Comfrey: A Common Plant With Uncommon Healing Capabilities

Nicknamed “knit-bone,” comfrey has the superpower of stimulating the body to rapidly heal wounds and mend tissues, bones, and cartilage.

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When Molly Maples suspected a broken little toe after jamming in into a door, she discovered that conventional medical advice was limited to icing, elevating, and using pain medication.

Dissatisfied with these options, Ms. Maples sought relief in traditional remedies, applying a poultice of comfrey and plantain weed to her toe nightly. “My toe completely healed in under four weeks,” she told The Epoch Times. Typically, it takes 4-6 weeks for a baby toe to heal.

In orthopedics, comfrey emerges as a time-honored alternative to the norm of precise treatments such as bone-setting and joint replacements. Commonly known as “knit-bone,” this herb has been revered for generations for its ability to mend bones and alleviate joint pain, reminding us that even in modern medicine, nature still has a role to play.

Comfrey: Nature’s Bone Healer

Comfrey, which has the scientific name Symphytum officinale, has a rich history in folk medicine, recognized for its medicinal qualities since the Middle Ages throughout Europe and Asia. Comfrey has been widely used to decrease inflammation and speed up the recovery of bruises, sprains, and fractures.

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Amelia South, a trained herbalist and the owner of Black Sun Farm, highlighted comfrey’s effectiveness in orthopedic care to The Epoch Times.

“Comfrey is absolutely one of my top five herbs that I never want to go without,” she said. “It has helped me heal a sprained ankle on several occasions, sprained wrists, and numerous bruises.”

The herb also has a variety of other medicinal uses. Comfrey has been used to treat respiratory ailments such as bronchitis, tonsillitis, and pneumonia by soothing inflammation and promoting lung moisture. Additionally, it is believed to support digestive health, aiding in blood sugar control and enhancing digestion through pepsin secretion.

Nancy Shirley, an author with publications on comfrey, including “Cultivation of Comfrey; Medicinal and Food Uses for People,” extols the herb’s medicinal virtues.

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“Comfrey’s nickname, ‘knit bone,’ is highly appropriate as one of its constituents (allantoin) actually causes cellular proliferation,” she said in an email to The Epoch Times. This compound stimulates the body to produce new cells rapidly, which is beneficial for healing wounds and mending tissues, bones, and cartilage.

The roots of comfrey are rich in phenolic acids such as rosmarinic, caffeic, and chlorogenic acids. These substances reduce inflammation and possess potent antioxidant properties that protect cellular integrity and promote skin health.

Advanced extraction techniques, such as enzyme-ultrasonic assistance, have been used to isolate polysaccharides—complex sugars with anti-inflammatory properties—from comfrey, underscoring the plant’s role in modern therapeutic applications.

What Does the Research Say?

Research into comfrey’s effectiveness, particularly in treating musculoskeletal conditions, shows promise. Various studies and clinical trials have evaluated its potential to heal sprains, bruises, and fractures.

Research published in the British Journal of Sports Medicine emphasized the effectiveness of comfrey root extract ointment for acute back pain. The trial, involving 120 patients, compared the ointment’s effects with a placebo, administered three times daily for five days. Success was measured by the reduction in pain intensity during movement.

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The results demonstrated a substantial reduction in pain for the comfrey group—about 95 percent, versus 38 percent in the placebo group.

The researchers concluded: “Comfrey root extract showed a remarkably potent and clinically relevant effect in reducing acute back pain. For the first time a fast-acting effect of the ointment (1 h) was also witnessed.”

A 2020 study in the Journal of Ethnopharmacology examined comfrey’s effect on bone cell development from stem cells in human bone marrow. The study found that comfrey, particularly in its concentrated liquid form, significantly enhances bone formation, evidenced by elevated levels of crucial enzymes and markers for bone health.

Additional research published in Frontiers in Pharmacology demonstrates comfrey’s anti-inflammatory properties. The study focused on comfrey root extract and found that it stops a key process that causes inflammation in the body by blocking a crucial protein involved in this response.

