Botanical Index No. 288

Comfrey

symphytum officinale

Medicinal Actions

Alterative, Analgesic, Antiaging, Antihemorrhagic, Antiinflammatory, Antileukocyte, Antimitotic, Antimutagenic, Antipsoriatic, Antitumor, Astringent, Carcinogenic, Expectorant, Hepatotoxic, Hypotensive, Tonic, Uterotonic

Primary Conditions Treated

Cancer bone lung Candida Catarrh Chafing Cholecystosis Colitis Congestion Constipation Contusion Cough Debility Decubitis Dermatosis Diabetes Diarrhea Duodenal Ulcer Dysentery Dysmenorrhea Dyspepsia Eczema Enterosis Epicondylosis Fracture Gallstone Gastrosis Gastric Ulcer Gingivosis Gonorrhea Gout Heartburn Hematemesis Hematochezia Hemoptysis Hemorrhoid Hepatosis Hernia High Blood Pressure Hoarseness Hysteria Indolent Ulcer Inflammation Itch Leukorrhea Mastosis Metrorrhagia Myosis Nephrosis Ophthalmia Osteosis Pain Pertussis Pharyngosis Phthisis Pleurosis Psoriasis Pulmonosis Rash Respirosis Rheumatism Scrofula Sore Throat Sprain Stomatosis Strain Sunburn Swelling Tendovaginosis Tonsilosis Tuberculosis Tumor Ulcer Ulcus cruris Vaginosis Varicosis VD Wound Yeast Callus-Promoter Demulcent Emollient Hemostat Vulnerary Adenopathy Amenorrhea Anemia Angina Arthrosis Asthma Backache Bleeding Bronchosis Bruise Bug Bite

General Dosage

Do not use; do not use root; 2–4 g root as tea 3 ×/day; 2 tsp root in hot tea; 2–4 ml liquid root extract; 2–4 ml liquid extract 3 ×/day; 2–8 ml liquid leaf extract 3 ×/day; 2–8 g leaf in tea 3 ×/day; 0.25–0.5 cup fresh leaf; 6–12 g dry leaf; 9 g dry leaf:45 ml alcohol/45 ml water; 1–3 cups tea/day remembering PAs.

Safety & Contraindications

Class 2a, 2b, 2c, 2d. Long-term use discouraged. Commission E reports the herb, leaf, and root permitted for external use only. Skin should be intact and pregnant users should first consult physician. External dosage of pyrrolizidine alkaloids maximum 100 g/day for a maximum 4–6 weeks/year. Comfrey root may cause liver damage if taken internally. Contains PAs. Internal use may cause severe hepatic damage. PAs are toxic to humans, with liver damage with cirrhosis and ascites, or seneciosis, or veno-occlusive disease reported in almost all cases of severe or fatal intoxications, from intakes of 0.5 mg/kg to 3.3 mg/kg. Chronic comfrey use implicated in at least one instance of hepatic VOD. Effective July 1996, the AHP Board of Trustees recommends that all products with botanical ingredient that contain toxic PAs, including Borago officinalis, display the following cautionary statement on the label, “For external use only. Do not apply to broken or abraded skin. Do not use when nursing”. CAN cautions the PAs are genotoxic, carcinogenic, and hepatotoxic. Because of the PAs, its use in pregnancy and lactation is to be avoided. Animal studies document placental transfer and secretion into breast milk of unsaturated PAs. May speed up metabolism of other drugs. Internal use for more than 4–6 weeks is discouraged. Canadians do not allow in food. “No human being or animal should eat, drink, or take comfrey in any form”. According to studies reported in the Lawrence Review of Natural Products, rats fed comfrey roots or leaves for 600 days developed hepatocellular adenomas, with signs of liver toxicity developing within 180 days. Urinary bladder tumors developed also, even in those on the lowest levels of comfrey. The incidence of liver tumors was higher with dietary roots than with dietary comfrey leaves. Alkaloids of Russian comfrey caused chronic liver damage and pancreatic islet cell tumors after 2 years administration in animal models.

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