Arnica
For bruising and swelling after surgery, a meta-analysis of homeopathic arnica found a small effect over placebo that missed significance, and an earlier review found no benefit. Herbal arnica on the skin gave mixed results on bruising and muscle soreness, and matched ibuprofen gel in hand arthritis. Eating the plant has caused severe gastroenteritis and death.
Add to Bio HackChecked 2026-11-09
- Status
- Sold in the US as topical herbal products and as homeopathic pills. Not FDA-approved for any condition.
- Also called
- Arnica montana, arnica gel, arnica cream, arnica ointment, homeopathic arnica, Arnica 30C, Arnica 30X, Arnica D30, leopard's bane, mountain tobacco, wolf's bane
- Taken for
- bruising, swelling after surgery, swelling, muscle soreness, joint pain, osteoarthritis, pain after surgery
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help1
Reported risks2
- LimitedCase reports: eating arnica plant products has caused severe gastroenteritis, rapid heart rate, muscle weakness and death. This concerns swallowed herbal arnica, not homeopathic dilutions.
- LimitedCase reports: arnica dermatitis has occurred in people handling the flowers. In trials, side effects on arnica gel were about as common as on ibuprofen gel.
What people take it for, and what was found
Shown to help1
Hand osteoarthritis pain: topical herbal arnica
One trial found arnica gel eased hand osteoarthritis pain about as much as ibuprofen gel over 21 days in 204 adults, with no placebo group.
The numbers and sources
- Effect
- In 204 patients with hand osteoarthritis, an arnica gel (50 g tincture per 100 g) and 5% ibuprofen gel for 21 days did not differ in pain, hand function or any secondary outcome [11]. A Cochrane review of topical herbal treatments found one such trial in 174 people. Arnica gel reduced pain by 3.8 points more than ibuprofen on a 100-point scale (95% CI -10.1 to 2.5) [12].
- Population
- Adults with hand osteoarthritis [11][12].
- Sources
- [11], [12]
- Caveats
- The comparison was with ibuprofen gel, with no placebo group [11].
Mixed results2
Bruising: topical herbal arnica
Small trials found opposite results: 20% arnica ointment improved laser bruises more than petrolatum, while arnica gel did no better than its base after laser treatment.
The numbers and sources
- Effect
- In healthy volunteers with standard laser-induced bruises, 20% arnica ointment twice a day for 2 weeks improved bruise ratings more than white petrolatum (P 0.003) and more than 1% vitamin K with retinol, but not more than 5% vitamin K [5]. In 19 patients treated with laser for facial veins, arnica gel did not differ from the gel base on one side of the face, whether applied before (P 0.496) or after (P 0.359) treatment [6]. The procedure review counted 2 topical arnica trials [4].
- Population
- Healthy adults aged 21 to 65 [5]. 19 laser patients [6].
- Sources
- [5], [6], [4]
- Caveats
- The ointment trial's abstract does not give the number of volunteers [5]. Both trials are small and reached different results.
Muscle soreness: topical herbal arnica
Small trials found opposite results: arnica cream raised pain at 24 hours after calf raises, while topical arnica lowered pain at 72 hours after downhill running.
The numbers and sources
- Effect
- In 53 adults after calf raises, legs treated with arnica cream had more pain at 24 hours than legs treated with placebo cream (3.04 against 2.36, p < 0.005), with no difference later [9]. In 20 trained men after downhill running, topical arnica lowered pain and muscle tenderness at 72 hours, with no effect on performance or blood markers of muscle damage [10].
- Population
- 53 adults [9]. 20 well-trained men [10].
- Sources
- [9], [10]
- Caveats
- Two small trials with opposite findings.
Not shown to help2
Bruising and swelling after surgery: homeopathic arnica
Not shown to reduce bruising or swelling after surgery more than placebo when homeopathic arnica is taken by mouth. Most trials were flawed.
The numbers and sources
- Effect
- Across 18 placebo comparisons of homeopathic arnica in surgery, the pooled effect was Hedges' g 0.18 (95% CI -0.007 to 0.373, p 0.059). Against active comparators the effect was g 0.26, driven by nonrandomized studies and close to zero in randomized ones [1]. An earlier review of 8 placebo-controlled trials, most with severe methodological flaws, found on balance no benefit over placebo [2]. In a rhinoplasty trial, 9 patients on oral arnica had 32.9% less bruise area than 13 on placebo at day 7 (P 0.097, with significance set at P under 0.1) [3]. A review of procedure trials counted 11 trials of oral arnica and judged the data insufficient [4].
- Population
- Surgical patients in 28 comparisons [1]. 8 placebo-controlled trials [2]. 22 rhinoplasty patients [3].
- Sources
- [1], [2], [3], [4]
- Caveats
- All of these tested homeopathic dilutions taken by mouth, not herbal arnica. The procedure review's abstract does not state the dilutions used [4]. The rhinoplasty trial was small and used a looser significance threshold [3].
Muscle soreness: homeopathic arnica
Limited evidence: in 400 runners homeopathic arnica did not ease soreness over placebo, while a smaller marathon trial found less soreness right after the race.
The numbers and sources
- Effect
- In 400 long-distance runners, mean 2-day soreness scores were 45.2 mm on Arnica 30X and 41.0 mm on placebo (95% CI 8.81 mm favoring placebo to 0.51 mm favoring arnica) [7]. In 82 marathon runners pooled from two trials, soreness right after the race was lower on Arnica D30 (P 0.04), and muscle enzyme levels did not differ [8].
- Population
- 519 runners enrolled, 400 analyzed [7]. 82 Oslo Marathon runners [8].
- Sources
- [7], [8]
- Caveats
- Both are homeopathic dilutions taken by mouth. The larger trial found no benefit [7].
