Both common comfrey (Symphytum officinale, Boraginaceae) and Russian comfrey (S. × uplandicum, Boraginaceae) have been used for centuries to heal wounds, treat broken bones, aid in tissue repair, cure ulcers, and eliminate pain in muscles and joints.^1,2 Comfrey root has been used to treat insect bites, inflammation, tendinitis, knee joint injuries, and back pain.³ While oral comfrey root is banned in the US due to its pyrrolizidine alkaloids (PAs),³ Native American used it internally to treat many health problems.² In ancient Greece, the herb was used to curtail heavy bleeding and mend broken bones.² Although comfrey contains many compounds, it is thought that allantoin, which stimulates cell growth, and rosmarinic acid may be the most important.³

Several clinical trials have been conducted with a Russian comfrey preparation (Traumaplant^®; Harras Pharma Curarina GmbH; Munich, Germany) made from the fresh aerial portion of the herb. The preparation was tested in wound healing, ankle joint distortion, and back pain (myalgia).^3,4 (See HC 111355-492) The various studies demonstrated that Traumaplant may reduce wound size and healing time, and ameliorate upper back pain and pain due to ankle joint distortion. In an observational study, the product was also found to be effective in treating the symptoms (pain, edema, hematoma, general and functional impairment) of children with blunt force trauma.³

A comfrey root extract (Kytta-Salbe^®f; Merck Selbstmedikation GmbH; Darmstadt, Germany) was found to relieve the pain of knee osteoarthritis in a 3-week clinical trial.⁴ The same preparation was tested against diclofenac gel in patients with acute unilateral ankle strains. While both treatments were rated as excellent, the authors surmised that the comfrey extract may be superior to the diclofenac preparation.⁵ Other clinical trials have also demonstrated Kytta-Salbe's efficacy in treating acute upper or low back pain in conjunction with methyl nicotinate⁶ and alone.⁷

References

¹Staiger C. Comfrey: a clinical overview. Phytother Res. October 2012;26(10):1441-1448.

²Ritchason J. The Little Herb Encyclopedia. Pleasantville Utah: Woodland Health Books; 1995.

³Staiger C. Comfrey root: from tradition to modern clinical trials. Wien Med Wochenschr. February 2013;163(3-4):58-64.

⁴Grube B, Grunwald J, Krug L, Staiger C. Efficacy of a comfrey root (Symphyti offic. radix) extract ointment in the treatment of patients with painful osteoarthritis of the knee: results of a double-blind, randomised, bicenter, placebo-controlled trial. Phytomed. 2007;14(1):2-10.

⁵Predel H, Giannetti B, Koll R, Bulitta M, Staiger C. Efficacy of a comfrey root extract ointment in comparison to a Diclofenac gel in the treatment of ankle distortions: results of an observer-blinded, randomized, multicenter study. Phytomed. 2005;12:707-714.

⁶Pabst H, Schaefer A, Staiger C, Junker-Samek M, Predel HG. Combination of comfrey root extract plus methyl nicotinate in patients with conditions of acute upper or low back pain: a multicentre randomised controlled trial. Phytother Res. June 2013;27(6):811-817.

Lori Glenn,  Managing Editor