alpha-Thujone

alpha-Thujone at a Glance

alpha-Thujone is a small bicyclic monoterpene ketone, and the best-known neurotoxin in the western herbal cabinet. It is the dominant volatile of western red cedar foliage, a major component of common sage and wormwood oils, and the molecule that gave absinthe its dangerous reputation. Its pharmacology is now well settled: it blocks the GABA-A receptor’s chloride channel, behaving like the classical convulsant picrotoxinin, and at sufficient dose it causes seizures ^{1Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →}.

It is also rapidly destroyed. Liver cytochrome-P450 enzymes hydroxylate it within minutes to 7-hydroxy-alpha-thujone and several other metabolites, all of them less toxic than the parent — so the poisoning is fast in onset and short in duration, and blocking those enzymes makes thujone considerably more dangerous ^{1,2Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →}. The metabolism runs mainly through CYP2A6, then CYP3A4 ^{3Reference 3Pelkonen O et al. · 2013ReviewThujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — reviewView study →}.

The most useful correction on this molecule is historical. Chemical analysis of absinthes made to nineteenth-century recipes, and of surviving pre-ban bottles, found thujone at 0–4.3 mg/L — not the 260 mg/L the period literature claimed, and comfortably inside the modern legal limit ^{16Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}. Whatever “absinthism” was, it was not thujone poisoning; the alcohol was the obvious candidate all along. The real hazard is elsewhere: concentrated essential oils of wormwood, sage, tansy and thuja, which have caused seizures in people, including children ^{7,8,9Reference 7Burkhard PR et al. · 1999Case reportPlant-induced seizures: reappearance of an old problem — case reportView study →Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →Reference 9Weisbord SD et al. · 1997Case reportPoison on line—acute renal failure caused by oil of wormwood purchased through the Internet — case reportView study →}.

The GABA-A Mechanism

The 2000 study that settled thujone’s pharmacology built its case from four directions at once. Poisoning signs in mice matched those of picrotoxinin, the classical chloride-channel blocker, and were relieved by diazepam and phenobarbital; a Drosophila strain specifically resistant to chloride-channel blockers was also resistant to alpha-thujone; alpha-thujone competitively inhibited the binding of the channel-blocker ligand EBOB to mouse brain membranes; and, most directly, it suppressed GABA-induced currents in rat dorsal-root-ganglion neurons, with complete recovery after washout ^{1Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →}.

That last detail matters. Thujone is a reversible blocker of the GABA-gated chloride channel — it does not damage the receptor, it occupies it. Combined with fast metabolic clearance, this explains the shape of thujone toxicity: an acute, dose-dependent excitatory syndrome that resolves rather than a cumulative neurodegeneration. The convulsant effect is the direct consequence of removing inhibitory GABA tone from the central nervous system.

It is not a sedative, and it is not psychedelic. The nineteenth-century idea that thujone produces hallucinations has no mechanistic basis; disinhibition at high dose looks like agitation and seizures, not visions.

Alpha & Beta: The Two Diastereomers

Thujone occurs in plants as two diastereomers that differ only in the orientation of a methyl group — alpha-thujone and beta-thujone — and they nearly always occur together, which is why analyses and regulations usually report “thujone (α+β)”. The pair is close enough in behaviour that treating them separately is often artificial, but they are not identical.

Alpha-thujone is the more potent GABA-A blocker and the better-studied of the two ^{1Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →}. Direct comparison came from an unusual model: injected into the brains of three-day-old chicks, 78 nmol of either diastereomer produced the same anxiogenic-like behaviour — longer latency to move, less locomotion in an open field — and higher doses of both were convulsant. But only alpha-thujone reversed the stress-induced recruitment of flunitrazepam-sensitive GABA-A receptors, leading the authors to suggest beta-thujone reaches similar behavioural endpoints partly through other systems, possibly serotonergic ^{4Reference 4Rivera EM et al. · 2014AnimalCentral α- and β-thujone: similar anxiogenic-like effects and differential modulation on GABAA receptors in neonatal chicks — animal in vivoView study →}.

They also differ metabolically. Both are detoxified by P450 hydroxylation, but the preferred position on the molecule depends on which diastereomer and which species is doing the metabolising: 2-position hydroxylation happens only in mice, 4-hydroxy-alpha-thujone is the major urinary metabolite of both diastereomers in rats, and 7-position hydroxylation is always a major route in vitro but usually a minor urinary product ^{2Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →}. For practical purposes — a herb page, a safety limit, an oil analysis — the two are handled as one substance, and the toxicology below is for the mixture unless stated.