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A 2011 study investigated the effect of comfrey root extract and tannic acid on knee osteoarthritis. In the randomized, double-blind trial, 43 patients applied creams containing either the extract or a placebo three times daily for six weeks. The comfrey groups experienced significant improvements in pain, stiffness, and physical function compared with the placebo group, with only minor skin irritations noted as side effects, which resolved swiftly.

A comprehensive review in Complementary Therapies in Medicine analyzed 26 studies, including 13 randomized controlled trials, five non-randomized trials, and eight observational studies. The review assessed comfrey’s effectiveness in managing conditions such as ankle distortions, back pain, wounds, and osteoarthritis.

The findings suggested potential benefits, though the evidence was limited by inconsistent reporting, leading to possible biases. Adverse events were rare and generally minor. The review concluded that although topical comfrey appears safe and promising for certain conditions, more thorough studies are necessary.

The Comfrey Safety Debate

The safety of comfrey, especially concerning its content of pyrrolizidine alkaloids, continues to be a contentious issue within the herbal supplement community. Pyrrolizidine alkaloids, found in more than 6,000 plants, act as a defense against insects and plant-feeding animals.

The primary concern is the potential for liver damage resulting from the oral consumption of these alkaloids. Although liver risks are well-documented with various pharmaceuticals and substances such as alcohol, the specific dangers associated with comfrey’s pyrrolizidine alkaloids continue to undergo intense scrutiny.

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In 2001, the U.S. Food and Drug Administration (FDA) issued a warning about the use of comfrey in dietary supplements, advising against its internal use. They cited liver damage in animals, and potential harm in humans, linking these alkaloids to veno-occlusive disease, a severe liver condition.

The FDA noted that no direct cause-and-effect relationship has been confirmed in humans because of the absence of human trials. Nonetheless, the adverse effects observed were consistent with risks known from animal studies, prompting the FDA to request that manufacturers withdraw products containing comfrey from the market. The Federal Trade Commission also acted against companies marketing comfrey products, emphasizing that even topical use requires caution and proper consumer warnings.

Despite these warnings, comfrey has been used internally for millennia in traditional medicinal practices. Brendan Kelly, a Chinese medicine practitioner with nearly three decades of experience in herbalism, highlights the lack of targeted research, saying, “I’m not aware of any studies specifically investigating comfrey’s risks to the human liver.”

A 2021 study on pyrrolizidine alkaloids found that although they “have potential health risks to humans, they also demonstrate many beneficial pharmacy properties, such as antibacterial, antifungal, anti-inflammatory, anticancer, and antivirus properties.”

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Many herbalists assert that comfrey is safe for occasional use and is not hazardous when used in moderation. However, some have ceased using it altogether. Amelia South mentioned that occasional consumption as a tea, particularly using the whole herb, may be beneficial because of its synergistic medicinal components. Nonetheless, she recommends against its use for those with existing liver conditions.

Practical Guidelines for Safe Use

Comfrey is best known for its external use, typically as a poultice, salve, or oil. To create a comfrey poultice, blend fresh leaves or roots into a paste, place it on a clean cloth, and apply it to the affected area. Alternatively, high-quality comfrey salves are available for purchase at reputable health stores.

If one uses comfrey to aid in healing a fracture, the bone must be properly set first. Comfrey promotes rapid healing, and if applied to a misaligned bone, it could cause the bone to heal incorrectly. Therefore, comfrey should be used only after a professional correctly aligns the bone.

Although comfrey has significant healing properties, it should not be applied to large, open wounds. Avoiding such application prevents rapid skin closure that could encase bacteria or debris within the wound.

When using comfrey, it’s crucial to adhere to treatment duration guidelines. Use of topical applications should not exceed six weeks, and use of internal applications, such as teas or supplements, should be limited to two weeks post-injury.

Ms. South said, “For helping to heal a broken bone, drinking comfrey tea for two weeks post-injury can be beneficial, followed by external applications like salves or oils.”

Ms. Shirley recommends seeking personalized guidance from a health care professional, as not all herbs are appropriate for every individual. It is essential to consult with health care experts before adding comfrey to any treatment regimen, particularly for internal use. Adhering to these guidelines ensures that users can safely and effectively benefit from comfrey’s therapeutic properties.