Comfrey Salve: How to Make It and When It Is Used

Comfrey salve is an infused oil of Comfrey, Symphytum officinale, root or leaf, set with beeswax at roughly one part wax to five parts oil by weight. It is applied to sprains, strains, bruises, closed fractures, sore joints, and dry cracked skin, and it is not applied to broken skin or an open wound, not used for more than four to six weeks in a year, and not used in pregnancy or lactation, because the plant's pyrrolizidine alkaloids injure the liver and are absorbed through a wound. Comfrey is never taken internally in current Western practice. Those are the conditions the German Commission E sets for the plant, and they are how the tradition now uses the herb Dioscorides and Culpeper knew as knitbone.

The plant

Comfrey is a coarse hairy perennial of damp ground, with a black-skinned, white-fleshed root and large rough leaves, flowering purple or cream in early summer. The root is dug in autumn or early spring and the leaf cut before flowering. It is cool and moist, and its actions are vulnerary, demulcent, astringent, and cell proliferant, which the tradition attributes to allantoin, a constituent that hastens the closing of tissue, together with the mucilage and tannin. Culpeper places it under Saturn and gives it for broken bones, the classical use in the name Symphytum, from the Greek for growing together. Gerard, Parkinson, and the Eclectics all gave it internally for ulcers and bleeding, and that use is the one that has been revised.

Russian Comfrey, Symphytum × uplandicum, the hybrid grown for compost and fodder, and Prickly Comfrey, Symphytum asperum, are higher in the alkaloid echimidine and are not used for medicine. The root carries more of the alkaloids than the leaf, and the young leaf more than the old.

The modern rule

The pyrrolizidine alkaloids of comfrey, symphytine and its relatives, cause veno-occlusive disease of the liver, a closing of the small hepatic veins, when taken over time, and the case reports of the 1980s and 1990s ended the internal use. The regulators followed: Germany's Commission E limits comfrey to external use on unbroken skin, sets a maximum of 100 micrograms of pyrrolizidine alkaloids in a day's application, and restricts use to four to six weeks a year; the United Kingdom and Canada removed the oral products; and the United States Food and Drug Administration advised the removal of comfrey from oral supplements in 2001. The manufactured creams in Europe are now made from a root extract with the alkaloids removed. The herbal tradition holds to the same rule, and the salve is its form of the plant.

Making the infused oil

1. Use dried root, cut, or dried leaf, crumbled; the fresh plant holds too much water and moulds the oil. Dried root gives the stronger salve; leaf the milder.
2. Weigh the herb and cover it with five to eight times its weight of olive oil, in a jar for the solar method or a double boiler for the heat method. Fifty grams of root to 300 millilitres of oil is a working batch.
3. Solar method: cap the jar, stand it in a sunny window for two to four weeks, shake it daily, and strain. Heat method: hold the oil and herb at a low warmth, below the temperature at which the oil sizzles, for two to four hours, then strain. The heat method suits root.
4. Strain through muslin, press, and let the oil stand a day so any water settles, then pour it off the sediment.

Calendula, Calendula officinalis, and Plantain, Plantago major, are the usual companions in the oil, and both may go on broken skin where comfrey may not; a wound salve is made of those two without comfrey.

Setting the salve

Melt 30 grams of beeswax into 150 millilitres of the infused oil in a double boiler, stir, and test a drop on a cold spoon; more wax makes a firmer salve, more oil a softer one. A few drops of Lavender oil, Lavandula angustifolia, may be added off the heat. Pour into tins or jars and let set uncovered. A salve made with dry herb and clean oil keeps a year in a cool place.

Use

The salve is rubbed into the skin over a sprain, a bruise, a closed fracture, a sore back, or a swollen joint, two or three times a day, for a course of no more than four to six weeks. The old caution of the herbals, that comfrey closes a wound so fast it seals infection in, still stands beside the modern one, and the two agree that the salve belongs on skin that is whole. A poultice of the fresh leaf on a sprain is the same medicine used in the field. Chinese medicine has no comfrey, but its trauma liniments serve the same tissue in the same way.

Not medical advice.