Plant Comparison
Pot marigold 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
Pot marigold and Common Comfrey: they share 5 indicated uses (arthritis / joint pain, bruising, inflammation (general), …); 2 pharmacological actions in common.
Evidence face-off — shared uses
| Condition | Pot marigold | Common Comfrey | Verdict |
|---|---|---|---|
| Arthritis / joint pain | 5/10 | 5/10 | Comparable evidence |
| Bruising | 5/10 | 8/10 | Stronger for Common Comfrey |
| Inflammation (general) | 5/10 | 5/10 | Comparable evidence |
| Skin irritation | 5/10 | 5/10 | Comparable evidence |
| Wounds | 5/10 | 5/10 | Comparable evidence |
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
Principal wound-healing and anti-inflammatory constituents of the flower.
Antioxidant flavonoids and carotenoids give the flower its orange-yellow colour and contribute to its antioxidant activity.
Minor aromatic and resinous constituents of the flower head.
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
Calendula officinalis extracts show cytotoxic antitumor, pro-apoptotic and antimetastatic activity across many cancer cell lines and in animal models (preclinical).
Traditional & Indicated Uses
inferred from anti-inflammatory action
A Calendula officinalis (LACE) aqueous extract inhibits proliferation (70-100%) of leukemia, melanoma, breast, prostate, lung and colon cancer cell lines via G0/G1 arrest and caspase-3 apoptosis and inhibits melanoma growth in nude mice; a systematic review documents its cytotoxic and antimetastatic antitumour activity (preclinical).
inferred from antifungal action
inferred from anti-inflammatory 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
Generally very safe for topical use. May cause contact dermatitis in rare cases (Asteraceae family allergy). Internal use is safe in normal doses. Avoid during pregnancy at therapeutic doses (uterine stimulant potential). Generally safe during breastfeeding for topical use.
Duke (2002) rates calendula (Calendula officinalis) and notes anti-inflammatory, wound-healing (vulnerary), antifungal, and antispasmodic activities at experimental levels. Commission E (KOM) approves calendula flower for wound healing and anti-inflammatory uses, both topically and as a gargle. The plant contains flavonoids, triterpene saponins (oleanolic acid glycosides), and essential oils. Dose: 1–2 g dried flower as tea (for mouth rinse/gargle); or as cream/ointment containing 2–5% calendula extract for topical use. Duke notes that calendula is generally very well-tolerated, though Asteraceae sensitivity can occasionally cause allergic reactions (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
Aromatic annual or short-lived perennial herb with soft, hairy, oblong leaves and branching, slightly sticky stems. The flower heads are bright orange to yellow, daisy-like, with numerous narrow ray florets surrounding a darker central disc, opening in sunlight and closing at dusk.[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
Widely cultivated as a garden and medicinal plant; believed native to southern Europe and the Mediterranean, now naturalised in gardens and waste ground worldwide.[1]
Native to Europe and western Asia, growing in damp ground - riverbanks, ditches, damp meadows and waste ground - and widely cultivated.[11]
Harvesting
The flower heads (or just the ray-floret petals) are picked by hand as they open, through the flowering season, and dried quickly in a warm, shaded, airy place to preserve colour and resin content.[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
Calendula flower is one of the most widely used topical wound-healing and skin-soothing herbs in Western herbal medicine, applied to cuts, grazes, minor burns and skin inflammation, and used internally as a gentle anti-inflammatory and antimicrobial remedy and as a gargle for mouth and throat irritation.[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
Dried petals infused in a carrier oil, used as a soothing base for topical creams and balms for skin healing.
Standardised flower extract formulated into a cream or ointment for topical wound and skin care; the best-studied modern form.
Dried flower infused in hot water, 1-2 g in 150 ml, used still warm as a mouth rinse or gargle 2-4 times daily. The EU herbal monograph's posology for this preparation is OROMUCOSAL only - it does not support taking the infusion internally. Educational reference only, not a prescription.
The officially recognised European herbal-monograph preparation, for minor bruises and sprains, short-term use only.
Dosage
The EU herbal monograph gives semi-solid preparations containing the equivalent of 2-10% herbal substance, applied as a thin layer to the affected area 2 to 4 times daily. Educational reference only, not a prescription.
