# Comfrey (Symphytum officinale)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/comfrey
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 4 / 10
**Category:** European
**Also Known As:** Symphytum officinale, Knitbone, Boneset, Bruisewort, Blackwort, Slippery Root, Healing Herb, Ass Ear

## Overview

Comfrey (Symphytum officinale) contains allantoin, a purine derivative that accelerates cell proliferation and tissue regeneration. This European herb demonstrates significant [anti-inflammatory](/ingredients/condition/inflammation) and analgesic properties through cyclooxygenase inhibition and enhanced [collagen synthesis](/ingredients/condition/skin-health).

## Health Benefits

• Reduces osteoarthritis pain by 54.7% and improves joint function by 58% (RCT, n=220)
• Alleviates acute ankle sprain pain more effectively than diclofenac (83.2% vs 72.4% reduction)
• Decreases back pain and improves mobility in acute myalgia (randomized trial)
• Promotes wound healing through allantoin-induced cell proliferation
• Reduces inflammation via rosmarinic acid's [anti-inflammatory](/ingredients/condition/inflammation) properties

## Mechanism of Action

Comfrey's primary bioactive compound allantoin promotes cell proliferation by enhancing DNA synthesis and collagen formation. Rosmarinic acid and caffeic acid derivatives inhibit cyclooxygenase-2 (COX-2) and lipoxygenase pathways, reducing [prostaglandin](/ingredients/condition/inflammation) E2 and leukotriene synthesis. The herb also contains mucilage polysaccharides that provide protective coating effects on damaged tissues.

## Clinical Summary

A randomized controlled trial (n=220) demonstrated comfrey cream reduced osteoarthritis pain by 54.7% and improved joint function by 58% versus placebo. In acute ankle sprains, comfrey showed superior pain reduction compared to diclofenac (83.2% vs 72.4%). Multiple randomized trials support its efficacy for back pain and wound healing, though most studies used topical preparations. Evidence quality is moderate with consistent positive outcomes across musculoskeletal conditions.

## Nutritional Profile

Comfrey leaf and root contain a complex array of bioactive compounds rather than serving as a conventional nutritional source. **Key bioactive compounds:** Allantoin (0.6–4.7% in root, 0.3–0.5% in leaf) is the primary wound-healing agent, promoting cell proliferation and tissue regeneration. Rosmarinic acid (up to 0.2% in leaf extracts) provides [anti-inflammatory](/ingredients/condition/inflammation) and [antioxidant activity](/ingredients/condition/antioxidant). Mucilage polysaccharides (up to 29% in root) contribute demulcent and soothing properties. **Pyrrolizidine alkaloids (PAs):** Symphytine, lycopsamine, intermedine, and echimidine are present at approximately 0.02–0.18% in root and lower levels in leaf (~0.003–0.02%); these are hepatotoxic and restrict internal use. **Tannins:** Condensed and hydrolyzable tannins (3–8%) contribute astringent and [antimicrobial](/ingredients/condition/immune-support) effects. **Phenolic acids:** Caffeic acid, chlorogenic acid, and lithospermic acid contribute to antioxidant capacity. **Triterpene saponins:** Including isobauerenol and β-sitosterol (trace to 0.5%) support anti-inflammatory activity. **Amino acids & protein:** Leaves contain approximately 15–20% crude protein (dry weight basis), including asparagine. **Minerals:** Notable levels of potassium (~2.5–3.5% dry weight), calcium (~1.0–1.5%), phosphorus (~0.3–0.6%), iron (~100–300 ppm), manganese, and zinc. **Vitamins:** Modest amounts of vitamin C (~30–60 mg/100 g fresh leaf), provitamin A (β-carotene), and B-vitamins (B1, B2, B12 — comfrey is one of the few land plants reported to contain trace vitamin B12, though bioavailability is debated and amounts are nutritionally insignificant at ~0.3–0.5 µg/100 g dry weight). **Fiber:** Leaves contain ~10–15% crude fiber (dry weight). **Fatty acids:** Gamma-linolenic acid (GLA) detected in trace amounts in seed oil. **Bioavailability notes:** Allantoin is readily absorbed topically and is the basis for comfrey's external therapeutic use; rosmarinic acid has moderate oral bioavailability but is primarily utilized in topical formulations for comfrey due to PA toxicity concerns. Topical preparations are standardized to contain allantoin (typically ≥0.4%) and are processed to reduce PA content to below detectable limits (<0.35 µg/g or PA-free) for safe clinical use. Internal consumption is contraindicated due to cumulative PA hepatotoxicity and veno-occlusive disease risk.

## Dosage & Preparation

Clinically studied dose: 10% comfrey root extract ointment (from 60% ethanolic extract) applied topically 3 times daily for 1-3 weeks. For external use only - internal consumption is prohibited due to hepatotoxic pyrrolizidine alkaloids. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Oral comfrey contains pyrrolizidine alkaloids that can cause hepatotoxicity and should be avoided internally. Topical preparations using alkaloid-free extracts are generally safe but may cause contact dermatitis in sensitive individuals. Comfrey should not be used during pregnancy or breastfeeding due to potential teratogenic effects. No significant drug interactions reported with topical use, but avoid on broken skin due to systemic absorption risk.

## Scientific Research

Multiple randomized controlled trials support topical comfrey root extract for musculoskeletal conditions, including a double-blind, placebo-controlled RCT (n=220) showing significant pain and function improvements in knee osteoarthritis. Comparative trials demonstrated superiority to diclofenac for ankle sprains, though specific PMIDs were not provided in the research dossier.

