What Is Comfrey Cream?

Comfrey cream, salve, gel, and ointment

Verywell / Anastasia Tretiak

Comfrey cream combines ingredients like oils or water and glyceryl stearate with Symphytum officinale (comfrey) extracts. Comfrey is an herb in the Boraginaceae family and has small purple flowers. It's found in Europe, Asia, and North America.

Comfrey cream contains several active components (substances). These include allantoin, rosmarinic acid, and others. Some of these components are thought to speed up wound healing by stimulating new cell growth.

Comfrey can also contain echimidine, pyrrolizidine alkaloids (PAs), and symphytine, which can damage the liver, are carcinogenic (cancer-causing) and may harm a fetus.

This article discusses the uses and benefits of comfrey cream. It also covers side effects, interactions, and what to look for.

Unlike drugs, dietary supplements are not regulated in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. Choose a supplement tested by a trusted third party, such as USP, ConsumerLab, or NSF when possible.

However, even if supplements are third-party tested, it doesn't mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and to check in about any potential interactions with other supplements or medications.

Supplement Facts

  • Active ingredients: Allantoin, rosmarinic acid, flavonoids, terpenoids, triterpenes, triterpene saponins, sterols, and more
  • Alternate names: Boneset, knitbone, black wort, wallwort, and slippery root
  • Legal status: Topical (on the skin) comfrey products legal in the United States; oral products are not; in 2001, the FDA) urged oral (taken by mouth) comfrey products be removed from the market.
  • Suggested dose: 2-4 grams on the skin, three times a day
  • Safety considerations: Not studied in children less than 3 years old; not recommended during pregnancy or breastfeeding

Uses of Comfrey Cream

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Comfrey has been used medicinally for at least 2,000 years for various conditions, including bone fractures, ulcers, and gout.

Researchers have investigated the effects of comfrey cream on several health conditions. However, further, well-designed studies are needed. Here's a look at research on comfrey cream for back pain, osteoarthritis, and ankle sprains.

Back Pain

One study in 120 patients with acute upper- or low-back pain used either 4 grams (g) of comfrey root ointment or a placebo (sham treatment) three times daily for five days. Study results revealed that pain intensity during active movement decreased an average of 95.2% in the group given comfrey ointment. This was compared to 37.8% in the placebo group.

Further study is needed to confirm these results.


Comfrey cream may help treat knee osteoarthritis, according to a Cochrane review of topical herbal therapies. The review included one study of 220 people with knee osteoarthritis, a degenerative wear-and-tear joint condition. The participants were assigned three weeks of treatment with 2 g of either comfrey ointment or a placebo three times a day. Those who used the comfrey ointment experienced improvements in pain, mobility, and quality of life.

Another study found that comfrey ointment was superior to placebo in relieving pain and stiffness in osteoarthritis. The study involved 43 patients with knee osteoarthritis and a six-week treatment period.

A later study of 133 people found some evidence that a topical combination of comfrey extract and tannic acid led to reduced knee pain. However, it did not affect markers of inflammation or cartilage breakdown over 12 weeks of treatment. Using a combination product makes it challenging to know how much of the beneficial effect came from comfrey alone.

Ankle Sprains

Research has shown that comfrey cream may be helpful in the treatment of ankle sprains.

One study followed 142 patients with ankle sprains. One group used a cream with comfrey root fluid extract on the ankle while the others received a placebo. After eight days, the group that used the cream had significantly less pain than those who used the placebo.

In another study, participants with ankle sprains received either comfrey root extract cream or diclofenac gel, a nonsteroidal anti-inflammatory drug (NSAID). The ankle swelling decreased by 79.5% in the comfrey root group and 69.4% in the diclofenac group.

Additional Uses

Comfrey has also been used for the following conditions:

  • Bruises
  • Burns
  • Fractures
  • Gout (a form of arthritis)
  • Rheumatoid arthritis
  • Wounds

There is currently not enough evidence to recommend comfrey cream for any of these uses.

What Are the Side Effects of Comfrey Cream?

Using a supplement like comfrey may have potential side effects. These side effects may be common or severe.

Common Side Effects

A review of 26 clinical trials concluded that mild skin reactions were the most common side effects of comfrey creams used in the studies.

Severe Side Effects

Comfrey contains PAs, substances that can cause significant damage, including:

  • Liver damage
  • Sinusoidal obstruction syndrome (blockage of veins in the liver)
  • Cancer
  • Fetal harm (teratogen)
  • Death

Therefore, it should never be taken by mouth. In 2001, the FDA banned oral comfrey products.

Since these toxic substances can be absorbed through the skin, there's concern about the safety of comfrey cream applied topically. It's typically only used in small amounts for a very short period.

Experts suggest not using comfrey cream for longer than 10 days in a row. Using it no more than four to six weeks a year as a general guideline would be best.

