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Daphne mezereum
Toxic🐾Echter Seidelbast · (Daphne mezereum)
Daphne family (Thymelaeaceae)
Description
Before its first leaves even appear in earliest spring, the mezereon covers its bare branches with fragrant pink-purple flowers — a striking trait of this rare, legally protected shrub of Central European woodlands. Bright red stone fruit ripens through summer; historically it was mainly the bark and berries that were used, containing diterpene esters such as mezerein and daphnetoxin along with the coumarin glycoside daphnin. Folk medicine applied the bark externally for skin ailments and joint complaints — practices that, given the plant's extreme toxicity, are not advisable to follow today. Mezereon ranks among the most toxic native wild plants: just a few berries can be fatal to a child, and mere contact with bark sap causes painful skin blisters. The species is legally protected and must not be collected in any case.
External use only!
This plant must NOT be taken internally. Use only as compress, salve, or bath.
CONTRAINDICATED during pregnancy
Diterpene esters (mezerein, daphnetoxin) are potent PKC activators with tumour-promoter activity; any oral, dermal or homeopathic application below D6 is absolutely contraindicated in pregnancy. Placental transfer very likely.
CONTRAINDICATED during breastfeeding
Due to diterpene toxicity and co-carcinogenic action, any use during lactation is strictly contraindicated. Skin contact with plant sap during garden pruning should also be avoided.
CONTRAINDICATED for children
Children are extremely at risk — the bright-red berries appear particularly tempting to toddlers. As few as 4–5 berries can be fatal. Mezereon must not be planted in home gardens with small children; if present: remove berries consistently, cut before ripening. Berries swallowed: IMMEDIATELY call poison control.
Critical drug interactions with:
Topische Reizmittel und Rubefacientia (Capsaicin-Pflaster, Senfmehl, Cantharidin) · Phorbol-Ester-haltige Forschungssubstanzen (TPA / PMA) und PKC-Modulatoren · Schleimhaut-reizende Medikamente (NSAR, Bisphosphonate, Kaliumchlorid-Retardpräparate)
Historical topical use of mezereon bark plaster (Cortex Mezerei) as a vesicant (blistering agent) and counter-irritant in chronic rheumatism, sciatica and joint pain. Per Maud Grieve (1931), the moist bark was softened in hot vinegar-water and applied as a compress — within 24–48 hours redness and blisters formed as a derivative irritant therapy. Roughly 3 cm² of bark are sufficient to induce a severe skin lesion with percutaneous diterpene absorption. Strictly obsolete today due to the unpredictable systemic toxicity of mezerein and daphnetoxin.
Preparation & dosage
Historical application of a root-bark ointment to indolent ulcers, cold abscesses and poorly healing skin lesions — the ointment was meant to 'excite suppuration' by chemical irritation and accelerate healing. Maud Grieve and King's American Dispensatory document this use; the irritation rests on mezerein and daphnetoxin, which are massively absorbed through damaged skin. Strictly contraindicated today.
Preparation & dosage
Folk-medicinal application of softened bark to sore gums and toothache ('Kellerhals' — the German vernacular name refers to the burning in the throat on chewing). The chewing irritation was meant to produce salivation and a 'derivative' effect; in reality it causes severe mucosal corrosion with swelling of lips, tongue and pharynx. Considered obsolete since the 19th century.
Historical documentation only — do NOT use
These internal applications are historically documented. This plant is highly toxic — self-treatment can cause severe poisoning or death. For documentation only, explicitly NOT a recommendation.
Historical internal use of Decoctum Mezerei and mezereum fluid extract in the 18th and 19th centuries as an 'alterative' for syphilis (especially mercurio-syphilis after mercury treatments), scrofula and chronic skin diseases. Usual dosing per King's American Dispensatory (1898): decoction 1–3 fluid ounces, powder 10 grains, fluid extract 2–10 drops. Despite these very low doses, poisonings were regularly recorded. Strictly obsolete today — no therapeutic window, co-carcinogenic risk via mezerein as tumour promoter.
Preparation & dosage
Homeopathic use of Mezereum (mother tincture from fresh bark, proven by Samuel Hahnemann; typical dilution levels D6, D12, D30) for herpes zoster (shingles), post-herpetic neuralgia, itching eruptions with crust formation and bone pain. From D6 onwards preparations contain no pharmacologically active diterpene amount; licensed under medicinal-products law in Germany, Austria and Switzerland. Mother tincture and low potencies (D1–D3) remain highly toxic.