The Absinthe Correction

Absinthe was banned across Europe and the United States in the early twentieth century on the strength of “absinthism”, a syndrome of hallucinations, sleeplessness and convulsions attributed to wormwood’s thujone. The chemistry does not support the charge.

Researchers produced absinthes from authentic nineteenth-century recipes at historic wormwood loadings (6 kg per 100 L of spirit), and analysed them alongside a vintage 1930 Pernod from Tarragona and two traditional Val-de-Travers absinthes. Every sample fell below the modern European maximum of 35 mg/L. The historic-recipe absinthes averaged 1.3 mg/L (range 0–4.3), the vintage bottle held 1.8 mg/L, and the Swiss products 1.7 and 9.4 mg/L. The 260 mg/L figure quoted in the nineteenth-century literature could not be reproduced ^{16Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}. A follow-up ruled out the obvious objection — that thujone had simply decayed over eighty years — by showing that absinthe stored in traditional green glass keeps its thujone indefinitely, and that only clear-glass storage under ultraviolet light caused any loss (18% of beta-thujone), with the preserved colour of the pre-ban bottles proving they had not been light-exposed ^{15Reference 15Lachenmeier DW et al. · 2009Long-term stability of thujone, fenchone, and pinocamphone in vintage preban absinthe — analyticalView study →}.

If thujone was not the cause, what was? The reviews point at the obvious: absinthe was 45–74% alcohol, drunk heavily and daily, sometimes adulterated with genuinely toxic colourings ^{14Reference 14Lachenmeier DW et al. · 2006ReviewAbsinthe—a review — reviewView study →}. “Absinthism” is largely chronic alcoholism with a botanical alibi.

One controlled experiment does show a thujone effect at the top of the legal range. Twenty-five volunteers drank three preparations with identical alcohol content and different thujone levels: the high-thujone drink impaired attention — more false alarms, slower reactions, and neglect of the peripheral visual field — and temporarily counteracted alcohol’s anxiolytic effect, consistent with GABA-A antagonism opposing GABA-A potentiation ^{5Reference 5Dettling A et al. · 2004RCTAbsinthe: attention performance and mood under the influence of thujone — randomised controlled trialView study →}. It is a real pharmacological signal, in the direction the mechanism predicts, and nothing like hallucinations.

What It's Used For

Thujone has no therapeutic application. The literature is a toxicology literature, with the antimicrobial activity of thujone-rich oils as the one place the molecule does something a person might want.

Evidence by IndicationStrength of support · Beta

01Neurotoxicity (GABA-A Antagonism)Promising68%Four independent lines of mechanism + rodent 2-year gavage + human case reports ^{1,6,7,8Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →Reference 6National Toxicology Program · 2011AnimalToxicology and carcinogenesis studies of alpha,beta-thujone (CAS NoView study →Reference 7Burkhard PR et al. · 1999Case reportPlant-induced seizures: reappearance of an old problem — case reportView study →Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →}

02Antimicrobial (as an Oil Constituent)Shaky26%Isolated α/β mixture vs 6 bacteria and 3 fungi; whole-oil comparisons ^{13Reference 13Tsiri D et al. · 2009In vitroChemosystematic value of the essential oil composition of Thuja species cultivated in Poland-antimicrobial activity — in vitroView study →}

03Cognitive & Mood Effects (Absinthe)Shaky25%One 25-subject controlled crossover at legal-limit thujone ^{5Reference 5Dettling A et al. · 2004RCTAbsinthe: attention performance and mood under the influence of thujone — randomised controlled trialView study →}

04CarcinogenicityShaky20%NTP two-year gavage: preputial-gland tumours in male rats only ^{6Reference 6National Toxicology Program · 2011AnimalToxicology and carcinogenesis studies of alpha,beta-thujone (CAS NoView study →}

Mechanisms

It all follows from one fact and its counterweight: thujone removes GABA-A inhibition, and the liver removes thujone.

Pharmacokinetics

Thujone is metabolised fast, and that is the single most important pharmacokinetic fact about it. In mouse liver microsomes with NADPH it is consumed quickly, giving 7-hydroxy-alpha-thujone as the major product plus 4-hydroxy-alpha- and -beta-thujone, two further hydroxythujones and 7,8-dehydro-alpha-thujone; several of these appear in the brains of treated mice, and the 7-hydroxy metabolite reaches much higher brain concentrations than the parent while being markedly less toxic and weaker at the receptor ^{1Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →}. Human recombinant enzyme work identifies CYP2A6 as the principal catalyst, with CYP3A4 second and CYP2B6 minor ^{3Reference 3Pelkonen O et al. · 2013ReviewThujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — reviewView study →}.

