TempoLife › Fonctions › Herb and spice reference: evidence, dose and interactions › comfrey
Comfrey
Comfrey — ce que la monographie européenne soutient réellement, ce à quoi ce n’est pas destiné, la forme et la durée prévue, les effets indésirables, et le 1 interaction médicamenteuse documentée.
Ceci est une page de référence, pas un diagnostic ni une ordonnance. Les produits à base de plantes sont de la vraie pharmacologie : effets, effets indésirables et interactions. Dites à votre médecin et à votre pharmacien tout ce que vous prenez, thés et compléments compris, et n’arrêtez ni ne changez jamais un médicament prescrit à cause de ce que vous lisez ici.
Ce que c’est
Symphytum officinale L. — root and leaf
Noms locaux dans la région que ce site dessert :varemerohi (ET) · rohtoraunioyrtti (FI) · окопник (RU).
Groupé ici sous Where the harm is. Position réglementaire :External use only, with limits; oral preparations are not acceptable in the EU.
Ce que les preuves soutiennent
L’indication enregistrée :External use on unbroken skin for bruises, sprains and strains, in pyrrolizidine-alkaloid-depleted preparations.
Comfrey is the clearest case of a traditional remedy that modern chemistry ruled out for internal use. It contains pyrrolizidine alkaloids, which the liver converts into reactive compounds that damage the small hepatic veins and cause hepatic veno-occlusive disease (sinusoidal obstruction syndrome); they are also genotoxic and carcinogenic in animal studies. Oral comfrey preparations were withdrawn in Europe decades ago on that basis. Externally, comfrey creams and ointments for bruises and sprains remain in use and have reasonable trial support for pain relief, but regulators restrict them to alkaloid-depleted preparations, intact skin only, and a limited number of days of use per year — because pyrrolizidine alkaloids are absorbed through skin. The wider lesson is that this is not a comfrey-only problem: the same alkaloids occur in ragwort, borage, butterbur and coltsfoot, and they contaminate herbal teas and honey when alkaloid-containing weeds are harvested with the crop. European food law sets maximum levels for pyrrolizidine alkaloids in herbal teas, teas, certain herbs and food supplements for exactly that reason.
D — Popular claim unsupported, or safety dominates The better trials are negative, or the substance appears in the literature mainly for the harm it has caused.
Ce à quoi ce n’est pas destiné
Swallowing, in any form, including comfrey tea and "knitbone" infusions. Also not for open wounds, broken skin or grazes.
Forme, force et durée
Creams, ointments and gels of alkaloid-depleted root or leaf extract, for external use on unbroken skin.
Durée.Limited courses, and a limited total number of days per year — the restriction is on cumulative exposure, not on any single application.
Aucun chiffre en grammes n’apparaît sur cette page exprès. La partie de plante, le solvant d’extraction et le rapport drogue-extrait définissent ensemble une préparation, et un nombre pris à l’une ne décrit pas l’autre. Le raisonnement est exposé sur le hub ; la quantité qui s’applique à vous est celle imprimée sur le paquet que vous tenez, et un pharmacien la lira avec vous.
Effets indésirables
Externally, occasional skin irritation and contact allergy. Internally, liver injury that can be severe and irreversible.
Qui devrait l’éviter
Never in pregnancy or while breastfeeding. Not on children. Not with existing liver disease.
Interactions avec les médicaments
| Médicament ou substance | Ce qui est décrit |
|---|---|
| Anything else that stresses the liver | Anything else that burdens the liver — alcohol, other pyrrolizidine-containing plants, medicines with a hepatic signal — adds to the same target organ. |
La vue inverse — partir du médicament plutôt que de la plante — est dans la référence des interactions médicaments, aliments et alcool, et résumé pour chaque plante de ce site.
Sources :European Medicines Agency — Committee on Herbal Medicinal Products (HMPC), European Union herbal monographs · LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (NIDDK, National Institutes of Health)· vérifié2026-09-06
Questions fréquentes
À quoi sert comfrey ?
External use on unbroken skin for bruises, sprains and strains, in pyrrolizidine-alkaloid-depleted preparations. Comfrey is the clearest case of a traditional remedy that modern chemistry ruled out for internal use. It contains pyrrolizidine alkaloids, which the liver converts into reactive compounds that damage the small hepatic veins and cause hepatic veno-occlusive disease (sinusoidal obstruction syndrome); they are also genotoxic and carcinogenic in animal studies. Oral comfrey preparations were withdrawn in Europe decades ago on that basis. Externally, comfrey creams and ointments for bruises and sprains remain in use and have reasonable trial support for pain relief, but regulators restrict them to alkaloid-depleted preparations, intact skin only, and a limited number of days of use per year — because pyrrolizidine alkaloids are absorbed through skin. The wider lesson is that this is not a comfrey-only problem: the same alkaloids occur in ragwort, borage, butterbur and coltsfoot, and they contaminate herbal teas and honey when alkaloid-containing weeds are harvested with the crop. European food law sets maximum levels for pyrrolizidine alkaloids in herbal teas, teas, certain herbs and food supplements for exactly that reason.
Est-ce que comfrey marche ?
Noté ici D : The better trials are negative, or the substance appears in the literature mainly for the harm it has caused. Swallowing, in any form, including comfrey tea and "knitbone" infusions. Also not for open wounds, broken skin or grazes.
Combien de comfrey dois-je prendre ?
Cette référence n’imprime pas de chiffres en grammes, car ils ne se transférent pas entre préparations de force d’extrait différente. Ce qu’on peut dire honnêtement, c’est la forme et la durée :Creams, ointments and gels of alkaloid-depleted root or leaf extract, for external use on unbroken skin. Limited courses, and a limited total number of days per year — the restriction is on cumulative exposure, not on any single application.
Quels sont les effets indésirables de comfrey ?
Externally, occasional skin irritation and contact allergy. Internally, liver injury that can be severe and irreversible.
Est-ce que comfrey interagit avec des médicaments ?
Oui — documenté pourLiver load. Chacune est décrite sur cette page, avec un lien vers la référence côté médicament s’il en existe une.
Autres danswhere the harm is
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