Preparation & dosage
Early modern folk medicine: use of the red berries as a drastic emetic and purgative — documented inter alia by Johannes Lonicer (16th century). A few berries were chewed to induce vomiting and diarrhoea; exceeding the arbitrary threshold caused mucosal corrosion and systemic poisoning. Lethal dose in children: 4–5 berries; in adults: 10–12 berries. Considered obsolete and dangerous since the late 19th century; purely ethnobotanical documentation.
⚠ External use only
HIGHLY TOXIC — ALL PARTS, ESPECIALLY BARK, SEEDS AND BERRIES. Daphne mezereum is one of the most dangerous native wild plants in Central Europe. Lethal oral dose: 4–5 red berries in children, 10–12 in adults; about 30 g of bark kills a horse. As little as 3 cm² of moist bark is enough to produce a severe skin blister with percutaneous absorption. The main toxins are the diterpene esters mezerein and daphnetoxin (PKC activators, tumour promoters) and the coumarin glycoside daphnin. Symptoms: burning and swelling of mouth, lips and throat, dysphagia, hypersalivation, nausea, vomiting, bloody diarrhoea, abdominal cramps, fever, tachycardia; in severe poisoning, kidney damage, CNS paralysis and circulatory collapse. Contact with berries and bark sap causes skin redness, blisters and dermatitis. Mezerein acts as a tumour promoter (second-stage carcinogenesis) in animal experiments. In suspected poisoning: IMMEDIATELY call emergency services and poison control. No specific antidote — symptomatic therapy (gastric lavage within the first hours, activated charcoal, fluid replacement). Protected in Germany and Austria under the Federal Species Protection Ordinance; protected in the United Kingdom since 1975.
Diterpene esters (mezerein, daphnetoxin) are potent PKC activators with tumour-promoter activity; any oral, dermal or homeopathic application below D6 is absolutely contraindicated in pregnancy. Placental transfer very likely.
Due to diterpene toxicity and co-carcinogenic action, any use during lactation is strictly contraindicated. Skin contact with plant sap during garden pruning should also be avoided.
Children are extremely at risk — the bright-red berries appear particularly tempting to toddlers. As few as 4–5 berries can be fatal. Mezereon must not be planted in home gardens with small children; if present: remove berries consistently, cut before ripening. Berries swallowed: IMMEDIATELY call poison control.
Drug interactions
Topische Reizmittel und Rubefacientia (Capsaicin-Pflaster, Senfmehl, Cantharidin)
Additive skin irritation and blistering; concurrent use increases the risk of extensive corrosive lesions with substantial percutaneous absorption of the diterpene esters.
Phorbol-Ester-haltige Forschungssubstanzen (TPA / PMA) und PKC-Modulatoren
Mezerein and daphnetoxin — like TPA — persistently activate protein kinase C. Combination with other PKC activators causes massive overstimulation of PKC-dependent signalling pathways; in tumour models, synergistic tumour-promoter activity. Clinically irrelevant but relevant for laboratory exposure and research.
Antikoagulanzien (Phenprocoumon, Warfarin, DOAKs)
Daphnin and daphnetin are hydroxycoumarins; although their pharmacological coumarin effect is weak, additive coumarin effects and increased bleeding risk should be considered with internal exposure. Theoretical risk, not systematically studied clinically.
Schleimhaut-reizende Medikamente (NSAR, Bisphosphonate, Kaliumchlorid-Retardpräparate)
Mezerein causes direct gastrointestinal mucosal corrosion; concurrent administration of NSAID-related mucosa-damaging substances substantially increases the risk of ulceration and bleeding.
Contraindications
- Any self-administration of plant material (fresh plant, dried bark, berries, tea, homemade tincture, ointment) — absolutely contraindicated due to absent therapeutic window
- Skin lesions, open wounds, eczema — drastically increased percutaneous absorption of mezerein and daphnetoxin
- Conditions with mucosal lesions (gastritis, ulcer, colitis) — mezerein causes direct mucosal corrosion
- Renal and hepatic insufficiency — delayed elimination of diterpene esters
- Pre-existing or concurrent oncological conditions — mezerein is an established tumour promoter (PKC activation)
- Pregnancy, lactation, children and adolescents (see above)
Harvested part: bark and berries
- Time of day:
- In autumn after berry drop, on dry days — historical bark-drug harvest for pharmaceutical processing. NO lay harvest.