If you're considering using the cream, consult your healthcare provider first. You and your healthcare provider should weigh the pros and cons and use it only under their supervision.


To reduce the risk of side effects, never apply comfrey cream to broken skin or open wounds as it may be more highly absorbed by the body.

Don't use comfrey products if you have or are at risk of having liver disease, cancer, or are taking any medication that affects the liver since it may increase the risk of liver toxicity.

Comfrey is not recommended for children under 3 years old, as it's not been studied in that population.

Comfrey shouldn't be used in any form during pregnancy or nursing due to the risk of liver damage to infants.


Comfrey contains toxic substances that cause liver damage, cancer, and death. It should never be taken by mouth. It should only be used in small amounts for short periods as a cream. Consult your healthcare provider before using.

Comfrey ointment
Verywell / Anastasia Tretiak

Dosage: How Much Comfrey Cream Should I Use? 

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.

There is no daily recommended allowance for comfrey, sold in creams, ointments, gels, and salves. The following applications have been used in research:

  • Back pain: An ointment containing 35% comfrey root extract, with or without 1.2% methyl nicotinate, applied three times a day for five days
  • Osteoarthritis: A specific ointment containing 35% comfrey root extract, with or without tannic acid, aloe vera gel, eucalyptus oil, and frankincense oil; applied to the knee three times a day for three to six weeks
  • For sprains: An ointment containing 35% comfrey extract; applied to ankle sprains four times daily for eight days

What Happens If I Use Too Much Comfrey Cream?

Using large amounts of comfrey cream or using it for extended periods of time increases the risk of side effects like liver toxicity.


Because of the risk of liver toxicity, comfrey cream shouldn't be used with other medicines that may also cause liver damage.

The most common over-the-counter medication that can be toxic to the liver is Tylenol (acetaminophen). Other prescription medicines that may harm the liver include:

  • Birth control pills
  • Antibiotics like erythromycin, tetracycline, or amoxicillin-clavulanate
  • Some anti-seizure medicines
  • Methotrexate
  • Cholesterol-lowering medicines like statins

Some supplements may also harm the liver, including:

It is essential to carefully read a supplement's ingredients list and nutrition facts panel to learn which ingredients are in the product and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

How to Store Comfrey Cream

Store comfrey cream according to package instructions, typically at room temperature (between 68 and 77 degrees F) and out of reach of children and pets. Discard after a year or according to labeling.

Similar Supplements

Other herbal supplements that may have benefits for back pain include:

  • Cayenne
  • Devil's claw
  • White willow bark
  • Lavender
  • Magnesium
  • Calcium/Vitamin D

Some other supplements that may be useful for osteoarthritis are:

Frequently Asked Questions

  • What alternatives to comfrey cream are there for back pain?

    Back pain is often treated with medication such as over-the-counter pain relievers.

    Other alternative therapies may help to ease the pain. Undergoing massage or taking up yoga may help alleviate pain and help people with back or joint problems function more easily.

    Acupuncture has also shown solid evidence of benefit for back pain.

    And topical capsaicin cream may help to relieve pain temporarily.

  • Which part of the comfrey plant has the lowest level of pyrrolizidine alkaloids (PAs)?

    The plant leaves have a lower concentration of PAs than the roots. For this reason, some topical products are advertised as made from comfrey leaves, but it's safest to choose a PA-free product.

  • Can comfrey be used for cracked nipples during breastfeeding?

    Although topical comfrey has been used for this indication, there's little evidence that it helps and can pose a big risk for nursing babies. If your healthcare provider recommends it, make sure to use it on intact skin for a small amount of time, and be careful that infants do not ingest it.

Sources of Comfrey & What to Look For 

Comfrey may be used topically as a cream, ointment, salve, or paste. Avoid taking comfrey orally (by mouth).

Food Sources of Comfrey

Some people ingest comfrey roots or leaves or use them in teas. This is not recommended due to the presence of chemicals that can cause organ damage and cancer.

Comfrey Supplements

For topical comfrey cream, look for products labeled as free of pyrrolizidine alkaloids. These have a lower risk of serious side effects like liver damage.

When selecting a brand of supplements, look for products certified by ConsumerLab, USP, or NSF. These third-party organizations test products to ensure they were manufactured safely and contain the ingredients indicated on the labeling without contaminants.


Comfrey cream, a topical herbal product, is thought to reduce inflammation and pain when applied to the skin. Researchers have found it does seem to reduce pain in some conditions, including back pain, osteoarthritis, and ankle sprains.

However, comfrey can also contain toxic substances called pyrrolizidine alkaloids that cause liver damage, cancer, and death. You should never ingest comfrey by mouth. Consult your healthcare provider before using comfrey cream.

