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Dietary supplement

Comfrey Ingredients & Drug Interactions

by Hawaii Pharm

Comfrey label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Comfrey against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Comfrey is a dietary supplement by Hawaii Pharm with 1 active ingredient. Its ingredients are commonly taken for bruises and sprains, muscle and joint pain, minor wounds and skin irritation.Based on those ingredients, 438 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Comfrey Leaf Extract, Dry. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Comfrey by Hawaii Pharm

Ask about any prescription or over-the-counter medication and we check it for interactions with Comfrey by Hawaii Pharm — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Comfrey by Hawaii Pharm

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 16, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: Comfrey Leaf Extract in dry form. Comfrey has been used traditionally for respiratory conditions, pain, and other purposes, though reliable evidence for most of these uses is lacking.

The liquid also contains alcohol, water, and glycerin as inactive ingredients to deliver the herb.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Comfrey product and its label doesn't state a use — see Comfrey's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold doesn't establish that comfrey relieves bronchitis, angina, back pain, cough, or cancer. All the conditions listed in the data are marked as having insufficient reliable evidence to rate comfrey's effectiveness.

If you're considering this product for one of these purposes, talk with your doctor about whether the evidence supports its use for your situation.

The evidence, ingredient by ingredient Comfrey

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Oral comfrey — like this liquid — is considered unsafe because of liver toxicity. The herb contains pyrrolizidine alkaloids that can cause serious liver damage, including cirrhosis, fibrosis, and hepatic failure.

Symptoms can range from sudden abdominal pain and vomiting to gradual swelling and progressive weakness, and liver failure can develop even months or years after use stops. Topical use on unbroken skin for short periods may be more acceptable, but this is an oral product.

Do not use comfrey during pregnancy — it poses liver toxicity and possible harm to the baby. Do not use while breastfeeding because harmful compounds pass into breast milk.

When applied to skin, comfrey is generally well tolerated, though some users report eczema, rash, itching, or irritation at the application site.

Side effects, ingredient by ingredient Comfrey

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Comfrey.
  • The most serious interaction on file is rated Moderate.
  • For scale: 439 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check with your doctor or pharmacist if you take any medication that can damage your liver (hepatotoxic drugs) or that speeds up how your body breaks down drugs (CYP3A4 inducers, such as phenobarbital). These are Moderate-severity interactions, and the risk of liver harm increases when comfrey is combined with them.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Oral comfrey carries a serious risk of liver damage that the data advises against. This product is not recommended for internal use.

If you're considering it anyway — or if you've been taking it — talk with your doctor or pharmacist before continuing, especially if you take any medication that affects your liver or how your body processes drugs. Pregnant or nursing patients should not use this product.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2023.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Comfrey, straight from the product label.

Brand Hawaii Pharm
Barcode (UPC) 840253615855
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Oct 24, 2023
DSLD ID 301489
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Comfrey by Hawaii Pharm, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
0.7 mL
Maximum serving Sizes:
1 mL
Servings per container
120
UPC/BARCODE
840253615855
IngredientAmount% DV
Comfrey Leaf Extract, Dry983 mg--

Other ingredients: Alcohol, Water, Glycerin

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Brand IP Statement(s)

Hawaii Pharm Herbal Extract Highest quality since 2008

Suggested/Recommended/Usage/Directions

Suggested use: Shake well before using. For adults add about 20-30 drops (0.7-1 mL, one full squeeze of the dropper bulb) to some juice or water, up to 4 times a day.

Precautions

Warning: We recommend to seek expert medical advice before taking.

Do not use if you are allergic to any ingredients.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

May affect the ability to drive and operate machinery. May have contraindications, can cause side effects and adverse reactions. Do not use if seal is broken or missing.

Keep out of the reach of children!

Storage

Store in a cool dry place.

Seals/Symbols

cGMP Made in compliance with cGMP 21 CFR 111 in an FDA registered and inspected facility.

Organic Alcohol Based USA Made in United States of America

FDA Disclaimer Statement

This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure or prevent any disease.

General Statements

Scan this QR-code to get 15% discount on your next purchase. Limited time deal.

Formula

Symphytum officinale

Organic Alcohol Based

Formulation

Only natural ingredients Purity is laboratory tested and verified

All the raw materials are gluten-free by their nature No artificial colors, flavors, or preservatives

Not tested on animals

Organic Alcohol Based

Made in USA, Hawaii

FDA Statement of Identity

Herbal Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Comfrey by Hawaii Pharm label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Comfrey label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Comfrey by Hawaii Pharm

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size0.7 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.

Comfrey Leaf Extract, Dry

Interacts with
438 drugs
983 mg per serving Form: Symphytum officinale Leaf Extract, Dry

Comfrey is a traditional herb used mainly on the skin for bruises, sprains, and joint pain, and some topical products show modest benefit for these us...

Comfrey Leaf Extract, Dry monograph & interactions

Other (inactive) ingredients: Alcohol, Water, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Comfrey by Hawaii Pharm Drug Interactions

Want to check YOUR meds against Comfrey?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
438Drugs
438 Moderate

Ingredients driving the most interactions

Comfrey Leaf Extract, Dry 438

Individual Drug Interactions

The ingredients in Comfrey interact with 438 drugs. Click any drug to see the details.