That these oxidations are detoxification rather than activation is shown two ways: three P450 inhibitors blocked thujone metabolism and strongly synergised its toxicity in Drosophila, and all six metabolites assayed were weaker than the parent both at the GABA-A receptor and as toxicants ^{2Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →}. Metabolite patterns differ substantially between mouse, rat and human preparations, and between in-vitro microsomes and in-vivo urine, so cross-species extrapolation of thujone toxicity is unusually shaky ^{2Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →}. No human pharmacokinetic study exists — bioavailability, half-life and the dose-concentration-effect relationship in people are all unmeasured, which regulatory reviewers name as the main gap under any intake limit ^{3Reference 3Pelkonen O et al. · 2013ReviewThujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — reviewView study →}.

The interaction implication follows directly. Anything that inhibits CYP2A6 or CYP3A4 should be expected to raise thujone exposure, and the Drosophila synergy experiment is the proof of principle. This has never been studied clinically.

Clinical Trials

No trial has given thujone as a treatment for anything. The only controlled human administration is the absinthe attention study, in which thujone was the variable rather than the therapy ^{5Reference 5Dettling A et al. · 2004RCTAbsinthe: attention performance and mood under the influence of thujone — randomised controlled trialView study →}; everything else in people is case reports of poisoning ^{7,8,9Reference 7Burkhard PR et al. · 1999Case reportPlant-induced seizures: reappearance of an old problem — case reportView study →Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →Reference 9Weisbord SD et al. · 1997Case reportPoison on line—acute renal failure caused by oil of wormwood purchased through the Internet — case reportView study →} and analytical surveys of dietary exposure ^{10,16Reference 10Walch SG et al. · 2011Determination of the biologically active flavour substances thujone and camphor in foods and medicines containing sage (Salvia officinalis L.) — analyticalView study →Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}.

Last checked: September 2026.

Isolate vs. Plant Studies

The mechanism is isolate work — purified alpha-thujone in receptor binding, patch clamp, microsomes and gavage studies ^{1,2,6Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →Reference 6National Toxicology Program · 2011AnimalToxicology and carcinogenesis studies of alpha,beta-thujone (CAS NoView study →} — and it transfers cleanly to the plants, because thujone in a herb behaves as thujone. What does not transfer is dose. The rodent seizure doses (25–50 mg/kg) are essential-oil-scale exposures, and the herbal reality splits sharply by preparation:

• Essential oil — the isolate-equivalent exposure, and the one that has caused human seizures and renal failure ^{7,8,9Reference 7Burkhard PR et al. · 1999Case reportPlant-induced seizures: reappearance of an old problem — case reportView study →Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →Reference 9Weisbord SD et al. · 1997Case reportPoison on line—acute renal failure caused by oil of wormwood purchased through the Internet — case reportView study →}.
• Aqueous infusion — a fraction of it. Sage tea infusions measured 4.4 mg/L thujone in food-grade teas and 11.3 mg/L in medicinal teas, with water recovering only about 30% of what 60% ethanol extracts; the authors concluded three to six cups a day stay below toxicological thresholds ^{10Reference 10Walch SG et al. · 2011Determination of the biologically active flavour substances thujone and camphor in foods and medicines containing sage (Salvia officinalis L.) — analyticalView study →}.
• Spirit — regulated. The European maximum for bitter spirits is 35 mg/L, and historic and vintage absinthes sat far below it ^{14,16Reference 14Lachenmeier DW et al. · 2006ReviewAbsinthe—a review — reviewView study →Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}.

The other transfer failure is chemotype. Thujone content is a property of a population, not a species: wormwood exists as a sabinyl-acetate chemotype and a thujone chemotype, with eleven Polish populations differing widely across 41 oil constituents ^{18Reference 18Kosakowska O et al. · 2025Intraspecific Variability of Wormwood (Artemisia absinthium L.) Occurring in Poland in Respect of Developmental and Chemical Traits — analyticalView study →}, sage oil resolves into five chemotypes including a beta-thujone-rich one ^{11Reference 11Craft JD et al. · 2017The Chemotaxonomy of Common Sage (Salvia officinalis) Based on the Volatile Constituents — analyticalView study →}, and thujone-free sage relatives are used deliberately in cognition research. A safety statement about “sage” or “wormwood” that ignores chemotype is guesswork.