Doses studied
Homeopathic trials used Arnica 30X [7] and Arnica D30, five pills morning and evening from the evening before a marathon to three days after it [8]. Topical trials used 20% arnica ointment twice a day for 2 weeks [5] and an arnica gel of 50 g tincture per 100 g for 21 days [11].
Risks
Reported risks2
Poisoning from eating plant arnica
Case reports: eating arnica plant products has caused severe gastroenteritis, rapid heart rate, muscle weakness and death. This concerns swallowed herbal arnica, not homeopathic dilutions.
The numbers and sources
- Effect
- An expert panel safety report states that eating products containing Arnica montana has caused severe gastroenteritis, nervousness, rapid heart rate, muscle weakness and death [13]. Among 86 calls to a poison center about herbal teas taken to induce abortion, multiple organ failure occurred in people who had taken rue, Carachipita, arnica or burdock [14].
- Population
- Published reports reviewed by the panel [13]. Callers to the Montevideo Poison Centre from 1986 to 1999 [14].
- Sources
- [13], [14]
- Caveats
- This concerns herbal arnica swallowed as the plant or extract, not homeopathic dilutions. Neither source gives a rate, and the poison center cases often involved several plants [14].
Skin allergy and side effects of topical arnica
Case reports: arnica dermatitis has occurred in people handling the flowers. In trials, side effects on arnica gel were about as common as on ibuprofen gel.
The numbers and sources
- Effect
- A delayed allergic skin reaction, arnica dermatitis, has been reported in people who handle arnica flowers, while clinical patch tests of extracts did not cause irritation or sensitization [13]. In the hand osteoarthritis trial, adverse events occurred in 4.8% on arnica gel and 6.1% on ibuprofen gel [11]. The Cochrane review gave 13% against 8% (RR 1.65, 95% CI 0.72 to 3.76) [12]. One patient in the rhinoplasty trial had mild itching and rash on oral arnica [3].
- Population
- People handling arnica [13]. Adults with hand osteoarthritis [11][12]. Rhinoplasty patients [3].
- Sources
- [13], [11], [12], [3]
- Caveats
- The two hand osteoarthritis figures differ, and neither difference was significant [11][12].
Claims tested and not found
- That homeopathic arnica reduces muscle soreness after long-distance running. In 400 runners, soreness scores did not differ from placebo [7].
- That topical arnica eases muscle pain after calf exercise. Pain was higher on arnica at 24 hours and the same later [9].
- That topical arnica gel prevents or speeds laser bruising. Bruise scores did not differ from the gel base [6].
Sources
- Gaertner K, Baumgartner S, Walach H. Is Homeopathic Arnica Effective for Postoperative Recovery? A Meta-analysis of Placebo-Controlled and Active Comparator Trials. Frontiers in Surgery. 2021. https://doi.org/10.3389/fsurg.2021.680930
- Ernst E, Pittler MH. Efficacy of homeopathic arnica: a systematic review of placebo-controlled clinical trials. Archives of Surgery. 1998. https://doi.org/10.1001/archsurg.133.11.1187
- Chaiet SR, Marcus BC. Perioperative Arnica montana for Reduction of Ecchymosis in Rhinoplasty Surgery. Annals of Plastic Surgery. 2016. https://doi.org/10.1097/SAP.0000000000000312
- Ho D, Jagdeo J, Waldorf HA. Is There a Role for Arnica and Bromelain in Prevention of Post-Procedure Ecchymosis or Edema? A Systematic Review of the Literature. Dermatologic Surgery. 2016. https://doi.org/10.1097/DSS.0000000000000701
- Leu S, Havey J, White LE, et al. Accelerated resolution of laser-induced bruising with topical 20% arnica: a rater-blinded randomized controlled trial. British Journal of Dermatology. 2010. https://doi.org/10.1111/j.1365-2133.2010.09813.x
- Alonso D, Lazarus MC, Baumann L. Effects of topical arnica gel on post-laser treatment bruises. Dermatologic Surgery. 2002. https://doi.org/10.1046/j.1524-4725.2002.02011.x
- Vickers AJ, Fisher P, Smith C, et al. Homeopathic Arnica 30x is ineffective for muscle soreness after long-distance running: a randomized, double-blind, placebo-controlled trial. The Clinical Journal of Pain. 1998. https://doi.org/10.1097/00002508-199809000-00009
- Tveiten D, Bruset S. Effect of Arnica D30 in marathon runners. Pooled results from two double-blind placebo controlled studies. Homeopathy. 2003. https://doi.org/10.1016/j.homp.2003.03.001
- Adkison JD, Bauer DW, Chang T. The effect of topical arnica on muscle pain. Annals of Pharmacotherapy. 2010. https://doi.org/10.1345/aph.1P071
- Pumpa KL, Fallon KE, Bensoussan A, Papalia S. The effects of topical Arnica on performance, pain and muscle damage after intense eccentric exercise. European Journal of Sport Science. 2014. https://doi.org/10.1080/17461391.2013.829126
- Widrig R, Suter A, Saller R, Melzer J. Choosing between NSAID and arnica for topical treatment of hand osteoarthritis in a randomised, double-blind study. Rheumatology International. 2007. https://doi.org/10.1007/s00296-007-0304-y
- Cameron M, Chrubasik S. Topical herbal therapies for treating osteoarthritis. Cochrane Database of Systematic Reviews. 2013. https://doi.org/10.1002/14651858.CD010538
- No authors listed. Final report on the safety assessment of Arnica montana extract and Arnica montana. International Journal of Toxicology. 2001. https://doi.org/10.1080/10915810160233712
- Ciganda C, Laborde A. Herbal infusions used for induced abortion. Journal of Toxicology: Clinical Toxicology. 2003. https://doi.org/10.1081/clt-120021104