Arnica percentage: what the numbers on the label mean
By Margaret Hale, Reunoa EditorialLast updated
The short answer
An arnica percentage like "15%" or "20%" tells you how much arnica extract is in the product. Homeopathic labels work differently: "1X HPUS 7%" means 7% of the product is a 1:10 dilution of tincture, and "30C" means diluted so far that no arnica is likely left. The positive bruise trial used 20% arnica ointment; homeopathic arnica didn't beat placebo after surgery.
Key takeaways
- "15%" or "20%" = share of arnica extract in the product.
- "1X" = 1:10 dilution of tincture; "7%" = share of that dilution in the product [3].
- "30C" = 1:100 diluted thirty times; effectively no arnica.
- 20% arnica ointment beat placebo on laser bruises [1].
- Homeopathic arnica didn't beat placebo after eyelid surgery [2].
Definition
Arnica percentage is the share of Arnica montana extract in a cream, gel, serum or ointment, by weight. It's the most useful number for comparing arnica products — but only when it refers to extract, not a homeopathic dilution.
Label decoder
| Label | Meaning | Arnica content |
|---|---|---|
| 20% arnica ointment | 20% of the ointment is arnica extract | High — the strength tested in the positive bruise trial [1] |
| 15% arnica | 15% extract | High |
| "With arnica" / arnica extract, no % | Unknown amount | Could be anything |
| Arnica montana 1X HPUS 7% | 7% of the product is a 1:10 dilution of tincture [3] | Much lower than 7% extract |
| 6C | Diluted 1:100 six times | Trace |
| 30C | Diluted 1:100 thirty times | Effectively none |
Why it matters
In a rater-blinded randomized trial, 20% arnica ointment helped laser-induced bruises fade faster than placebo [1]. Homeopathic arnica didn't reduce bruising compared with placebo after eyelid surgery [2], and a systematic review found mixed results overall, mostly from oral homeopathic products [4]. So when comparing products, a stated extract percentage is the best clue to how close a product is to what was tested.
Safety
- Higher extract percentages are for unbroken skin only.
- Patch-test if allergic to daisy-family plants.
- Never take non-homeopathic arnica by mouth — it can be toxic [5].
Related terms
Arnica montana · Homeopathic vs extract · Arnica cream for bruises
Frequently asked questions
What percentage of arnica is effective for bruises?
The positive trial used 20% arnica ointment. Products with a similar stated extract percentage are closest to that evidence.
Is 7% arnica gel strong?
If it says "1X HPUS 7%", it's homeopathic: 7% of the gel is a 1:10 dilution of tincture, so the arnica content is much lower than 7% extract.
What does 30C arnica mean?
It's a homeopathic dilution — diluted 1:100 thirty times — so no arnica molecules are likely to remain.
Why don't all brands list the arnica percentage?
It isn't required on cosmetic labels. If the strength matters to you, choose products that state it.
Sources
- Leu S, et al. Accelerated resolution of laser-induced bruising with topical 20% arnica: a rater-blinded randomized controlled trial. British Journal of Dermatology, 2010. PubMed 20412090
- Kotlus BS, et al. Evaluation of homeopathic Arnica montana for ecchymosis after upper blepharoplasty: a placebo-controlled, randomized, double-blind study. Ophthalmic Plastic and Reconstructive Surgery, 2010. PubMed 20683279
- Arnicare Gel — ingredients (Arnica montana 1X HPUS 7%) — Boiron / arnicare.com.
- Ho D, et al. 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. PubMed 27035499
- Arnica — About Herbs (integrative medicine database) — Memorial Sloan Kettering Cancer Center.
General information, not medical advice. Written by the Reunoa editorial team; Reunoa makes Bruise Defense & Repair Serum. See our editorial policy for how we pick sources and keep product mentions fair.