Comfrey Benefits, Uses and Risks - Dr. Axe

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Comfrey Herb to Soothe Muscles, Joints & Skin



For those familiar with natural medicine and chronic pain, comfrey is likely on your list of remedies. This herb has been used for centuries to treat a variety of pain- and inflammation-related issues.

Among its clinical uses, comfrey can help relieve pain, reduce inflammation of muscles and joints, speed the healing of bruises and contusions and potentially aid in the treatment of fibromyalgia.

In the U.K., researchers found that practitioners prescribed it in about 15 percent of all consultations regarding tendon, ligament and muscle problems, fractures and wounds.

Although it was commonly used internally for many years, the U.S. Food and Drug Administration, as well as governing bodies around the globe, banned the use of dietary supplements containing comfrey and advised against any internal usage in 2001. Studies have found that it contains pyrrolizidine alkaloids, which are toxic to the liver.

Comfrey is still highly useful for external uses. It can help serve as a powerful pain reliever and anti-inflammatory. In fact, it can even help speed the healing of wounds. Let’s look at how it works.

What Is Comfrey?

The common comfrey plant is known in Latin as Symphytum officinale and displays a “hairy” exterior. It grows as a root stick with branches coming from the stalk and only gets to about 2–3 feet tall. Some varieties produce yellow or purplish flowers alongside the broad, fuzzy leaves. The most commonly grown species is Russian comfrey (Symphytum x uplandicum).

Comfrey plants can grow in almost any climate or soil and prefer the shade. Medicinally, most folk remedies suggest using the leaves, although the roots also carry significant benefits when used as well.

In large quantities, mucilage (a gelatin plant-derived compound) is the main component of comfrey.


1. Can relieve muscle and joint pain

A large review released in 2013 about the medicinal uses of comfrey stated:

It is clinically proven to relieve pain, inflammation and swelling of muscles and joints in the case of degenerative arthritis, acute myalgia in the back, sprains, contusions and strains after sports injuries and accidents, also in children aged 3 years and older.

However, available scientific evidence seems to back it up. In multiple studies, comfrey application improves the healing and pain response of bruises, sprains and painful muscles and joints, particularly related to exercise.

In a single-blind, randomized clinical trial of 164 participants comparing the efficacy of comfrey against a common NSAID (non-steroidal anti-inflammatory drug) used for ankle sprains and pain, it performed better than diclofenac gel, leading the researchers to state their encouragement that this natural product functions as a safe and effective alternative to the standard treatment.

2. Effective for lower back pain relief

Searching for lower back pain relief can be an exhausting and daunting task for the 31 million Americans struggling with this pain at any given time. However, comfrey may offer an alternative method for this chronic condition.

Two double-blind, randomized controlled clinical trials showed significant pain relief when compared with a placebo on an external application of comfrey root extract gel on the back.

3. May aid in reducing arthritis pain

An astounding 1 in every 5 people in the U.S. suffer from arthritis pain. Worn-down cartilage and connective tissue cause bones to rub together and cause chronic pain.

Because of the possible side effects involved with most medications for arthritis, such as heartburn, stomach ulcers, increased risk of heart attack or stroke, cataracts, bone loss and more, many people seek alternative remedies for relieving their pain in a safe way.

It turns out that using a topical comfrey ointment or poultice can help to significantly decrease the pain associated with arthritis. Various study reviews have seen results consistent, in some cases, with topical NSAIDs and even arnica, all without any negative side effects.

For arthritis relief, try creating a poultice of comfrey with pain-relieving essential oils such as peppermint oil and applying it to the painful areas two to three times a day.

Please note: comfrey should only be used topically up to 10 consecutive days, in order to avoid bioaccumulation. There are no studies showing a danger of this, but we take this precaution to stay on the safe side.

About comfrey - Dr. Axe

4. Natural fibromyalgia remedy

Because fibromyalgia is associated with pain in various parts of the body, comfrey application might help to offer some relief. Again, stick to no more than 10 consecutive days of application. And limit use to four to six weeks per year.

If you suffer from fibromyalgia pain, remember that your best option is to seek a multi-targeted approach to address whatever the root cause of this pain may be. Adjusting lifestyle to lose extra weight, eliminating problematic food ingredients like excitotoxins and eating anti-inflammatory foods may offer some additional relief.

5. Speeds wound healing

Comfrey contains an ingredient called allantoin, which aids the regrowth of skin, along with rosmarinic acid and tannins. Allantoin has been developed as an approved medication for over-the-counter skin treatment for a variety of skin issues.

That’s a likely reason it may help wounds to heal faster. One folk term for it is “knitbone” because it was believed to activate the healing of bones.

While bone regrowth has not been proven scientifically as a benefit, researchers have noted an improvement in collagen production and wound healing when applying topically.