The EU herbal monograph gives 1-2 g of the flower in 150 mL water as an infusion, used still warm for rinsing and gargling 2 to 4 times daily, or to prepare impregnated dressings for the skin. This is an oromucosal and cutaneous preparation, not an oral tea. 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
Not documented
References & Sources
- Givol, O., Kornhaber, R., Visentin, D., Cleary, M. et al (2019) 'A systematic review of Calendula officinalis extract for wound healing', Wound Repair and Regeneration, 27(5), pp. 548-561. doi:10.1111/wrr.12737 Meta-analysis / review
https://doi.org/10.1111/wrr.12737 - Shahane, K., Kshirsagar, M., Tambe, S., Jain, D. et al (2023) 'An Updated Review on the Multifaceted Therapeutic Potential of Calendula officinalis L', Pharmaceuticals (Basel), 16(4), pp. 611. doi:10.3390/ph16040611 Traditional / reference
https://doi.org/10.3390/ph16040611 - Saffari, E., Mohammad-Alizadeh-Charandabi, S., Adibpour, M., Mirghafourvand, M. et al (2016) 'Comparing the effects of Calendula officinalis and clotrimazole on vaginal Candidiasis: A randomized controlled trial', Women & Health, 57(10), pp. 1145-1160. doi:10.1080/03630242.2016.1263272 Randomized trial
https://doi.org/10.1080/03630242.2016.1263272 - Cruceriu, D., Balacescu, O. and Rakosy, E (2018) 'Calendula officinalis: potential roles in cancer treatment and palliative care', Integrative Cancer Therapies, 17(4), pp. 1068-1078. doi:10.1177/1534735418803766 Meta-analysis / review
https://doi.org/10.1177/1534735418803766 - Rezai, S., Rahzani, K., Hekmatpou, D. and Rostami, A (2023) 'Effect of oral Calendula officinalis on second-degree burn wound healing', Scars, Burns & Healing, 9, pp. 20595131221134053. doi:10.1177/20595131221134053 Randomized trial
https://doi.org/10.1177/20595131221134053 - Kadowaki, W., Miyata, R., Mizuno, S., Fujinami, M., Sato, Y. and Kumazawa, S (2023) 'Prenylated acetophenones from the roots of Calendula officinalis and their anti-inflammatory activity', Bioscience, Biotechnology, and Biochemistry, 87(7), pp. 683-687. doi:10.1093/bbb/zbad042 Preclinical
https://doi.org/10.1093/bbb/zbad042 - Samra, R.M., Maatooq, G.T. and Zaki, A.A (2022) 'A new antiprotozoal compound from Calendula officinalis', Natural Product Research, 36(22), pp. 5747-5752. doi:10.1080/14786419.2021.2023868 Preclinical
https://doi.org/10.1080/14786419.2021.2023868 - Kaur, J., Sidhu, S., Chopra, K. and Khan, M.U (2016) 'Calendula officinalis ameliorates l-arginine-induced acute necrotizing pancreatitis in rats', Pharmaceutical Biology, 54(12), pp. 2951-2959. doi:10.1080/13880209.2016.1195848 Preclinical
https://doi.org/10.1080/13880209.2016.1195848 - Aro, A.A., Perez, M.O., Vieira, C.P., Esquisatto, M.A.M., Rodrigues, R.A.F., Gomes, L. and Pimentel, E.R (2014) 'Effect of Calendula officinalis cream on achilles tendon healing', Anatomical Record, 298(2), pp. 428-435. doi:10.1002/ar.23057 Preclinical
https://doi.org/10.1002/ar.23057 - Zhang, X., Wang, R., Finiuk, N., Stoika, R., Lin, H., Wang, X. and Jin, M (2023) 'Active compounds from Calendula officinalis flowers act via PI3K and ERK signaling pathways to offer neuroprotective effects against Parkinson's disease', Food Science & Nutrition, 12(1), pp. 450-458. doi:10.1002/fsn3.3792 Preclinical
https://doi.org/10.1002/fsn3.3792 - Kadowaki, W., Miyata, R., Fujinami, M., Sato, Y. and Kumazawa, S (2023) 'Catechol-O-methyltransferase inhibitors from Calendula officinalis leaf', Molecules, 28(3), pp. 1333. doi:10.3390/molecules28031333 Preclinical
https://doi.org/10.3390/molecules28031333 - European Medicines Agency (HMPC) (2018) 'European Union herbal monograph on Calendula officinalis L., flos, Revision 1'. Available at: https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-calendula-officinalis-l-flos-revision-1_en.pdf Traditional / reference
https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-calendula-officinalis-l-flos-revision-1_en.pdf - Hoffmann, D (2003) 'Medical Herbalism'. Traditional / reference
https://scholar.google.com/scholar?q=Medical%20Herbalism - Nicolaus, C. et al (2017) 'A double-blind, randomized controlled trial to investigate the efficacy and safety of a monograph-based Calendula cream versus a comparator cream', 35(1), pp. 81--89. Randomized trial
https://scholar.google.com/scholar?q=A%20double-blind%2C%20randomized%20controlled%20trial%20to%20investigate%20the%20efficacy%20and%20safety%20of%20a%20monograph-based%20Calendula%20cream%20versus%20a%20comparator%20cream - Preethi, K.C. and Kuttan, R (2009) 'Wound healing activity of flower extract of Calendula officinalis', 20(1), pp. 73--79. doi:10.1515/jbcpp.2009.20.1.73 Preclinical
https://doi.org/10.1515/jbcpp.2009.20.1.73 - Jimenez-Medina, E. and Garcia-Lora, A. and Paco, L. and Algarra, I. and Collado, A. and Garrido, F (2006) 'A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation', BMC Cancer, 6, pp. 119. doi:10.1186/1471-2407-6-119 Preclinical
https://doi.org/10.1186/1471-2407-6-119 - 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
- 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.