Comfrey is a shrub growing in parts of Europe, Asia, and North America. While it may help with wounds and joint pain, studies warn against eating it due to a risk of liver damage and cancer.

Comfrey can grow up to 5 feet tall. It produces clusters of purple, blue, and white flowers, and it’s famous for its long, slender leaves and black-skinned roots.

The root and leaves of the comfrey plant have been used in traditional medicine in many parts of the world. In Japan, the plant has been harvested and used as a traditional treatment for over 2,000 years. It was originally called “knitbone” and people used it to treat:

  • muscle sprains
  • bruises
  • burns
  • joint inflammation

Europeans have also used comfrey to treat inflammatory conditions, such as arthritis and gout. Some traditional healers have also used it to treat diarrhea and other stomach ailments.

The roots of leaves of the comfrey plant contain chemical substances called allantoin and rosmarinic acid. Allantoin boosts the growth of new skin cells, while rosmarinic acid helps relieve pain and inflammation. Extracts are still made from the roots and leaves and turned into ointments, creams, or salves. These solutions typically have a comfrey content of 5 to 20 percent.

While comfrey is well-known for its health benefits, it also poses some risks. It contains compounds that can harm your liver. It may also be carcinogenic. As a result, many countries have banned the sale of oral comfrey preparations. Many experts also advise against using topical comfrey on open wounds.

But comfrey may be acceptable for short-term use on your skin and closed wounds. You can purchase topical comfrey preparations from many health stores. Talk to your doctor before using them to learn more about the potential benefits and risks.

People still use comfrey as an alternative remedy for joint and muscle pain, as well as closed wounds. It’s available at many health stores and pharmacies as

  • ointments
  • creams
  • other topical solutions
  • salves that also contain other herbs, such as aloe and goldenseal


Some clinical research supports the claim that comfrey has wound-healing powers. For example, a research review published in the journal Complementary Therapies in Medicine found some evidence that comfrey can help heal abrasion wounds. The authors note that topical applications of comfrey appear to be safe, but more research is necessary to learn about the potential risks and side effects of using comfrey on your skin and wounds.

Joint pain

According to the same research review, results also suggested that comfrey can help treat osteoarthritis, as well as some injuries, such as ankle sprains. A study reported in Phytotherapy Research also suggests that creams containing comfrey root can help relieve upper and lower back pain.

Historically, some people have eaten comfrey leaves as a vegetable. Traditional healers have also used oral preparations of comfrey to treat stomach issues, such as ulcers, colitis, and diarrhea. You can also drink dried comfrey root and leaves as tea.

Today, eating or taking any form of comfrey by mouth isn’t recommended. It’s considered unsafe, due to the pyrrolizidine alkaloids that comfrey contains. These are dangerous chemicals that can cause cancer, severe liver damage, and even death when you consume them. For this reason, the Food and Drug Administration and European countries have banned oral comfrey products.

Modern scientific studies have found some evidence to support comfrey’s use in treating minor wounds and joint pain, but oral preparations of the plant have also been linked to liver damage and cancer. You should never take comfrey by mouth. You should also avoid using it on open wounds.

Comfrey may be safe to apply to your skin or closed wounds for short periods. Always talk to your doctor before using products that contain it. They can help you understand the potential benefits and risks. They may advise you to avoid comfrey, especially if you’re:

  • a child
  • an older adult
  • pregnant
  • breast-feeding
  • someone with a history of liver disease