You may think that when you get a bruise there’s nothing to do but wait for it to heal.

So you may be surprised to learn that a common herb can help bring those purples and greens back to their natural shade, and even reduce pain and inflammation in the process.

Available research suggests that arnica can help reduce bruising. You can apply arnica to your skin in the form of gels or lotions. It’s also sometimes taken in a homeopathic dose by mouth.

The scientific name for arnica is Arnica montana. It’s also known as:

  • Mountain tobacco
  • Leopard’s bane
  • Wolf’s bane
  • Mountain arnica

The flower of the arnica plant has been used for hundreds of years for its apparent benefits. Traditionally, it’s been used to reduce:

  • pain
  • swelling
  • bruising

Arnica for pain

Arnica is often used for pain management, but research on its effectiveness is mixed.

A 2016 review of studies found that arnica was effective at easing pain after surgery compared with a placebo. It concluded that homeopathic arnica could be a viable alternative to nonsteroidal anti-inflammatory drugs (NSAIDs), depending on the condition being treated.

A 2021 review indicated arnica in gel/cream or extract form might aid in chronic pain management.

However, one 2010 double-blind study looked at the effects of arnica on muscle pain in 53 subjects. It found that, when compared with a placebo, arnica lotion actually increased leg pain 24 hours after atypical muscle use.

Arnica for bruising and swelling

Another 2021 review indicated that homeopathic arnica had a small effect in mitigating excessive hematoma or bruises after surgeries compared with a placebo.

A 2020 systemic review of 29 articles suggested that arnica might reduce ecchymosis (discoloration of the skin usually caused by bruising) if used after rhinoplasty and facelifts or facial procedures.

A 2017 analysis of 11 trials of more than 600 patients from the same year suggested that arnica, combined with cold compression and tape, could lower eyelid bruising and swelling after rhinoplasties.

Still, a 2021 report by the American Academy of Ophthalmology (AAO) did not support the use of arnica to reduce ecchymosis following oculofacial surgeries.

More research is needed to confirm the effectiveness of arnica for pain, bruising, and swelling, as well as appropriate doses.

Arnica comes in the following forms:

You can find many arnica products online, but experts say you’ll want to speak with a healthcare professional about reputable brands.

Jennifer Gordon, MD, a board-certified dermatologist with Westlake Dermatology in Austin, suggests applying gels and lotions to the affected area three to four times per day or as directed by your healthcare professional.

Alexander Zuriarrain, MD, FACS, a quadruple board-certified plastic surgeon with Zuri Plastic Surgery, recommends avoiding your eyes, since arnica lotions can cause burning in that area.

Gordon says patches should be applied near the site of the pain as directed. Zuriarrain notes people can typically use patches twice daily. Usage instructions will be on the box.

People using tissue salts will want to dissolve the recommended amount into the bath to soak and then hop in the tub, Gordon says. Again, you’ll find the recommended amount on the box and can consult with a healthcare professional first about dosage.

Gordon recommends speaking with your doctor and pharmacist about reputable brands and dosages, particularly for oral arnica products like tablets and teas.

Once a product has been approved by your doctor and pharmacist, carefully follow the directions on the label for dosing and brewing teas.

Arnica is listed as a poisonous plant by the Food & Drug Administration (FDA) and is considered unsafe for oral ingestion. However, homeopathic remedies are extremely diluted, and most studies on homeopathic arnica have found it safe for use.

The FDA hasn’t approved any homeopathy remedies, including arnica, and hasn’t evaluated any arnica remedy for effectiveness or safety. Always talk with your doctor before you start any complementary treatments, including homeopathic arnica.

A 2017 review noted that arnica plant extracts have been found to have several beneficial properties including:

  • antibacterial
  • antifungal
  • anti-inflammatory
  • antioxidant
  • antitumor
  • immunomodulatory

Various parts of the plant also contain a wide range of beneficial chemical compounds, like:

However, more high quality research is needed to confirm this, as well as how to best reap these benefits. This is especially true because ingesting arnica is considered poisonous.

As mentioned, arnica is considered unsafe for ingestion by the FDA. Consuming arnica can lead to:

  • diarrhea
  • vomiting
  • nausea
  • internal bleeding

It’s possible to overdose even on homeopathic arnica.

A 2013 study documents the case of an individual who overdosed on homeopathic arnica and experienced vomiting and a temporary loss of vision.

According to the Memorial Sloane Kettering Cancer Center, you should avoid ingesting arnica if you’re pregnant or breastfeeding, as it can harm the baby. In one case, a person drank arnica tea, and her 9-month-old nursing baby became lethargic 48 hours later. The baby was treated and his symptoms eventually disappeared.

You also shouldn’t ingest arnica if you’re on warfarin (Coumadin) or any blood-thinning medication. Research from 2000 indicated that alternative therapies, including arnica, could interact with warfarin.

Topical use of arnica can lead to contact dermatitis in some people, so do a patch test before applying arnica lotion to a large area of the skin. If you’re allergic to sunflowers or marigold, it’s likely that you’re also allergic to arnica.

Don’t ingest arnica if you’re pregnant, breastfeeding or chestfeeding, or taking blood-thinning medication. Don’t apply arnica to sensitive skin or open wounds. Always do a patch test before applying arnica lotion to the skin.

Want to learn more? Get the FAQs below.

Does arnica interact with medications?

A study from 2000 confirmed that, when ingested, arnica could interact with blood-thinning medications, such as warfarin. This is because arnica could make anticoagulants (blood thinners) more effective.

How much arnica should I take for bruising?

There isn’t an evidence-based consensus on how much arnica to take for bruising.

It “depends on which product and how it’s dosed,” Gordon says. “The bottle will tell you how and how much to use. If you know you have surgery coming, we often recommend starting 2 weeks prior to the surgery.”

Is arnica for bruising or swelling?

More research is needed to definitively say arnica is effective at treating bruising or swelling. Data is currently mixed.

One 2021 review indicated arnica was slightly more effective at reducing bruises than a placebo, and an analysis suggested it could lessen eyelid bruising post-rhinoplasty if combined with cold compresses.

But the AAO doesn’t endorse using arnica to lower ecchymosis after oculofacial surgeries.

How do you get rid of a bruise in 24 hours?

Zuriarrain says it’s important to manage expectations when trying to get rid of a bruise.

“It is not logical that a bruise will resolve within 24 hours,” he says. “It takes the body a longer time frame to heal from a bruise, as it’s a collection of blood vessels that burst and need to be dissolved by the body’s cells.”

Zuriarrain says people may see faster improvement in the bruise quality by using a combination of arnica and massage therapy.

According to research, arnica might be able to reduce bruising and swelling when applied topically or taken as a homeopathic treatment in pill form.

Arnica may also have a range of other useful medical benefits. Check with your doctor before using any type of arnica if you have any concerns.