Plant Comparison
Borage vs Common Comfrey
A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.
At a glance
Borage and Common Comfrey: both belong to the Boraginaceae family; they share 6 indicated uses (arthritis / joint pain, back pain, headache, …); 2 pharmacological actions in common.
Evidence face-off — shared uses
| Condition | Borage | Common Comfrey | Verdict |
|---|---|---|---|
| Arthritis / joint pain | 1/10 | 5/10 | Stronger for Common Comfrey |
| Back pain | 1/10 | 5/10 | Stronger for Common Comfrey |
| Headache | 1/10 | 5/10 | Stronger for Common Comfrey |
| Inflammation (general) | 1/10 | 5/10 | Stronger for Common Comfrey |
| Pain (general) | 1/10 | 8/10 | Stronger for Common Comfrey |
| Skin irritation | 1/10 | 5/10 | Stronger for Common Comfrey |
Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.
Key Constituents
Borage seed oil has one of the highest known GLA contents of any plant oil (typically 20-26%), the basis of its anti-inflammatory reputation.
Unsaturated pyrrolizidine alkaloids present in the whole herb are hepatotoxic and genotoxic on cumulative exposure, limiting internal whole-herb use; the refined seed oil is largely free of them.
Contribute to the plant's traditional demulcent and astringent properties.
The key cell-proliferative constituent underlying comfrey's wound-healing reputation.
Contribute to the soothing, demulcent texture of the leaf and root.
Contribute to antioxidant and anti-inflammatory activity.
Hepatotoxic constituents naturally present in the whole plant; the reason internal use is not recommended and processed/detoxified extracts are used for research.
Pharmacological Actions
Traditional & Indicated Uses
inferred from anti-inflammatory action
inferred from anticancer action
inferred from immunomodulator action
inferred from digestive action
inferred from anti-inflammatory action
inferred from anti-inflammatory action
inferred from anti-inflammatory action
inferred from anti-inflammatory action
inferred from anti-oedematous action
Safety, Cautions & Contraindications
Pyrrolizidine alkaloids (PAs): Many Boraginaceae can produce PAs; unsaturated PAs are hepatotoxic and genotoxic (risk increases with cumulative exposure). Borage as food/tea: PA presence in borage consumed as herb/tea has been specifically studied; EU has set PA maximum levels for certain foods including borage (context for why sourcing/limits matter). Pregnancy/breastfeeding: avoid internal use of borage herb products due to PA-related concerns and risk uncertainty. Liver disease / long-term use: avoid (PA risk + cumulative exposure logic). Seed oil vs herb: refined/quality-controlled seed oil is generally the preferred form when borage is used medicinally, because the main target compound is GLA; however, product quality and contamination control still matter. Drug interactions (caution): GLA oils have been discussed with anticoagulants (bleeding risk caution is better established for evening primrose oil; borage oil is often grouped in the same “GLA oil” category). Use caution if on anticoagulants/antiplatelets.
Duke (2002) rates borage as a single-plus herb (+) with predominantly folklore-level evidence. Borage seed oil is rich in gamma-linolenic acid (GLA) and has been used for inflammatory conditions such as arthritis and PMS, and for cardiovascular support; typical dose is one 300 mg softgel containing 24% GLA or 2-4 ml liquid leaf extract. Commission E does not approve borage for any indication, and the herb contains hepatotoxic and carcinogenic pyrrolizidine alkaloids, making long-term use inadvisable (Duke, 2002).
Big headline: Comfrey naturally contains pyrrolizidine alkaloids (PAs), which can seriously harm the liver if taken internally (Staiger, 2012; EMA, 2015). • Do not ingest comfrey (no teas, no internal tinctures, no capsules), because PA exposure from internal use is the main safety problem (Staiger, 2012; Bach et al., 1990). • Topical use only, short-term: EU herbal guidance describes comfrey root preparations for minor bruises and sprains in adults, and recommends limited duration (commonly up to about 10 days) (EMA, 2015; EMA/HMPC, 2024). • Do not apply to broken skin (open wounds, damaged/irritated skin) and avoid eyes/mucous membranes (EMA/HMPC, 2024). • Pregnancy & breastfeeding: best avoided (not enough safety margin for medicinal use) (EMA/HMPC, 2024). • Children/adolescents: not recommended for medicinal topical use in EU monograph context (EMA/HMPC, 2024). • If you have liver disease or take medicines that stress the liver, skip comfrey completely (risk management logic based on PA concern) (Staiger, 2012; EMA, 2015). • Skin reactions: mild rash/irritation can occur; stop if it irritates (Smith and Jacobson, 2011).