Prevalence in Nature

Thujone is a Cupressaceae and Asteraceae–Lamiaceae molecule, concentrated in aromatic foliage.

Its richest source is western red cedar (Thuja plicata), whose foliar oil is typically 50–85% alpha-thujone ^{12Reference 12Lis A et al. · 2019Chemical composition of the essential oils from twigs, leaves and cones of Thuja plicata and its cultivar varieties — analyticalView study →} — the reason cedar-leaf oil is a disinfectant rather than a medicine. Across cultivated Thuja species the total ketone content (alpha- and beta-thujone with fenchone) runs 54–69% of the oil, with sabinene and the diterpenes beyerene and rimuene alongside ^{13Reference 13Tsiri D et al. · 2009In vitroChemosystematic value of the essential oil composition of Thuja species cultivated in Poland-antimicrobial activity — in vitroView study →}; chiral analysis of Idaho T. plicata confirms that the Cupressaceae favour the (+)-enantiomers of their monoterpenoids, unlike the neighbouring Pinaceae ^{17Reference 17Swor K et al. · 2023Gymnosperms of Idaho: Chemical Compositions and Enantiomeric Distributions of Essential Oils of Abies lasiocarpa, Picea engelmannii, Pinus contorta, Pseudotsuga menziesii, and Thuja plicata — analyticalView study →}.

In common sage (Salvia officinalis) alpha-thujone is the leading oxygenated monoterpenoid at 17.2–27.4% of leaf oil, ahead of 1,8-cineole and camphor in the commonest chemotype, with beta-thujone a smaller component and a distinct beta-thujone-rich chemotype on record ^{11Reference 11Craft JD et al. · 2017The Chemotaxonomy of Common Sage (Salvia officinalis) Based on the Volatile Constituents — analyticalView study →}. In wormwood (Artemisia absinthium) thujone runs to roughly 10–36% of the oil in the thujone chemotype ^{18,19Reference 18Kosakowska O et al. · 2025Intraspecific Variability of Wormwood (Artemisia absinthium L.) Occurring in Poland in Respect of Developmental and Chemical Traits — analyticalView study →Reference 19Orav et al. · 2006Composition of the essential oil of Artemisia absinthium L. of different geographical origin} — but the plant’s essential oil, at 0.75–1.69 g per 100 g dry weight, is often dominated instead by sabinyl acetate, and several populations are effectively thujone-free ^{18Reference 18Kosakowska O et al. · 2025Intraspecific Variability of Wormwood (Artemisia absinthium L.) Occurring in Poland in Respect of Developmental and Chemical Traits — analyticalView study →}. Mugwort, yarrow, feverfew, tansy and several sagebrush species carry it in smaller and highly variable amounts.

Discovery & Synthesis

Thujone has been known since the nineteenth century as the characteristic ketone of thuja and wormwood oils, and it takes its name from Thuja. Its notoriety long preceded its pharmacology: it was blamed for absinthism from the 1860s, banned by proxy when absinthe was prohibited, and only in 2000 was its mechanism actually established as GABA-A chloride-channel blockade ^{1Reference 1Höld KM et al. · 2000In vitroAlpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivoView study →}, with the detoxification pathway mapped the following year ^{2Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →}. The 2006 analytical work that cleared it of causing absinthism came four decades after the drink’s rehabilitation began ^{16Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}.

There is no commercial synthesis of interest; thujone is obtained as a constituent of distilled essential oils and as an analytical standard, and the industrial effort has gone the other way — into removing it, through chemotype selection and distillation practice, so that sage and wormwood products meet food limits ^{14Reference 14Lachenmeier DW et al. · 2006ReviewAbsinthe—a review — reviewView study →}.

Toxicity & Safety

Thujone carries a toxic flag, and it is one of the few plant constituents where that is not a precaution but a description. It is a convulsant with documented human poisonings.

