Comfrey is a plant native to some regions in Asia and many areas of Europe. It commonly grows as a weed in northern latitudes with temperate climates. Comfrey herb has a reputation for its effectiveness in healing wounds mainly due to the presence of allantoin, a chemical compound that is a product of uric acid oxidation.

Allantoin is a chemical that boosts cell growth and speeds up repair after tissue damage. This allows it to help with healing wounds both internally and externally. It offers protection against abnormal development of scar tissue. Users are cautioned when using this comfrey as a topical agent on deep wounds. In some cases, it can stimulate tissue formation too quickly before the wound has had time to heal in areas below the skin's surface. This can trap an infection inside and lead to the formation of abscesses.

Comfrey contains many other compounds, including steroidal saponins, pyrrolizidine, inulin, proteins, alkaloids, tannins, and mucilage. Historically, herbalists have relied on this herb to treat a wide variety of health problems. These include arthritis, varicose ulcers, acne, and burns. The effects may be enhanced when combined with calendula, which has its own reputation for having the ability to stop bleeding, fight against infection, and accelerate healing.

In children, it was traditionally used to help grow strong teeth and bones. Its common name of knitbone speaks directly to its reputation for helping repair broken bones, even old breaks that are taking a long time to heal. When added to a poultice it can help heal pulled tendons, bruised joints, and muscle damage.

The herb is a demulcent meaning it contains a specific polysaccharide called mucilage. Mucilage cools, moistens, reduces inflammation, and may stimulate local immune responses. This makes it helpful for treating hiatal hernias, ulcerative colitis, duodenal ulcers, and gastric ulcers. It reduces irritation and soothes in cases of irritable cough and bronchitis. At the same, time it acts as an effective expectorant, which relieves respiratory problems by dissolving thick mucus.

Many modern herbalists believe comfrey is safer for use as a topical agent than it is when ingested. Some studies link its internal use to veno-occlusive disease, or VOD, a condition that can cause liver failure. Even when used topically, some experts recommend limiting use to no more than 10 consecutive days and a maximum of four to six weeks in any 12-month period. Consumers are strongly urged to consult with a physician before using this her