Duke (2002) classifies common comfrey (Symphytum officinale) with anti-inflammatory and wound-healing properties, supported by allantoin content (promotes cell proliferation). However, comfrey also contains hepatotoxic pyrrolizidine alkaloids. Internal use is no longer recommended, and Commission E approved only external use. Duke emphasizes that pyrrolizidine alkaloids are cumulative hepatotoxins associated with veno-occlusive disease, and prolonged or internal use is contraindicated (Duke, 2002).
External Ids
Botanical Description
Robust, bristly annual herb with hollow, branching stems covered in coarse, stiff hairs. The leaves are large, oval and wrinkled, also coarsely hairy, and smell of cucumber when crushed. The flowers are strikingly bright blue, star-shaped with five pointed petals and a prominent black central cone of anthers, borne in nodding clusters.[1]
Robust, hairy perennial herb (Boraginaceae), 60-120 cm tall, with a thick, black-skinned, mucilaginous taproot. Leaves are large, broad, lance-shaped and bristly-hairy, running down the stem as raised wings (decurrent) - the leaf base's smooth, untoothed margin is a key feature distinguishing it from toxic foxglove. Drooping clusters of tubular, bell-shaped flowers are cream, pink or purple depending on variety.[11]
Habitat
Grows readily on disturbed, nutrient-rich ground, gardens, waste places and field margins; native to the Mediterranean region and widely naturalised and cultivated across Europe and elsewhere as a culinary and oil-seed crop.[1]
Native to Europe and western Asia, growing in damp ground - riverbanks, ditches, damp meadows and waste ground - and widely cultivated.[11]
Harvesting
Leaves and flowers are picked fresh through the growing season, at their best just as the flowers open; the seed is collected in late summer once the seed heads have dried, pressed for its gamma-linolenic-acid-rich oil.[1]
Leaves are cut during the growing season (before flowering is often preferred for lower pyrrolizidine-alkaloid content); root is dug in autumn or spring from mature plants.[11]
Traditional Uses
Borage has a long folk reputation, reflected in the old saying 'borage for courage', as a mood-lifting, cooling herb for feverish colds and respiratory complaints, and as a digestive and anti-inflammatory remedy; the fresh leaves and flowers have also been used culinarily. Modern use is centred on the seed oil, rich in gamma-linolenic acid (GLA), for inflammatory and skin conditions.[1]
Comfrey has one of the strongest traditional reputations of any European herb for wound healing and bone/tissue repair - the folk names 'knitbone' and 'boneset' reflect this - owing to its high allantoin content, which stimulates cell proliferation. Because the plant also contains hepatotoxic pyrrolizidine alkaloids, modern regulatory use is restricted to topical preparations only, for minor bruises and sprains, and internal use (teas, tinctures) is no longer recommended.[11]
Preparations
The officially recognised European herbal-monograph preparation, for minor bruises and sprains, short-term use only.
Dosage
A phase-two randomised placebo-controlled trial in moderate persistent asthma used Borago officinalis extract at 5 mL three times daily for one month. Because of pyrrolizidine alkaloid content, whole-herb (leaf/flower) preparations should only be used short-term and from PA-controlled sources; avoid in pregnancy, breastfeeding and liver disease. Educational reference only, not a prescription.
EU herbal-monograph guidance describes comfrey root preparations applied topically for minor bruises and sprains in adults, for a limited duration (commonly up to about 10 days); do not apply to broken skin or near eyes/mucous membranes. Comfrey must never be taken internally (no teas, tinctures or capsules) because of its pyrrolizidine alkaloid content. Educational reference only, not a prescription.
