Comfrey for strains, sprains and broken bones

Used with care, comfrey can reduce the healing time of minor injuries, say Sarah Stacey and Dr Sarah Brewer

For thousands of years, herbalists have used the perennial herb comfrey (Symphytum officinale) with its thick grey-green leaves and bell-like white pink and mauve flowers to help heal bruises, sprains, fractures and broken bones. It?s common name is `knitbone? and a comfrey compress, applied immediately to a sprained ankle, can significantly speed healing after an injury. Its main active component is a substance called allantoin, which boosts the production of new cells.

This evergreen European native, which likes moist marshy places and now grows in all temperate areas of the world, is also good for healing wounds. In 1734, K’Eogh in his Irish herbal wrote that it ‘heals all inward wounds and ruptures’. Comfrey oil or ointment is used to treat acne and boils, and to relieve psoriasis and soften scars.

Toxic warning

This herb is highly regarded for its healing properties but users should note that there have been formal warnings from both British and American regulatory bodies to manufacturers about the toxicity of compounds called pyrrolizidine alkaloids in the comfrey root if taken internally. These substances can damage the liver, affect the circulation and have also been linked with an increased risk of cancer in rats.

The experience of most herbalists is that a tincture of infusion of comfrey leaves is safe and beneficial for conditions such as stomach ulcers when prescribed by a qualified professional and used for limited periods of time (a maximum of six weeks is advisable). Applying comfrey externally in the form of oil, tincture, ointment, cream or a poultice of chopped leaves has not provoked such warnings.