1 of the 1 ingredient in Comfrey interact with drugs. Each result below shows which ingredient is responsible. Comfrey Leaf Extract, Dry

Each ingredient & the kinds of drugs it affects

For each ingredient in Comfrey with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Comfrey Leaf Extract, Dry2 drug types · 438 drugs

Cytochrome P450 3A4 (Cyp3A4) Inducers

Theoretically, CYP3A4 inducers might increase the risk of adverse effects from the pyrrolizidine alkaloid constituents in comfrey.
CYP3A4 enzymes convert pyrrolizidine alkaloids, constituents of comfrey, to toxic metabolites. Some case reports show that enzyme inducers, such as phenobarbital, seem to enhance the toxicity of comfrey.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, comfrey might have additive adverse effects on the liver when used with hepatotoxic drugs.
Due to its pyrrolizidine alkaloid constituents, comfrey can cause hepatotoxic effects, including ascites, cirrhosis, hepatic fibrosis, hepatomegaly, and sinusoidal obstruction syndrome.

Likelihood Possible Evidence D
Comfrey Leaf Extract, Dry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Comfrey, from the product label.

Hawaii Pharm

See all Hawaii Pharm products
Name
Hawaii Pharm LLC
Street Address
510 Sumner St. Ste. 613
City
Honolulu
State
HI
ZipCode
96817
Phone Number
888-854-2924
Web Address
www.hawaiipharm.com
Pharmacist Counseling Corner

Comfrey by Hawaii Pharm: Common Questions

Does Comfrey by Hawaii Pharm interact with any medications?
Yes. Based on its ingredients, Comfrey has a known interaction with 438 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Comfrey contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or breastfeeding?
No. Comfrey is considered likely unsafe during pregnancy because of liver toxicity and possible harm to the baby. Do not use it while breastfeeding either — harmful compounds pass into breast milk. Talk with your doctor or pharmacist about safe alternatives.
Is comfrey safe to take by mouth?
The data advises against oral use. Comfrey contains pyrrolizidine alkaloids that can damage your liver, potentially causing serious conditions like cirrhosis, fibrosis, and hepatic failure. These problems can develop suddenly or gradually, and may appear months or even years after you stop taking it.
What liver problems can comfrey cause?
Comfrey can cause acute sinusoidal obstruction syndrome (sudden abdominal pain, vomiting, and liver enlargement), subacute disease (ascites — fluid buildup in the abdomen — along with pain and digestive symptoms), or chronic toxicity (progressive weakness and swelling). Severe cases can lead to hepatic failure.
Does comfrey work for back pain, cough, or bronchitis?
The evidence we hold doesn't establish that comfrey is effective for these conditions. The data rates all of them as having insufficient reliable evidence. If you're considering comfrey for any of these purposes, talk with your doctor about what the evidence actually supports.
What's in this liquid besides the comfrey extract?
The liquid contains alcohol, water, and glycerin — these are inactive ingredients that help deliver the herb. The active ingredient is the comfrey leaf extract itself.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Comfrey label
Go deeper

The Full Monographs Behind Comfrey’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Comfrey

Interacts with 438 drugs

Comfrey is a traditional herb used mainly on the skin for bruises, sprains, and joint pain, and some topical products show modest benefit for these uses. However, comfrey contains compounds...

Read the full Comfrey monograph →
Sources

Sources & How We Checked

Comfrey's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 13 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Comfrey 13 references
  1. Stewart MJ, Steenkamp V. Pyrrolizidine poisoning: a neglected area in human toxicology. Ther Drug Monit 2001;23:698-708. PubMed
  2. Food and Drug Administration. FDA Advises Dietary Supplement Manufacturers to Remove Comfrey Products From the Market. July 6, 2001. Available at: http://www.cfsan.fda.gov/~dms/dspltr06.html.
  3. Stickel F, Seitz HK. The efficacy and safety of comfrey. Public Health Nutr 2000;3:501-8. PubMed
  4. Chojkier M. Hepatic sinusoidal-obstruction syndrome: toxicity of pyrrolizidine alkaloids. J Hepatol 2003;39:437-46. PubMed
  5. Wang YP, Yan J, Fu PP, Chou MW. Human liver microsomal reduction of pyrrolizidine alkaloid N-oxides to form the corresponding carcinogenic parent alkaloid. Toxicol Lett 2005;155:411-20. PubMed
  6. Predel, H. G., Giannetti, B., Koll, R., Bulitta, M., and Staiger, C. Efficacy of a comfrey root extract ointment in comparison to a diclofenac gel in the treatment of ankle distortions: results of an observer-blind, randomized, multicenter study. Phytome
  7. Gyorik, S. and Stricker, H. Severe pulmonary hypertension possibly due to pyrrolizidine alkaloids in polyphytotherapy. Swiss.Med.Wkly. 4-4-2009;139(13-14):210-211.
  8. Giannetti, B. M., Staiger, C., Bulitta, M., and Predel, H. G. 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 Spor PubMed
  9. Tanret, I. and Duh, D. [Pharmaceutical sheet. Symphytum officinale L., dermal use (Flexagile cream)]. J Pharm.Belg. 2012;(1):41-42.
  10. Laslett, L. L., Quinn, S. J., Darian-Smith, E., Kwok, M., Fedorova, T., Korner, H., Steels, E., March, L., and Jones, G. Treatment with 4Jointz reduces knee pain over 12 weeks of treatment in patients with clinical knee osteoarthritis: a randomised contr
  11. Frost R, Macpherson H, O'meara S. A critical scoping review of external uses of comfrey (Symphytum spp.). Complement Ther Med. 2013;21(6):724-45. PubMed
  12. Pabst H, Schaefer A, Staiger C, Junker-samek M, Predel HG. Combination of comfrey root extract plus methyl nicotinate in patients with conditions of acute upper or low back pain: a multicentre randomised controlled trial. Phytother Res. 2013;27(6):811-7. PubMed
  13. 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) PubMed

See these in context on the Comfrey monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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