24 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Salehi B, Sharopov F, Boyunegmez Tumer T, et al. Symphytum species: A comprehensive review on chemical composition, food applications and phytopharmacology. Molecules. 2019;24(12):2272. doi:10.3390/molecules24122272

  2. Avila C, Breakspear I, Hawrelak J, Salmond S, Evans S. A systematic review and quality assessment of case reports of adverse events for borage (Borago officinalis), coltsfoot (Tussilago farfara) and comfrey (Symphytum officinale)Fitoterapia. 2020;142:104519. doi:10.1016/j.fitote.2020.104519

  3. National Library of Medicine, National Institutes of Health. Comfrey.

  4. Drugs and Lactation Database, National Library of Medicine. Comfrey.

  5. Royal Pharmaceutical Society. Comfrey: Ancient and Modern Uses.

  6. Giannetti BM, Staiger C, Bulitta M, Predel HG. Efficacy and safety of comfrey root extract ointment in the treatment of acute upper or lower back pain: results of a double-blind, randomised, placebo-controlled, multicentre trial. Br J Sports Med. 2010;44(9):637-41. doi:10.1136/bjsm.2009.058677

  7. Cameron M, Chrubasik S. Topical herbal therapies for treating osteoarthritis. Cochrane Database Syst Rev. 2013;5(5):CD010538. doi:10.1002/14651858.CD010538

  8. Smith DB, Jacobson BH. Effect of a blend of comfrey root extract (Symphytum officinale L.) and tannic acid creams in the treatment of osteoarthritis of the knee: randomized, placebo-controlled, double-blind, multiclinical trials. J Chiropr Med. 2011;10(3):147-56. doi:10.1016/j.jcm.2011.01.003

  9. Laslett LL, Quinn SJ, Darian-Smith E, et al. Treatment with 4Jointz reduces knee pain over 12 weeks of treatment in patients with clinical knee osteoarthritis: a randomised controlled trial. Osteoarthritis Cartilage. 2012;20(11):1209-16. doi:10.1016/j.joca.2012.07.019

  10. Adeneye AA. Subchronic and chronic toxicities of african medicinal plants. In: Toxicological Survey of African Medicinal Plants. Elsevier; 2014:99-133. doi:10.1016/B978-0-12-800018-2.00006-6

  11. Staiger, C. Comfrey root: from tradition to modern clinical trials. Wien Med Wochenschr. 2013;163:58–64. doi:10.1007/s10354-012-0162-4

  12. Mei N, Chen T, Ning B, Guo L. Transcriptomic profiling for safety and toxicity evaluation of nutraceuticals. In: Nutraceuticals. Elsevier; 2021:299-313. doi:10.1016/B978-0-12-821038-3.00022-7

  13. Frost R, MacPherson H, O'Meara S. A critical scoping review of external uses of comfrey (Symphytum spp.)Complement Ther Med. 2013;21(6):724-745. doi:10.1016/j.ctim.2013.09.009

  14. Moreira R, Pereira DM, Valentão P, Andrade PB. Pyrrolizidine Alkaloids: Chemistry, Pharmacology, Toxicology and Food SafetyInt J Mol Sci. 2018;19(6):1668. doi:10.3390/ijms19061668

  15. National Library of Medicine, National Institutes of Health. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury.

  16. Kucera A, Barna M, Holcova S, Horacek O, Hladiková M, Ottillinger B. Tolerability and effectiveness of an antitrauma cream with comfrey herb extract in pediatric use with application on intact and on broken skinInt J Pediatr Adolesc Med. 2018;5(4):135-141. doi:10.1016/j.ijpam.2018.11.002

  17. Medline Plus, National Library of Medicine. Drug-induced liver injury.

  18. Navarro VJ, Khan I, Björnsson E, Seeff LB, Serrano J, Hoofnagle JH. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363-373. doi:10.1002/hep.28813

  19. National Center for Complementary and Integrative Health. Complementary Health Approaches for Chronic Pain: What the Science Says.

  20. Vickers AJ, Vertosick EA, Lewith G, et al. Acupuncture for Chronic Pain: Update of an Individual Patient Data Meta-Analysis. J Pain. 2018;19(5):455-474. doi:10.1016/j.jpain.2017.11.005

  21. Gagnier JJ, Oltean H, van Tulder MW, Berman BM, Bombardier C, Robbins CB. Herbal medicine for low back pain: A Cochrane reviewSpine (Phila Pa 1976). 2016 Jan;41(2):116-33. doi:10.1097/01.brs.0000249525.70011.fe

  22. Staiger C. Comfrey root: from tradition to modern clinical trialsWien Med Wochenschr. 2013;163(3-4):58-64. doi:10.1007/s10354-012-0162-4

  23. National Library of Medicine, National Institutes of Health. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury.

  24. NIH Office of Dietary Supplements. Dietary Supplements: What You Need to Know.

By Megan Nunn, PharmD
Megan Nunn, PharmD, is a community pharmacist in Tennessee with over twelve years of experience in medication counseling and immunization.