TempoLife › Fonctions › Herb and spice reference: evidence, dose and interactions › green-tea-extract
Green tea extract
Green tea extract — 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 3 interaction médicamenteuses 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
Camellia sinensis (L.) Kuntze — leaf; concentrated catechin extracts
Noms locaux dans la région que ce site dessert :roheline tee (ET) · vihreä tee (FI) · зелёный чай (RU).
Groupé ici sous Kitchen spices with a safety story. Position réglementaire :Drinking tea is a food; concentrated extracts are food supplements with an EFSA safety assessment.
Ce que les preuves soutiennent
L’indication enregistrée :Marketed for weight loss and metabolism. Neither claim survives review.
The gap between the drink and the capsule is the entire story here. Drinking green tea is not associated with liver harm and is a perfectly ordinary part of a diet. Concentrated green-tea extracts, sold for weight loss and metabolism, are a different exposure altogether: EFSA assessed them and concluded that catechin doses at or above 800 mg of EGCG a day taken as a food supplement have been shown in trials to raise liver transaminases — a marker of liver stress — and that a safe level for supplements could not be established from the available data. Green-tea extract is among the more frequently implicated botanicals in registries of herb-induced liver injury, and taking it on an empty stomach appears to raise absorption and risk. On the weight-loss claim, the effect measured in trials is too small to matter to anyone.
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
Weight loss, and any liver purpose whatsoever — this is one of the botanicals most likely to injure a liver, not support one.
Forme, force et durée
Brewed leaf tea (a food), and concentrated catechin extracts in capsules, often combined with caffeine in "fat burner" products.
Durée.For extracts, the honest answer is that no safe long-term intake has been established.
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
From tea, the effects of caffeine. From extracts, liver injury: dark urine, yellow eyes or skin, itching, unusual fatigue, pain under the right ribs. Stop immediately and seek medical care if those appear. Nausea and stomach upset are common, particularly fasted.
Qui devrait l’éviter
Avoid extracts with any liver condition, in pregnancy and while breastfeeding. Anyone taking a supplement with an unexplained rise in liver enzymes should stop it and tell their doctor what they were taking.
Interactions avec les médicaments
| Médicament ou substance | Ce qui est décrit |
|---|---|
| Anything else that stresses the liver | Stacking a green-tea extract with alcohol or with other substances that stress the liver is the pattern behind many of the reported cases. |
| Iron supplements and iron-rich meals | Tea polyphenols bind non-haem iron and measurably reduce how much iron is absorbed from a meal taken with tea. If you are being treated for iron deficiency, take iron and tea well apart. |
| Anticoagulants and antiplatelets (warfarin, DOACs, aspirin, clopidogrel) | Green tea leaf contains vitamin K, and large changes in intake have been reported to affect warfarin control. As with all the vitamin K foods, steady intake is what matters, not avoidance. |
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.
En tant qu’aliment
Celui-ci est aussi en cuisine, donc les chiffres nutritionnels valent d’être à côté de la pharmacologie : voir la page de données alimentaires pour calories et nutriments pour 100 g et par portion. Les quantités culinaires et les préparations médicinales sont des expositions différentes, et la différence est souvent toute l’histoire de sécurité.
Sources :European Food Safety Authority — scientific opinions on coumarin, green tea catechins and hydroxyanthracene derivatives · LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (NIDDK, National Institutes of Health) · NIH National Center for Complementary and Integrative Health — herb fact sheets· vérifié2026-09-06
Questions fréquentes
À quoi sert green tea extract ?
Marketed for weight loss and metabolism. Neither claim survives review. The gap between the drink and the capsule is the entire story here. Drinking green tea is not associated with liver harm and is a perfectly ordinary part of a diet. Concentrated green-tea extracts, sold for weight loss and metabolism, are a different exposure altogether: EFSA assessed them and concluded that catechin doses at or above 800 mg of EGCG a day taken as a food supplement have been shown in trials to raise liver transaminases — a marker of liver stress — and that a safe level for supplements could not be established from the available data. Green-tea extract is among the more frequently implicated botanicals in registries of herb-induced liver injury, and taking it on an empty stomach appears to raise absorption and risk. On the weight-loss claim, the effect measured in trials is too small to matter to anyone.
Est-ce que green tea extract marche ?
Noté ici D : The better trials are negative, or the substance appears in the literature mainly for the harm it has caused. Weight loss, and any liver purpose whatsoever — this is one of the botanicals most likely to injure a liver, not support one.
Combien de green tea extract 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 :Brewed leaf tea (a food), and concentrated catechin extracts in capsules, often combined with caffeine in "fat burner" products. For extracts, the honest answer is that no safe long-term intake has been established.
Quels sont les effets indésirables de green tea extract ?
From tea, the effects of caffeine. From extracts, liver injury: dark urine, yellow eyes or skin, itching, unusual fatigue, pain under the right ribs. Stop immediately and seek medical care if those appear. Nausea and stomach upset are common, particularly fasted.
Est-ce que green tea extract interagit avec des médicaments ?
Oui — documenté pourLiver load, Iron, Anticoagulants, warfarin. Chacune est décrite sur cette page, avec un lien vers la référence côté médicament s’il en existe une.
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Garder toute la liste au même endroit
TempoLife consigne les compléments à côté de l’alimentation, du sommeil et de comment vous vous êtes vraiment senti — la réponse à « que prenez-vous ? » est un écran, pas une conjecture.