Arnica for Bruises and Sore Shoulders: What's Real

A bruise forms when small blood vessels under the skin leak after a bump. The blood is gradually cleared away, which is thought to be why a bruise changes colour over several days.

Shoulder soreness is a different matter. It can come from muscles, tendons, the lining of the joint or nerves. Only a clinician can tell which one is involved. Many people try a remedy first and then wonder why it did not help. The better first question is what is causing the pain.

Arnica (Arnica montana) is a yellow-flowered plant. It has a long history of use on bruises and aching muscles. Modern research on those uses is limited, at least in the sources we reviewed.

For the wider picture, see alternative remedies for shoulder pain: what the evidence says about each.

• Evidence for most herbal and supplement remedies for muscle and joint pain is insufficient. The US National Center for Complementary and Integrative Health says this about many supplements in general [R20].
• There isn't strong research on arnica for shoulder pain specifically, so the closest evidence is that general finding.

Evidence level for arnica and shoulder pain: insufficient, as far as the sources we reviewed show. If you want to look at newer studies, ask your clinician or pharmacist to help you read them.

1. Check for red flags first. If anything in the box below applies, get assessed before you try a remedy.
2. Rest the sore area for now. Seated rest is fine. Avoid any movement that causes sharp pain.
3. Watch a bruise. Note its size and colour each day. If it grows, becomes very swollen or you feel unwell, see a clinician.
4. If you choose to try arnica, follow the label, use it only as directed and stop if your skin reacts.
5. Ask your pharmacist or doctor first if you take blood thinners or any other regular medication.
6. Keep gentle, seated movement in your plan. Try slow arm reaches while seated, within a range that feels comfortable. Stop if the pain rises sharply. Ask your clinician what is safe for your shoulder before you start anything new. Once cleared, the routine library has seated ideas.