## Historical & Cultural Context

Comfrey has been used in Greek, Roman, and European folk medicine since approximately 400 BC for wound healing, bleeding control, and treating bruises and sprains. Traditional internal uses for gastrointestinal issues have been discontinued due to safety concerns, with modern use limited to external applications.

## Synergistic Combinations

Arnica montana, MSM, Boswellia serrata, Turmeric, Glucosamine

## Known Interactions

| Substance | Severity | Summary | URL |
|---|---|---|---|
| Marshmallow Root | SAFE | 🟢 SAFE — Comfrey and Marshmallow Root can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/marshmallow-root |
| Slippery Elm | SAFE | 🟢 SAFE — Comfrey and Slippery Elm can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/slippery-elm |
| Isotretinoin | SAFE | 🟢 SAFE — Comfrey and Isotretinoin can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/isotretinoin |
| Dapsone | SAFE | 🟢 SAFE — Comfrey and Dapsone can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/dapsone |
| Azathioprine | SAFE | 🟢 SAFE — Comfrey and Azathioprine can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/azathioprine |
| Mycophenolate | SAFE | 🟢 SAFE — Comfrey and Mycophenolate can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/mycophenolate |
| Cyclosporine | SAFE | 🟢 SAFE — Comfrey and Cyclosporine can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/cyclosporine |
| Febuxostat | SAFE | 🟢 SAFE — Comfrey and Febuxostat can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/febuxostat |
| Penicillamine | SAFE | 🟢 SAFE — Comfrey and Penicillamine can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/penicillamine |
| Turmeric Latte | SAFE | 🟢 SAFE — Comfrey and Turmeric Latte can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/turmeric-latte |
| Matcha | SAFE | 🟢 SAFE — Comfrey and Matcha can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/matcha |
| Kombucha | SAFE | 🟢 SAFE — Comfrey and Kombucha can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/kombucha |
| Energy Drinks | SAFE | 🟢 SAFE — Comfrey and Energy Drinks can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/energy-drinks |
| Nicotine | SAFE | 🟢 SAFE — Comfrey and Nicotine can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/nicotine |
| Vitamin E | SAFE | 🟢 SAFE — Comfrey and Vitamin E can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/vitamin-e |
| Vitamin B1 | SAFE | 🟢 SAFE — Comfrey and Vitamin B1 can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/vitamin-b1 |
| Vitamin B2 | SAFE | 🟢 SAFE — Comfrey and Vitamin B2 can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/vitamin-b2 |
| Vitamin B3 | SAFE | 🟢 SAFE — Comfrey and Vitamin B3 can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/vitamin-b3 |
| Vitamin B5 | SAFE | 🟢 SAFE — Comfrey and Vitamin B5 can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/vitamin-b5 |
| Inositol | SAFE | 🟢 SAFE — Comfrey and Inositol can be taken together safely. | https://ingredients.hermeticasuperfoods.com/interactions/inositol |

## Frequently Asked Questions

### How much comfrey should I apply topically for joint pain?

Clinical studies used comfrey cream containing 10% comfrey extract applied 3-4 times daily. Apply a thin layer (2-4 grams) to affected area and massage gently. Treatment duration should not exceed 10 consecutive days without medical supervision.

### Is comfrey safe to take orally as a supplement?

Oral comfrey consumption is not recommended due to pyrrolizidine alkaloids that can cause liver damage and cancer. Many countries have banned internal comfrey use. Only topical preparations using alkaloid-free extracts should be considered.

### How quickly does comfrey work for pain relief?

Comfrey typically provides pain relief within 1-3 days of topical application. In clinical trials, significant improvement in osteoarthritis pain occurred within one week. Maximum benefits for acute injuries like sprains appear within 7-14 days of consistent use.

### Can comfrey interact with blood thinning medications?

Topical comfrey has no documented interactions with anticoagulant medications like warfarin or aspirin. However, avoid applying to open wounds as systemic absorption may occur. Consult healthcare providers before use if taking multiple medications.

### What's the difference between comfrey and symphytum in homeopathy?

Symphytum is the homeopathic preparation of comfrey, highly diluted according to homeopathic principles. Regular comfrey extracts contain measurable active compounds like allantoin, while homeopathic symphytum contains negligible molecular amounts. Clinical evidence supports herbal comfrey, not homeopathic preparations.

### Is comfrey safe during pregnancy and breastfeeding?

Comfrey is not recommended during pregnancy or breastfeeding due to the presence of pyrrolizidine alkaloids (PAs), which may pose hepatotoxic risks to the developing fetus and nursing infant. Most health authorities advise pregnant and breastfeeding women to avoid oral comfrey supplements entirely, though topical use on intact skin for short periods is considered lower-risk. Always consult a healthcare provider before using comfrey in any form during these periods.

### Which form of comfrey is most effective—topical cream, gel, or herbal tea?

Topical forms (creams and gels) are the most effective and safest way to use comfrey, with clinical evidence showing significant benefits for joint pain, sprains, and muscle strain through direct application. Topical delivery allows the active compounds (allantoin and rosmarinic acid) to penetrate affected tissues while minimizing systemic exposure to pyrrolizidine alkaloids. Oral forms like herbal teas carry higher hepatotoxicity risks and are not recommended; topical application is the evidence-backed standard.

### Who should avoid comfrey supplements, and are there specific health conditions that make it unsafe?

People with liver disease, hepatitis, cirrhosis, or a history of liver damage should strictly avoid comfrey due to PA-induced hepatotoxicity risk. Additionally, those taking hepatotoxic medications, pregnant or breastfeeding women, and children under 12 are advised against comfrey use. Topical application on broken skin or open wounds should also be avoided, as increased absorption of alkaloids may occur.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
*License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*