The Exposure That Matters Is Essential Oil

Every serious human case involves concentrated oil, not herb. Three patients — two adults and a child — had generalised tonic-clonic seizures or status epilepticus after taking monoterpene-ketone-rich plant oils therapeutically; the accompanying review names eleven convulsant essential oils including sage, thuja, tansy, savin and wormwood, attributing the effect to camphor, thujone, pinocamphone, pulegone, cineole, sabinyl acetate and fenchone ^{7Reference 7Burkhard PR et al. · 1999Case reportPlant-induced seizures: reappearance of an old problem — case reportView study →}. A newborn and a toddler had seizures after accidental sage-oil exposure, the newborn repeatedly ^{8Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →}. A man developed acute renal failure after drinking oil of wormwood bought over the internet ^{9Reference 9Weisbord SD et al. · 1997Case reportPoison on line—acute renal failure caused by oil of wormwood purchased through the Internet — case reportView study →}. Thujone-containing essential oils should not be taken internally at all, and this applies to wormwood, sage, tansy, thuja and cedar-leaf oils alike.

Doses and Limits

Regulatory assessment places a tolerable daily intake at roughly 3–7 mg/day from herbal preparations and diet combined, based on neurotoxicity rather than the equivocal cancer finding, and explicitly flags the missing human dose-response data as the weakness in that estimate ^{3Reference 3Pelkonen O et al. · 2013ReviewThujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — reviewView study →}. The European maximum for bitter spirits is 35 mg/L ^{14,16Reference 14Lachenmeier DW et al. · 2006ReviewAbsinthe—a review — reviewView study →Reference 16Lachenmeier DW et al. · 2006Thujone—cause of absinthism? — analyticalView study →}. Sage tea measurements put a cup at a few milligrams per litre, supporting three to six cups daily as an ordinary intake ^{10Reference 10Walch SG et al. · 2011Determination of the biologically active flavour substances thujone and camphor in foods and medicines containing sage (Salvia officinalis L.) — analyticalView study →}, which is a more moderate conclusion than the blanket advice to avoid sage tea.

Who Should Avoid It

People with epilepsy or any seizure history should avoid thujone-rich preparations, as should anyone taking a drug that lowers the seizure threshold; thujone opposes GABA-A signalling, which is the same target benzodiazepines and several anticonvulsants work through in the opposite direction. Because clearance depends on CYP2A6 and CYP3A4, inhibitors of those enzymes would be expected to increase exposure — demonstrated in insects, untested in people ^{2,3Reference 2Höld KM et al. · 2001In vitroDetoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivoView study →Reference 3Pelkonen O et al. · 2013ReviewThujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — reviewView study →}. Children are disproportionately represented in the seizure reports ^{8Reference 8Halicioglu O et al. · 2011Case reportToxicity of Salvia officinalis in a newborn and a child: an alarming report — case reportView study →}. Prolonged high-dose use of wormwood or sage preparations is not appropriate, and thujone-containing herbs are traditionally avoided in pregnancy; that decision belongs on the herb page, where the preparation and dose are known.

Safety at a Glance

☠️ ToxicEssential-oil toxicity

• A convulsant. GABA-A chloride-channel blockade causes dose-dependent seizures; rodents seized at 25 mg/kg and died at 50 mg/kg.
• Never take thujone-rich essential oils internally. Documented human seizures and one case of acute renal failure, including in children.
• Avoid with epilepsy or seizure-lowering drugs, and be aware that CYP2A6/CYP3A4 inhibitors would be expected to raise exposure.
• Chemotype decides the dose. Wormwood and sage vary from thujone-free to thujone-dominant; a species name is not a safety statement.
• Culinary and tea-level exposure is modest. Sage infusions run at a few mg/L, and three to six cups a day sit under the toxicological threshold.
• Absinthe was not the problem. Historic and vintage absinthes carried 0–4.3 mg/L, far below the 35 mg/L limit; absinthism tracks the alcohol.

Dosage

There is no therapeutic dose of thujone, and no preparation should be taken to obtain it. The figures below are exposure limits and measured contents, not recommendations.

