnica groups apparent without formal test statistics). Four studies showed significant negatives Arnica not superior to placebo).

Use of the word rigorous is interesting as Jadad scoring judged the quality of all included trials as methodologically weak. The authors’ stated that generally speaking, the more rigorous studies tended to be the ones that yielded negative findings and that there is no obvious common denominator to differentiate between positive and negative studies. For example, one trial on delayed-onset muscle soreness showed positive results for Arnica while another methodologically superior trial showed negative results. (7)

Within actual, real world homeopathic clinical settings, two individualized case studies using Arnica in the treatment of bone marrow edema (BME) of the knee joint have been published.(2) The authors conclude that individualized homeopathic medicine has a real place in treatment of the common, but difficult to treat condition of BME of the knee, and that research with more cases is needed to prove the effectiveness of this therapeutic method.

These findings are consistent with sub-group data available in a previous global systematic review (27) which found that medicines prescribed in individualized homeopathy may have small, specific treatment effects. Researchers have stated that Arnica could have been applied wrongly in Randomized Controlled Trials (RCT), as homeopaths do not treat a specific condition but rather the whole human being it is therefore not strictly according to the teaching of Hahnemann to use Arnica for trauma much like an allopathic drug (7). Is RCT the best method to prove the efficacy of homeopathy which adheres to clearly defined principles outlined in the Organon, particularly Aphorism 3; ‘‘If the physician clearly perceives what is to be cured in diseases, that is to say, in every individual case of disease (knowledge of disease, indication), if he clearly perceives what is curative in medicines, that is to say, in each individual medicine (knowledge of medicinal powers), and if he knows how to adapt, according to clearly defined principles, what is curative in medicines…’’?(28)

In 2017 Mathie et al. tested their null hypothesis that the main outcome of treatment using a non-individualized (standardised) homeopathic medicine is indistinguishable from that of placebo, as a rigorous systematic review and meta-analysis focusing on RCT of non-individualized homeopathic treatment had not previously been reported; and concluded that better designed and more rigorous RCT are needed in order to develop an evidence base that can decisively provide reliable effect estimates of non-individualized homeopathic treatment.(29)

Researchers, for the past thirty years, have attempted to build a body of substantial and impressive evidence based on clinical trials utilising the RCT, subsequently verified through meta-analyses and systematic reviews with the overall results being, at best, limited for homeopathy. (30)

The recent controversial paper the spin of electrons and their role in explaining the mechanism of action of the potentized homeopathic remedy (31) will likely play a role in future trial design because, if their hypothesis is correct, it will change the whole concept of conventional medicine, concerning diseases and their cure.


1 Falniowski et al., 2011. Arnica Montana. The IUCN Red List of Threatened Species 2011: E.T162327A5574104. Available online Https://Dx.Doi.Org/10.2305/IUCN.UK.2011-1.RLTS.T162327A5574104.En

2 Tsintzas et al., 2020. Individualized Treatment of Bone Marrow Edema of the Knee With the Aid of Classical Homeopathy: A Report of 2 Cases. Clinical Medicine Insights: Case Reports [online]. January 2020. Available from:

3 Duthen et al., 2022. Comparison of the Phytochemical Variation of Non-Volatile Metabolites within Mother Tinctures of Arnica montana Prepared from Fresh and Dried Whole Plant Using UHPLC-HRMS Fingerprinting and Chemometric Analysis. Molecules. Apr 24;27(9):2737. Available from

4 Iannitti et al., 2016. Effectiveness and Safety of Arnica montana in Post-Surgical Setting, Pain and Inflammation. American Journal of Therapeutics.  January/February 2016 23: 1. Available from:

5 Sherban et al., 2021. Growing role for arnica in cosmetic dermatology: Lose the bruise. J Cosmet Dermatol. Jul;20(7):2062-2068. Available from

6 Vithoulkas, G. 1995. Materia Medica Viva: Volume 3. Alonissos, Greece, International Academy of Classical Homeopathy.

7 Ernst & Pittler, 1998. Efficacy of homeopathic arnica: a systematic review of placebo-controlled clinical trials. Archives of Surgery [online]. Nov; 133 (11): 1187-90. Available from:

8 Gaertner et al., 2021. Is Homeopathic Arnica Effective for Postoperative Recovery? A Meta-analysis of Placebo-Controlled and Active Comparator Trials. Front Surg. Dec 17;8:680930. Available from

9 Knackstedt, R., and Gatherwright, J. 2020. Perioperative Homeopathic Arnica and Bromelain. Annals of Plastic Surgery. 84 (3), e 10–e 15. Available from:

10 Chaiet SR, Marcus BC. 2016. Perioperative Arnica montana for Reduction of Ecchymosis in Rhinoplasty Surgery. Annals of Plastic Surgery. May; 76 (5): 477-82 Available from:

11 Totonchi & Guyuron, 2007. A randomized, controlled comparison between arnica and steroids in the management of postrhinoplasty ecchymosis and edema. Plastic and Reconstructive Surgery. Jul; 120 (1): 271-4. Available from:

12 Seeley et al., 2006. Effect of Homeopathic Arnica montana on Bruising in Face-lifts. Archives of Facial Plastic Surgery. Apr; 82 (4): 459-468. Available from

13 Kotlus et al., 2010. Evaluation of Homeopathic Arnica montana for Ecchymosis After Upper Blepharoplasty: A Placebo-Controlled, Randomized, Double-Blind Study. Ophthalmic Plastic & Reconstructive Surgery. 26 (6), 395-397. Available from

14 Stevinson et al., 2003. Homeopathic arnica for prevention of pain and bruising: randomized placebo-controlled trial in hand surgery. Journal of the Royal Society of Medicine. Feb; 96 (2): 60-5. Available from

15 Ramelet et al., 2000. Homeopathic Arnica in postoperative haematomas: a double-blind study. Dermatology. 201 (4): 347-8. Available from

16 Brinkhaus et al., 2006. Homeopathic arnica therapy in patients receiving knee surgery: results of three randomised double-blind trials. Complementary Therapies in Medicine. Dec; 14 (4): 237-46. Available from:

17 Lökken et al., 1995. Effect of homoeopathy on pain and other events after acute trauma: placebo controlled trial with bilateral oral surgery. BMJ clinical research h edition. Jun 3; 310 (6992): 1439-42. Available from

18 Hart et al., 1997. Double-blind, placebo-controlled, randomized clinical trial of homoeopathic arnica C30 for pain and infection after total abdominal hysterectomy. Journal of the Royal Society of Medicine. Feb; 90 (2): 73-8. Available from:

19 Robertson et al., 2007. Homeopathic Arnica montana for post-tonsillectomy analgesia: a randomised placebo control trial. Homeopathy. Jan; 96 (1): 17-21. Available from

20 Karow et al., 2008. Efficacy of Arnica montana D4 for healing of wounds after Hallux valgus surgery compared to diclofenac. Journal of Alternative and Complement Medicine [online]. Jan-Feb;14 (1):17-25. Available from

21 Ong et al., 2016. Interventions to decrease postoperative edema and ecchymosis after rhinoplasty: A systematic review of the literature. Plastic and reconstructive surgery. 5, 1448. Available from

22 Ruan et al., 2019. Integrative Medicine in Plastic Surgery: A Systematic Review of Our Literature. Annals of Plastic Surgery. Apr; 82 (4): 459-468. Available from

23 Simsek et al., 2016. Topical Application of Arnica and Mucopolysaccharide Polysulfate Attenuates Periorbital Edema and Ecchymosis in Open Rhinoplasty: A Randomized Controlled Clinical Study. Plastic and Reconstructive Surgery. Mar; 137 (3): 530e-535e. Available from

24 Lee et al., 2017. The effectiveness of postoperative intervention in patients after rhinoplasty: a meta-analysis. European Archives of Oto-rhino-laryngology: official journal of the European Federation of Oto-rhino-laryngological Societies (EUFOS): affiliated with the German society for Oto-rhino-laryngology – Head and Neck surgery. Jul; 274 (7), 2685-2694. Available from

25 Barlow et al., 2013. The effect of complementary therapies on post-operative pain control in ambulatory knee surgery: a systematic review. Complementary Therapies in Medicine. Oct; 21 (5): 529-34. Available from

26 Patel et al., 2017. Utilization and Perception of Integrative Medicine Among Plastic Surgery Patients. Ann Plast Surg. May;78(5):557-561. Available from

27 Mathie et al., 2014. Randomised placebo-controlled trials of individualised homeopathic treatment: systematic review and meta-analysis. Systematic Reviews 3, 142. Available from:

28 Hahnemann, S. 2005. Organon of Medicine. Sixth edition. Translated from German by W. Boericke. New Delhi. Indian Books & Periodicals Publishers. (Originally published in 1842).

29 Mathie et al., 2017. Randomised, double-blind, placebo-controlled trials of non-individualised homeopathic treatment: systematic review and meta-analysis. Systematic Reviews. 6 (1), 63. Available from

30 Levy, D., Homeopathy’s ‘dark night of the soul’: reflections on professional transition in Australia. Similia, The Australian Journal of Homeopathic Medicine. June 2019; 31 (1), 39-41.

31 Vithoulkas & Berghian-Grosan, 2020. The Spin of Electrons and the Proof for the Action of Homeopathic Remedies. Journal of Medicine and Life. July-September 13 (3) 278–282. Available from:

About the author

Sarah Penrose

Sarah Penrose (BSc(hons) hom) is an Australasian homeopath. Sarah has three qualifications in homeopathy, oversees the Australian Homeopathic Association research portfolio, writes a Substack Evidence Based Complementary Medicine, and can be contacted via

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