For safety, never use comfrey on an open wound. If you want to see how it works for your own wounds, wait until the wound has totally closed before applying it.

6. Lessens skin irritations

Probably also due, in part, to the presence of allantoin in comfrey, another use in folk medicine for it is the soothing of inflamed, irritated skin.

Two controlled clinical studies saw a healing effect on irritation caused by UV-B rays (a mild sunburn) was equal to or greater with comfrey than diclofenac, one of the more often used over-the-counter medications used to soothe skin. (15)

In another study, researchers purposefully irritated the skin of healthy young adults and then tested a liquid extract of comfrey on the skin. They found that topical applications of “comfrey extract may have a great application in the treatment of skin irritation.” (16)


In folk medicine, comfrey was a common feature among those in Europe. Known as “knitbone,” it was used for everything from the speeding of bone growth to nausea to acne relief. Historically, it has been prescribed to remedy diarrhea and for lung issues.

It can be used in gardening as a fertilizer as well as an herb.

Comfrey products such as poultices, ointments and salves have been used as herbal remedies because of the plant’s ability to reduce inflammation and urge healing. The root has also been used in the past as a decoction to help gastrointestinal problems such as diarrhea. However, using it internally is not recommended.

It’s not just humans who can benefit from comfrey — in 2014, researchers in Taiwan looked at the ability of its leaves to alleviate UV damage to the fins of zebrafish, suggesting it as a potential development for an agent to protect zebrafish embryos from future damage.

There is also preliminary research on the development of comfrey extract in creating an anticancer drug to combat prostate cancer. An animal study found very promising results — although it’s very important to note here that this does not mean you should ever ingest it. Controlled research in a lab of a chemically-extracted component of the plant is extremely different than just eating or drinking the substance.

How to Use

In most circumstances, the most effective way to use comfrey is in a salve or poultice. This is then applied to the skin. For example, comfrey oil is a key ingredient in a DIY bruise cream with arnica and bilberry.

You can purchase comfrey oil as an infusion with olive oil. Or, you can create your own oil (also known as comfrey balm)by simmering olive oil (or another carrier oil) and comfrey roots and leaves.  Use this oil to treat minor closed wounds and aches.

Many people simply use fresh or dry comfrey leaves directly on the skin, depending on the type and severity of pain they have. Perhaps due to the high mucilage content, its leaves do not dry as fast as most herbs. But give them time, and you’ll be excited about the results.

Since comfrey isn’t widely available outside of Europe, if you live in another area but would like to grow your own plants, it’s quite simple. After buying some seeds and (preferably) planting them in a shaded area, you will most likely see them grow quickly.

Fortunately, it is a fairly “non-invasive” plant because it doesn’t put down long roots and doesn’t set seed as it grows. This perennial is best harvested before its flowers bloom.

Precautions and Side Effects

Like I’ve mentioned, it’s imperative that you do not ingest comfrey, whether in fresh or tea form (or any other method).

Comfrey is toxic because it contains a substance called pyrrolizidine alkaloids (PAs). The main concern with these PAs are liver toxicity. PAs can cause veno-occlusive disease of the liver, a blockage of microscopic veins within the liver that can lead to cirrhosis, liver failure and/or cancer.

Some efforts have been made to create purified comfrey extract or tea free of pyrrolizidine alkaloids. Both of these have resulted in even worse side effects than before.

There is also at least one reported case that comfrey tea was linked to a second-degree heart blockage of a female patient in the U.K.

While there have been no cases to date of toxicity resulting from epidermal application, a minuscule amount of PAs do pass through the skin when you use it. Because of this, it’s best to use it for no more than 10 days in a row and only for a maximum total of 4–6 weeks each year to avoid any negative side effects.

Never use comfrey on an open wound or broken skin. People with liver disease, cancer or a history of alcohol abuse should also avoid even the external use of it.

Most sources agree that comfrey is safe externally for children over 3 years of age. But others recommend never using it for children under the age of 18. Pregnant or breastfeeding women should not use it.

Final Thoughts

  • Comfrey is a traditional herbal treatment for muscle and joint pain. It helps to reduce painful inflammation and soothe the skin as well as help heal bruises.
  • This perennial herb grows mainly in the United Kingdom. But it can grow in most climates, although the plant does prefer shaded environments.
  • Using comfrey as a poultice or simply by using its dried leaves on the skin, you may find relief from pains relating to conditions like ankle sprains, muscle aches, arthritis and fibromyalgia.
  • Comfrey is not ever safe for ingestion, as it contains pyrrolizidine alkaloids that are extremely dangerous to the liver. External applications do not have the same toxic effects.
  • Pregnant/nursing women, as well as young children or those with any potential liver damage or disease, should avoid comfrey entirely.

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