References

1. Höld KM, Sirisoma NS, Ikeda T, et al. (2000). Alpha-thujone (the active component of absinthe): gamma-aminobutyric acid type A receptor modulation and metabolic detoxification — in vitro and animal in vivo. Proc Natl Acad Sci U S A. https://pubmed.ncbi.nlm.nih.gov/10725394/
2. Höld KM, Sirisoma NS, Casida JE (2001). Detoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo — animal in vivo. Chem Res Toxicol. https://pubmed.ncbi.nlm.nih.gov/11368559/
3. Pelkonen O, Abass K, Wiesner J (2013). Thujone and thujone-containing herbal medicinal and botanical products: toxicological assessment — review. Regul Toxicol Pharmacol. https://pubmed.ncbi.nlm.nih.gov/23201408/
4. Rivera EM, Cid MP, Zunino P, et al. (2014). Central α- and β-thujone: similar anxiogenic-like effects and differential modulation on GABAA receptors in neonatal chicks — animal in vivo. Brain Res. https://pubmed.ncbi.nlm.nih.gov/24486357/
5. Dettling A, Grass H, Schuff A, et al. (2004). Absinthe: attention performance and mood under the influence of thujone — randomised controlled trial. J Stud Alcohol. https://pubmed.ncbi.nlm.nih.gov/15536765/
6. National Toxicology Program (2011). Toxicology and carcinogenesis studies of alpha,beta-thujone (CAS No. 76231-76-0) in F344/N rats and B6C3F1 mice (gavage studies) — animal in vivo. Natl Toxicol Program Tech Rep Ser. https://pubmed.ncbi.nlm.nih.gov/22127327/
7. Burkhard PR, Burkhardt K, Haenggeli CA, et al. (1999). Plant-induced seizures: reappearance of an old problem — case report. J Neurol. https://pubmed.ncbi.nlm.nih.gov/10460442/
8. Halicioglu O, Astarcioglu G, Yaprak I, et al. (2011). Toxicity of Salvia officinalis in a newborn and a child: an alarming report — case report. Pediatr Neurol. https://pubmed.ncbi.nlm.nih.gov/21907890/
9. Weisbord SD, Soule JB, Kimmel PL (1997). Poison on line—acute renal failure caused by oil of wormwood purchased through the Internet — case report. N Engl J Med. https://pubmed.ncbi.nlm.nih.gov/9297113/
10. Walch SG, Kuballa T, Stühlinger W, et al. (2011). Determination of the biologically active flavour substances thujone and camphor in foods and medicines containing sage (Salvia officinalis L.) — analytical. Chem Cent J. https://pubmed.ncbi.nlm.nih.gov/21777420/
11. Craft JD, Satyal P, Setzer WN (2017). The Chemotaxonomy of Common Sage (Salvia officinalis) Based on the Volatile Constituents — analytical. Medicines (Basel). https://pubmed.ncbi.nlm.nih.gov/28930262/
12. Lis A, Swaczyna A, Krajewska A, Mellor K (2019). Chemical composition of the essential oils from twigs, leaves and cones of Thuja plicata and its cultivar varieties — analytical. Natural Product Communications. https://doi.org/10.1177/1934578X19862904
13. Tsiri D, Graikou K, Pobłocka-Olech L, et al. (2009). Chemosystematic value of the essential oil composition of Thuja species cultivated in Poland-antimicrobial activity — in vitro. Molecules. https://pubmed.ncbi.nlm.nih.gov/19935470/
14. Lachenmeier DW, Walch SG, Padosch SA, et al. (2006). Absinthe—a review — review. Crit Rev Food Sci Nutr. https://pubmed.ncbi.nlm.nih.gov/16891209/
15. Lachenmeier DW, Nathan-Maister D, Breaux TA, et al. (2009). Long-term stability of thujone, fenchone, and pinocamphone in vintage preban absinthe — analytical. J Agric Food Chem. https://pubmed.ncbi.nlm.nih.gov/19256492/
16. Lachenmeier DW, Emmert J, Kuballa T, et al. (2006). Thujone—cause of absinthism? — analytical. Forensic Sci Int. https://pubmed.ncbi.nlm.nih.gov/15896935/
17. Swor K, Satyal P, Poudel A, et al. (2023). Gymnosperms of Idaho: Chemical Compositions and Enantiomeric Distributions of Essential Oils of Abies lasiocarpa, Picea engelmannii, Pinus contorta, Pseudotsuga menziesii, and Thuja plicata — analytical. Molecules. https://pubmed.ncbi.nlm.nih.gov/36985451/
18. Kosakowska O, Węglarz Z, Żuchowska A, et al. (2025). Intraspecific Variability of Wormwood (Artemisia absinthium L.) Occurring in Poland in Respect of Developmental and Chemical Traits — analytical. Molecules. https://pubmed.ncbi.nlm.nih.gov/40733181/
19. Orav, A., Raal, A., Arak, E., Muurisepp, M., & Kailas, T. (2006). Composition of the essential oil of Artemisia absinthium L. of different geographical origin. Proceedings of the Estonian Academy of Sciences Chemistry, 55(3), 155.

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