comfrey root extract

Comfrey root extract is a topical herbal preparation obtained from the roots of Symphytum officinale, traditionally used for pain, inflammation, and swelling of muscles and joints, minor sprains, bruises, and osteoarthritis. Modern randomized controlled trials and regulatory assessments (e.g., EMA/HMPC) support short-term use of standardized, pyrrolizidine-alkaloid–reduced comfrey root extracts on intact skin for relief of symptoms in minor sprains, contusions, strains, acute back myalgia, ankle sprains, and painful osteoarthritis of the knee, with efficacy comparable or superior to topical diclofenac in some studies.[3][5][7] Pharmacologically, comfrey root extract appears to exert local analgesic and anti-inflammatory effects via constituents such as allantoin, rosmarinic acid, caffeic acid derivatives, tannins, and glycopeptides that promote tissue regeneration, modulate prostaglandin and eicosanoid synthesis, and show anticomplementary and anti-inflammatory activity in preclinical models.[2][3] However, comfrey root also contains unsaturated pyrrolizidine alkaloids, which are hepatotoxic, mutagenic, and carcinogenic when absorbed systemically; oral products have caused hepatic veno-occlusive disease and liver failure, leading authorities such as the FDA and EMA to prohibit or strongly discourage internal use and to limit pyrrolizidine alkaloid exposure from topical preparations.[1][2][5][8][13]

Brand names

Kytta-Salbe fKytta

Other names

comfrey rootSymphyti radixSymphytum officinale root extractcomfrey root fluid extractcomfrey root dry extract