- Drying:
- Dry bark in thin strips on drying racks at max. 40 °C in shade. IMPERMEABLE PROTECTIVE GLOVES MANDATORY — fresh bark sap produces skin blisters with percutaneous diterpene absorption after 24–48 h. Avoid aerosol exposure when cutting (wear respirator). Dried bark retains toxicity for years and must be stored in containers clearly marked TOXIC — out of reach of children and pets.
- Time of day:
- Ripe berries from high summer (July–September). Harvest only for botanical or pharmaceutical purposes; in the garden, cut berries consistently before ripening when children or pets have access.
- Drying:
- Do not dry for domestic use due to mezerein and daphnin content. Pharmaceutical processing under protective equipment and in closed facilities.
- MezereinOtherContent: ca. 0.1 %
Main diterpene ester (daphnane-type) of seeds and bark of Daphne mezereum; C38H38O10, MW 654.7 g/mol. Like the phorbol-ester analogue TPA, it persistently activates protein kinase C (a DAG mimetic, but not degradable) — causing overstimulation of PKC signalling and tumour-promoter activity at the second stage of carcinogenesis. Causes severe mucosal corrosion, vomiting, diarrhoea and skin blistering. In animal experiments paradoxical dose-response: low doses act pro-tumorally, high doses can terminally differentiate leukaemia cells.
- DaphnetoxinOtherContent: nicht quantifiziert
Diterpene ester of the daphnane series, predominantly in the bark. Co-carcinogen with mezerein, PKC activator. Responsible for the strong vesicant (blistering) action of fresh bark within 24–48 hours on skin contact. Rapidly absorbed through damaged skin and can cause systemic mucosal lesions, tachycardia and circulatory collapse.
- DaphninGlycosideContent: nicht quantifiziert
Coumarin glycoside (C15H16O9; hydroxycoumarin glycoside of daphnetin); enriched in berries and twigs. Contributes to GI irritation, CNS involvement (confusion, miosis, shallow breathing, seizures) and percutaneous skin irritation. Pharmacologically subordinate to the highly active daphnetoxin.
- Daphnetin (7,8-Dihydroxycumarin)OtherContent: Spuren
Aglycone of daphnin; hydroxycoumarin with weak antioxidant and, at higher concentrations, anticoagulant action. Present in small quantities in Daphne mezereum material. In experimental studies daphnetin is used as a research object for anti-inflammatory and antimalarial effects, but is not obtained from mezereon.
- Umbelliferon (7-Hydroxycumarin)OtherContent: Spuren
Companion hydroxycoumarin in the plant parts; contributes to the typical UV fluorescence of aqueous bark extracts. Pharmacologically subordinate to the diterpene esters.
- Fettes SamenölOtherContent: bis 31 %
The seeds contain up to 31 % fatty oil, but this is not usable due to the highly toxic diterpene esters also present. No technical or culinary use.
- Sitosterol und TriterpeneOtherContent: nicht quantifiziert
Companion phytosterols and triterpenes in bark and root bark; pharmacologically irrelevant compared to the diterpene esters but routinely detected in phytochemical analyses.
- Akrides Harz ('Mezereum-Harz')OtherContent: nicht quantifiziert
Described in King's American Dispensatory (1898) as 'acrid resin, soluble in alcohol and ether, insoluble in water' — today identified as a diterpene ester mixture (mezerein, daphnetoxin, related compounds). Carries the entire vesicant and systemic toxicity of the drug.
- [8]MonographCliniTox Giftpflanzen — Daphne mezereum L.: sehr stark giftig +++ (Institut für Veterinärpharmakologie und -toxikologie, Universität Zürich)(accessed: 2026-08-10)
- [5]BookPlants For A Future — Daphne mezereum(accessed: 2026-05-26)
- [6]BookMaud Grieve: A Modern Herbal — Mezereon (botanical.com, 1931)(accessed: 2026-05-26)
- [7]BookMezereum (U. S. P.) — King's American Dispensatory, 1898 (Henriette's Herbal)(accessed: 2026-05-26)
- [1]WikipediaEchter Seidelbast — Wikipedia (DE)(accessed: 2026-05-26)
- [2]WikipediaDaphne mezereum — Wikipedia (EN)(accessed: 2026-05-26)
- [3]WikipediaMezerein — Wikipedia (EN)(accessed: 2026-05-26)
- [4]WikipediaDaphnin — Wikipedia (EN)(accessed: 2026-05-26)