References
Lookalikes Review
Dangerous Lookalikes
References & Sources
- Slama, M., Slougui, N., Benaissa, A., Nekkaa, A. et al (2024) 'Borago officinalis L.: A Review on Extraction, Phytochemical, and Pharmacological Activities', Chemistry & Biodiversity, 21(5), pp. e202301822. doi:10.1002/cbdv.202301822 Traditional / reference
https://doi.org/10.1002/cbdv.202301822 - Michalak, M., Zagórska-Dziok, M., Klimek-Szczykutowicz, M. and Szopa, A (2023) 'Phenolic Profile and Comparison of the Antioxidant, Anti-Ageing, Anti-Inflammatory, and Protective Activities of Borago officinalis Extracts on Skin Cells', Molecules, 28(2), pp. 868. doi:10.3390/molecules28020868 Preclinical
https://doi.org/10.3390/molecules28020868 - Ghasemian, M., Owlia, S. and Owlia, M.B (2016) 'Review of Anti-Inflammatory Herbal Medicines', Advances in Pharmacological Sciences, 2016, pp. 9130979. doi:10.1155/2016/9130979 Traditional / reference
https://doi.org/10.1155/2016/9130979 - Di Cerbo, A., Carnevale, G., Avallone, R., Zavatti, M. and Corsi, L (2020) 'Protective Effects of Borago officinalis (Borago) on Cold Restraint Stress-Induced Gastric Ulcers in Rats: A Pilot Study', Frontiers in Veterinary Science, 7, pp. 427. doi:10.3389/fvets.2020.00427 Preclinical
https://doi.org/10.3389/fvets.2020.00427 - Seo, S.A., Park, B., Hwang, E., Park, S. and Yi, T (2018) 'Borago officinalis L. attenuates UVB-induced skin photodamage via regulation of AP-1 and Nrf2/ARE pathway in normal human dermal fibroblasts and promotion of collagen synthesis in hairless mice', Experimental Gerontology, 107, pp. 178-186. doi:10.1016/j.exger.2018.02.017 Preclinical
https://doi.org/10.1016/j.exger.2018.02.017 - Mirsadraee, M., Khashkhashi Moghaddam, S., Saeedi, P. and Ghaffari, S (2016) 'Effect of Borago Officinalis Extract on Moderate Persistent Asthma: A Phase two Randomized, Double Blind, Placebo-Controlled Clinical Trial', Tanaffos, 15(3), pp. 168-174. doi:10.1183/13993003.congress-2016.pa4116 Randomized trial
https://doi.org/10.1183/13993003.congress-2016.pa4116 - Lozano-Baena, M., Tasset, I., Munoz-Serrano, A., Alonso-Moraga, A. and de Haro-Bailon, A (2016) 'Cancer Prevention and Health Benefices of Traditionally Consumed Borago officinalis Plants', Nutrients, 8(1), pp. 48. doi:10.3390/nu8010048 Preclinical
https://doi.org/10.3390/nu8010048 - Rodriguez-Magana, M.P., Cordero-Perez, P., Rivas-Morales, C., Oranday-Cardenas, M.A., Moreno-Pena, D.P., Garcia-Hernandez, D.G. and Leos-Rivas, C (2019) 'Hypoglycemic Activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on Wistar Rats', Journal of Diabetes Research, 2019, pp. 7836820. doi:10.1155/2019/7836820 Preclinical
https://doi.org/10.1155/2019/7836820 - Navarro-Herrera, D., Aranaz, P., Eder-Azanza, L., Zabala, M., Romo-Hualde, A., Hurtado, C., Calavia, D., Lopez-Yoldi, M., Martinez, J.A., Gonzalez-Navarro, C.J. and Vizmanos, J.L (2018) 'Borago officinalis seed oil (BSO), a natural source of omega-6 fatty acids, attenuates fat accumulation by activating peroxisomal beta-oxidation both in C. elegans and in diet-induced obese rats', Food & Function, 9(8), pp. 4340-4351. doi:10.1039/c8fo00423d Preclinical
https://doi.org/10.1039/c8fo00423d - Moliner, C., Casedas, G., Barros, L., Finimundy, T.C., Gomez-Rincon, C. and Lopez, V (2022) 'Neuroprotective Profile of Edible Flowers of Borage (Borago officinalis L.) in Two Different Models: Caenorhabditis elegans and Neuro-2a Cells', Antioxidants, 11(7), pp. 1244. doi:10.3390/antiox11071244 Preclinical
https://doi.org/10.3390/antiox11071244 - Samy, M.N., Hamed, A.N.E., Sugimoto, S., Otsuka, H., Kamel, M.S. and Matsunami, K (2015) 'Officinalioside, a new lignan glucoside from Borago officinalis L', Natural Product Research, 30(8), pp. 967-972. doi:10.1080/14786419.2015.1088540 Preclinical
