Comfrey - Symphytum officinale L.

Date: February 18, 2014 Posted by: Dafydd Monks

Common Names

Comfrey, Knitbone, Boneset, Knitback, Consound, Blackwort, Bruisewort, Slippery Root, Gum Plant, Ass Ear. Llysiau'r cwlwm (Welsh) Reinweld (German), Grande consoude (French).


Symphytum officinale illustration A strongly robust branching perennial with many long (~25 cm) tongue shaped leaves emerging from a substantial fleshy rootstock, comfrey grows up to 120cm in height. It is a hairy plant: the leaves, and especially the stems are roughly hairy; these hairs may be irritant. The leaves are decurrently ‘winged’, blending into the stem; these wings are visible as far down the stem as the next leaf junction. This winging can clearly be seen in the illustration above. The leaves decrease in size the further up the stem they grow, and the stems terminate in one-sided clusters of drooping flowers, either creamy white to yellow, or purple, growing on short stalks. The flowers have long pointed calyx teeth, and have bell-shaped corollas. Symphytum officinale is frequently found in damp places such as ditches and riverbanks, and is common in England, Wales and Lowland Scotland, but is rare in the highlands of Scotland and almost absent from Ireland.

Parts Used

Foliage; traditionally also the Rhizome.

Collection and Processing

Foliage: Mature leaves should be collected throughout the summer, avoiding the early leaves which are high in Pyrrolizidine Alkaloids
Rhizomes: The rhizomes and roots should be unearthed and dried in the autumn after the plant has died down. It is at this point that the Allantoin and Inulin levels are highest.


Foliage: Mucilage, tannin, allantoin, Pyrrolizidine Alkaloide including symphytine, echinidine. Vitamin B12
Rhizomes: around 29% mucilage (polysaccharides of fructose and glucose), phytosterols, triterpenoid (isobauerenol), phenolic compounds (including caffeic, chlorogenic and lithospermic acids), tannin, asparagine, pyrrolizidine alkaloids (including symphytine, cynoglossine, consolidine), inulin, silicic acid.


Foliage: Demulcent, anti-inflammatory, vulnerary, antirheumatic, antihaemorrhagic.
Rhizomes: Demulcent, vulnerary, antihaemorrhagic, cell-proliferant, astringent, expectorant.


Foliage: Topically; applied, and most known as an ointment or poultice for sprains, strains and bruising. Internally; Arthritis, Rheumatic Pain, Gastric Ulcers
Rhizomes: Topically; applied and most known as an ointment for sprains, fractures, strains, herniae and ulceration.


Symphytum is well known for its impressive tissue-healing actions: it is a wound healer, specifically effective in encouraging wounds and ulcers which will not ‘knit’ back together to form granulation tissue and close. This action has a down-side however; care must be taken to ensure that infected wounds do not ‘scab over’ before the infection has been removed. Failure to do this can result in the formation of abscesses. Another area in which Symphytum demonstrates a considerable action to improve tissue integrity is in broken bones, sprained ligaments and arthritis: Symphytum has been shown to increase the density of remodelled bone, and to improve the osseointegration of metal implants into bone tissue, even when low doses are administered. These attributes have been linked to the presence of Allantoin which is a cell proliferating agent.

The tissue healing actions of Allantoin lead to Symphytum (both foliage and rhizomes) being used to treat gastric ulcers of the stomach and duodenum, however internal use is questioned by the presence of Pyrrolizidine Alkaloids which are stated to be hepatotoxic.



GSL Schedule 1 (Unrestricted).
Fluid Extract: 1:1, 25% alcohol. 2 - 8ml daily.


GSL Schedule 2 (External Use Only)

2 – 4 g by decoction

Fluid Extract: 1:1, 25% alcohol. 2- 4 ml daily.

Ointment: 5 – 20% Dried Herb or dried root by weight. Commission E suggest that daily applied dosage should not exceed 100 mcg of pyrrolizidine alkaloids with a 1,2-unsaturated necine structure (including N-oxides). 

Further Reading 

Barker, J., 2001. The Medicinal Flora of Britain and Northwestern Europe, Winter Press.
Bartram, T., 1998. Bartram’s Encyclopedia of Herbal Medicine New Ed., London: Robinson Publishing.
British Herbal Medicine Association, 1996. British Herbal Pharmacopoeia, Exeter: British Herbal Medicine Association.
Grieve, M., 1992. A Modern Herbal the Medicinal, Culinary, Cosmetic and Economic Properties, Cultivationand Folklore of Herbs, Grasses, Fungi, Shrubs and Trees with All Their Modern Scientific Uses, London: Tiger Books International.
Hills, L.D., 1976. Comfrey: past, present, and future, London: Faber And Faber.
Hoffmann, D., 2003. Medical Herbalism: The science and practice of herbal medicine, Rochester, Vermont: Healing Arts Press.
Holmes, P., 2007. The Energetics of Western Herbs a Materia Medica Integrating Western and Chinese Herbal Therapeutics Rev. & enl. 4th ed., Cotati, CA: Snow Lotus Press.
Menzies-Trull, C., 2003. Herbal Medicine Keys to Physiomedicalism Including Pharmacopoeia, Newcastle, Staffs: Faculty of Physiomedical Herbal Medicine.
Newall, C.A., Anderson, L.A. & Phillipson, J.D., 1996. Herbal Medicines: A Guide for Healthcare Professionals, London: Pharmaceutical Press.
Spin-Neto, R. et al., 2010. Original paper: Homeopathic Symphytum officinale increases removal torque and radiographic bone density around titanium implants in rats. Homeopathy, 99, pp.249–254.