Comfrey (in German “Beinwell”), like borage, belongs to the roughleaf family (Boraginaceae) and looks very similar to borage. There are a whole range of regional subspecies. Symphytum officinale is grown as a medicinal plant. The name "Beinwell" alone suggests that the substance is said to have a good effect on the bones. The traditional use is mainly in the healing of bone fractures and injuries. This is where the term Symphyton (cohesion plant) is derived from (Ancient Greek by Dioscorides: Symphyton állo (σύμφυτον ἄλλο)).
Allantoin (an imidazolidine derivative), phenolic acids (rosmarinic acid, hydroxycinnamic acid), naphtoquinones (shikonin) and flavanoids are mentioned as potentially active constituents. These are components of a number of phytopharmaceuticals and the effect of the individual substances on in-vitro tests and arthritis models is widely reported [4, 5, 6, 7] [10, 11].
Comfrey preparations are sold as externals, drops and globules and sold as plants for one's own "medicinal garden" for self-cultivation. However, it is also widely used in the cultivated landscape. The root is mainly used.
8 active ingredients are listed in the MMI Pharma Index (comfrey leaves-, -flower-, -root extract, comfrey leaf extract, comfrey herb pressed juice (3-8:1), comfrey pressed juice residue extract (3-10:1); extracting agents: ethanol 30% (V/V), comfrey herb preparation (2-3:1), comfrey root ethanol. decoction, comfrey root extract, comfrey root, FE o.w.A)
As a pharmacy-only medicine, comfrey is available in the following preparations:
The other 40 preparations (as of 12/25) are listed as care products alone and also in numerous combinations.
A Pub-Med search for scientific articles on the keyword "Comfrey" yielded (as of 12.5.2025) 219 references, 8 of which were simultaneously mentioned as "arthritis". There were 308 references for the keyword "Symphytum", 5 of which are with "arthritis". There are 2 analyses of clinical studies for injuries (especially sprains), gonarthrosis and back pain, although the quality of the studies was not satisfactory [2, 8, 9]. Studies on efficacy in patients with inflammatory rheumatic diseases are not found in the primary literature or cited in the reviews. The currently given indications are therefore limited to the diseases mentioned above.
A comparison of the superficial use of comfrey extract and diclofenac for joint injuries showed at least an equivalent effect [1].
In a study with 220 patients with gonarthrosis, pain relief was observed without an increase in side effects compared to placebo. After 3 weeks, pain was 83.5/100 with placebo, comfrey reduced pain by a mean of 41.5 points (MD -41.5, 95% CI -48 to -34). An influence on knee function was not reported in the study. 6% (7/110) with comfrey and 14% (15/110) in the placebo arm (RR 0.47, 95% CI 0.20 to 1.10) reported side effects [3].
Data from use in humans with inflammatory rheumatic diseases are not available. The blanket transfer of efficacy to rheumatoid arthritis or other diseases from animal experiments by individual authors [4] has not been proven.
Data from external use in ankle sprains, non-specific back pain and gonarthrosis suggest the possibility of external application for pain relief. Standardised preparations are available for this purpose. However, a recommendation on topical phytotherapeutics could not be given in the current German guideline on knee osteoarthritis.
Comfrey, like borage, contains pyrolizidine alkaloids, which can be harmful to the liver and carcinogenic. Commission E has therefore only permitted the use of comfrey as a medicinal plant in Germany under restrictions. The maximum daily dose of pyrozolines is 100mg, doses of 10-100mg should be limited to 4-6 weeks/year. New, purified preparations are usually below the dose of 10mg/day, which is classified as harmless, when used properly and are therefore not restricted 1. Nevertheless, a special assessment of benefits and risks should be carried out in children and pregnant women.
1 Monograph BGA/BfArM (Commission E) Date of publication Federal Gazette: 27.7.1990., Issue number: 138., ATC code: D11AG.
There is insufficient scientific evidence to recommend the prescription and use of comfrey preparations for patients with symptoms due to an inflammatory rheumatic disease.
The effects of components of comfrey extracts on inflammatory mediators in vitro and in animal arthritis models do not allow any conclusions to be drawn that anti-inflammatory components of the plant are effective in vivo in humans. Systematic controlled clinical studies on case collectives with clearly defined rheumatological disease patterns are not available.
The current guideline for the treatment of knee osteoarthritis also does not recommend topical therapy.
If patients wish to be treated for osteoarthritis pain, sprains and non-specific back pain, self-initiated treatment with the commercially available creams made from comfrey root preparations does not have to be discouraged.
tment of patients with painful osteoarthritis of the knee: results of a double-blind, randomised, bicenter, placebo-controlled trial. Phytomedicine 14:2-10
4. Li J, Pang J, Liu Z et al. (2021) Shikonin induces programmed death of fibroblast synovial cells in rheumatoid arthritis by inhibiting energy pathways. Sci Rep 11:18263
5. Mahmoudzadeh E, Nazemiyeh H, Hamedeyazdan S (2022) Anti-inflammatory Properties of the Genus Symphytum L.: A Review. Iran J Pharm Res 21:E123949
6. Salehi B, Sharopov F, Boyunegmez Tumer T et al. (2019) Symphytum Species: A Comprehensive Review on Chemical Composition, Food Applications and Phytopharmacology. Molecules 24
7. Seigner J, Junker-Samek M, Plaza A et al. (2019) A Symphytum officinale Root Extract Exerts Anti-inflammatory Properties by Affecting Two Distinct Steps of NF-kappaB Signaling. Front Pharmacol 10:289
8. Staiger C (2013) Comfrey root: from tradition to modern clinical trials. Wien Med Wochenschr 163:58-64
9. Staiger C (2012) Comfrey: a clinical overview. Phytother Res 26:1441-1448
10. Vostinaru O, Conea S, Mogosan C et al. (2018) Anti-inflammatory and antinociceptive effect of root. Rom Biotech Lett 23:14160-14167
11. Wang XH, Shen CP, Wang TT et al. (2024) Shikonin suppresses rheumatoid arthritis by inducing apoptosis and autophagy via modulation of the AMPK/mTOR/ULK-1 signaling pathway. Phytomedicine 128:155512
Last updated: September 28, 2024