https://doi.org/10.1080/14786419.2015.1088540 - Yue, Y., Jin, F. and Yue, X (2021) 'The effect of Borago officinalis on the signaling pathway of the NLRP3 inflammasome complex, TLR4 and some inflammatory cytokines in type II diabetic patients with acute respiratory distress syndrome', Cellular and Molecular Biology, 67(3), pp. 178-183. doi:10.14715/cmb/2021.67.3.28 Clinical study
https://doi.org/10.14715/cmb/2021.67.3.28 - Fernandes, L., Pereira, J.A., Saraiva, J.A., Ramalhosa, E. and Casal, S (2019) 'Phytochemical characterization of Borago officinalis L. and Centaurea cyanus L. during flower development', Food Research International, 123, pp. 771-778. doi:10.1016/j.foodres.2019.05.014 Preclinical
https://doi.org/10.1016/j.foodres.2019.05.014 - European Medicines Agency (HMPC) (2021) 'Public statement on the use of herbal medicinal products containing toxic, unsaturated pyrrolizidine alkaloids (PAs), including recommendations regarding contamination of herbal medicinal products with PAs, Revision 1'. Available at: https://www.ema.europa.eu/en/documents/public-statement/public-statement-use-herbal-medicinal-products-containing-toxic-unsaturated-pyrrolizidine-alkaloids-pas-including-recommendations-regarding-contamination-herbal-medicinal-products-pyrrolizidine_en.pdf Traditional / reference
https://www.ema.europa.eu/en/documents/public-statement/public-statement-use-herbal-medicinal-products-containing-toxic-unsaturated-pyrrolizidine-alkaloids-pas-including-recommendations-regarding-contamination-herbal-medicinal-products-pyrrolizidine_en.pdf - Kapoor, R. and Huang, Y.S (2006) 'Gamma linolenic acid: an antiinflammatory omega-6 fatty acid', 7(6), pp. 531--534. doi:10.2174/138920106779116874 Traditional / reference
https://doi.org/10.2174/138920106779116874 - Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
https://powo.science.kew.org - World Health Organization (2002) 'WHO Monographs on Selected Medicinal Plants'. Traditional / reference
https://scholar.google.com/scholar?q=WHO%20Monographs%20on%20Selected%20Medicinal%20Plants - Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition - Negroni, M.S., Marengo, A., Caruso, D., et al (2019) 'A case report of accidental intoxication following ingestion of foxglove confused with borage: high digoxinemia without major complications', Case Reports in Cardiology, 2019, pp. 9707428. doi:10.1155/2019/9707428 Clinical study
https://doi.org/10.1155/2019/9707428 - Iraci, F. and Herdeg, C. and Holzwarth, M. and Storz, M.A (2023) 'Of mixed vegetables and cardiac arrhythmias - Digitalis purpurea confused with Borago officinalis: a case series of accidental digitoxin intoxications', Journal of Cardiology Cases, 28(2), pp. 86-90. doi:10.1016/j.jccase.2023.04.007 Clinical study
https://doi.org/10.1016/j.jccase.2023.04.007
- Syarifah, A.N., Suryadi, H., Hayun, H., Simamora, A. and others (2023) 'Detoxification of comfrey (Symphytum officinale L.) extract using natural deep eutectic solvent (NADES) and evaluation of its anti-inflammatory, antioxidant, and hepatoprotective properties', Frontiers in Pharmacology, 14, pp. 1012716. doi:10.3389/fphar.2023.1012716 Preclinical
https://doi.org/10.3389/fphar.2023.1012716 - Melnyk, N., Popowski, D., Strawa, J.W., Przygodzinska, K. and others (2023) 'Skin microbiota metabolism of natural products from comfrey root (Symphytum officinale L.)', Journal of Ethnopharmacology, 318(Pt B), pp. 116968. doi:10.1016/j.jep.2023.116968 Preclinical
https://doi.org/10.1016/j.jep.2023.116968 - Trifan, A., Skalicka-Wozniak, K., Granica, S., Czerwinska, M.E. and others (2020) 'Symphytum officinale L.: Liquid-liquid chromatography isolation of caffeic acid oligomers and evaluation of their influence on pro-inflammatory cytokine release in LPS-stimulated neutrophils', Journal of Ethnopharmacology, 262, pp. 113169. doi:10.1016/j.jep.2020.113169 Preclinical
https://doi.org/10.1016/j.jep.2020.113169 - Brown, A.W., Stegelmeier, B.L., Colegate, S.M., Gardner, D.R. and others (2016) 'The comparative toxicity of a reduced, crude comfrey (Symphytum officinale) alkaloid extract and the pure, comfrey-derived pyrrolizidine alkaloids, lycopsamine and intermedine in chicks (Gallus gallus domesticus)', Journal of Applied Toxicology, 36(5), pp. 716-725. doi:10.1002/jat.3205 Preclinical
https://doi.org/10.1002/jat.3205 - Trifan, A., Wolfram, E., Esslinger, N., Grubelnik, A. and others (2021) 'Globoidnan A, rabdosiin and globoidnan B as new phenolic markers in European-sourced comfrey (Symphytum officinale L.) root samples', Phytochemical Analysis, 32(4), pp. 482-494. doi:10.1002/pca.2996 Preclinical
https://doi.org/10.1002/pca.2996 - Nastic, N., Borras-Linares, I., Lozano-Sanchez, J., Svarc-Gajic, J. and others (2020) 'Comparative Assessment of Phytochemical Profiles of Comfrey (Symphytum officinale L.) Root Extracts Obtained by Different Extraction Techniques', Molecules, 25(4), pp. 837. doi:10.3390/molecules25040837 Preclinical
https://doi.org/10.3390/molecules25040837 - Frost, R., MacPherson, H. and O'Meara, S (2013) 'A critical scoping review of external uses of comfrey (Symphytum spp.)', Complementary Therapies in Medicine, 21(6), pp. 724-745. doi:10.1016/j.ctim.2013.09.009 Meta-analysis / review
https://doi.org/10.1016/j.ctim.2013.09.009 - Trifan, A., Opitz, S.E.W., Josuran, R., Grubelnik, A. and others (2018) 'Is comfrey root more than toxic pyrrolizidine alkaloids? Salvianolic acids among antioxidant polyphenols in comfrey (Symphytum officinale L.) roots', Food and Chemical Toxicology, 112, pp. 178-187. doi:10.1016/j.fct.2017.12.051 Preclinical
https://doi.org/10.1016/j.fct.2017.12.051 - Dey, D., Jingar, P., Agrawal, S., Shrivastava, V. and others (2019) 'Symphytum officinale augments osteogenesis in human bone marrow-derived mesenchymal stem cells in vitro as they differentiate into osteoblasts', Journal of Ethnopharmacology, 248, pp. 112329. doi:10.1016/j.jep.2019.112329 Preclinical
https://doi.org/10.1016/j.jep.2019.112329 - Kuchta, K. and Schmidt, M (2020) 'Safety of medicinal comfrey cream preparations (Symphytum officinale s.l.): The pyrrolizidine alkaloid lycopsamine is poorly absorbed through human skin', Regulatory Toxicology and Pharmacology, 118, pp. 104784. doi:10.1016/j.yrtph.2020.104784 Preclinical
https://doi.org/10.1016/j.yrtph.2020.104784 - European Medicines Agency (2011) 'European Union herbal monograph on Symphytum officinale L., radix'. Traditional / reference
https://scholar.google.com/scholar?q=European%20Union%20herbal%20monograph%20on%20Symphytum%20officinale%20L.%2C%20radix - Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
https://powo.science.kew.org - Staiger, C (2012) 'Comfrey: a clinical overview', 26(10), pp. 1441--1448. doi:10.1002/ptr.4612 Randomized trial
https://doi.org/10.1002/ptr.4612 - Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition - Vithayathil, M.K. and Edwards, M (2016) 'Comfrey herbal remedy causing second-degree heart block: do not be outfoxed by digitalis', BMJ Case Reports, 2016, pp. bcr2016216995. doi:10.1136/bcr-2016-216995 Clinical study
https://doi.org/10.1136/bcr-2016-216995 - Lin, C.C. and Yang, C.C. and Phua, D.H. and Deng, J.F. and Lu, L.H (2010) 'An outbreak of foxglove leaf poisoning', Journal of the Chinese Medical Association, 73(2), pp. 97-100. doi:10.1016/S1726-4901(10)70009-5 Clinical study
https://doi.org/10.1016/S1726-4901(10)70009-5 - Woodland Trust (2024) 'Foxglove (Digitalis purpurea)'. Available at: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/foxglove/ Traditional / reference
https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/foxglove/
Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.