Body & Beauty / Compounds / α-Thujone

α-Thujone on your skin: a safety profile

Moderate risk

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Direct skin contact with α-thujone-bearing essential oils (Thuja + Artemisia + Salvia) produces moderate dermal absorption + GABA-A-mediated systemic uptake at concentrate strength. IFRA 51st Amendment + EU Cosmetics + FDA 21 CFR 172.510 all ground the framework. Aromatherapy + fragrance-manufacturing cohort + traditional-medicine compounding-pharmacist cohort apply.

What is α-thujone?

The IUPAC name is (1S,4R,5R)-4-methyl-1-propan-2-ylbicyclo[3.1.0]hexan-3-one.

Also known as: (1S,4R,5R)-4-methyl-1-propan-2-ylbicyclo[3.1.0]hexan-3-one, alpha-Thujone, THUJONE, (-)-alpha-thujone.

IUPAC name
(1S,4R,5R)-4-methyl-1-propan-2-ylbicyclo[3.1.0]hexan-3-one
CAS number
546-80-5
Molecular formula
C10H16O
Molecular weight
152.23 g/mol
SMILES
CC1C2CC2(CC1=O)C(C)C
PubChem CID
261491

Risk for people

Moderate risk

Direct skin contact with α-thujone-bearing essential oils (Thuja + Artemisia + Salvia) produces moderate dermal absorption + GABA-A-mediated systemic uptake at concentrate strength. IFRA 51st Amendment + EU Cosmetics + FDA 21 CFR 172.510 all ground the framework. Aromatherapy + fragrance-manufacturing cohort + traditional-medicine compounding-pharmacist cohort apply.

Regulatory consensus

1 regulatory bodyhas classified α-Thujone.

AgencyYearClassificationNotes
EDC Assessment—Suspected endocrine disruptor

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter α-thujone

  • Food — absinthe, sage, thuja (cedar leaf)
  • Personal Care — essential oils containing thujone (sage, wormwood, tansy)
  • Fragrance — perfume, cologne, scented personal care products, household fragrance products, candles
    Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to α-Thujone:

  • Avoidance (no chemical substitute)
    Trade-offs: Direct chemical substitution requires verification that the replacement does not introduce new hazards (regrettable substitution). Conduct full hazard assessment of proposed alternative before adoption.
    Relative cost: 1.2-2×

Frequently asked questions

Is α-thujone safe for you?

Direct skin contact with α-thujone-bearing essential oils (Thuja + Artemisia + Salvia) produces moderate dermal absorption + GABA-A-mediated systemic uptake at concentrate strength. IFRA 51st Amendment + EU Cosmetics + FDA 21 CFR 172.510 all ground the framework. Aromatherapy + fragrance-manufacturing cohort + traditional-medicine compounding-pharmacist cohort apply.

What products contain α-thujone?

α-Thujone appears in: absinthe (Food); sage (Food); essential oils containing thujone (sage, wormwood, tansy) (Personal care); perfume (Fragrance); cologne (Fragrance).

See α-Thujone in the body app

Look up products containing α-thujone, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (6)
  1. PubChem Compound Database (2026) — database
  2. FDA 21 CFR 172.510 — Thujone permitted in food only when present in plant materials (Artemisia + Salvia + Salvia officinalis at <10 ppm thujone-equivalents in finished food); banned as added pure substance (2018) — regulatory
  3. IFRA Standard 51st Amendment — α + β-Thujone in fragrance products (GABA-A antagonist convulsant restriction; finished-product limits per product category) (2024) — regulatory
  4. EFSA Scientific Opinion on α + β-Thujone (FGE.31 — Maximum permitted levels in alcoholic beverages 35 mg/L spirits ≤25% alcohol + 10 mg/L bitters / 5 mg/L liqueurs and dietary food) (2016) — regulatory
  5. EU Regulation (EC) No 1334/2008 on flavourings — α + β-Thujone maximum permitted concentrations in absinthe + bitter alcoholic beverages (2008) — regulatory
  6. Höld KM, Sirisoma NS, Ikeda T, Narahashi T, Casida JE — α-Thujone (the active component of absinthe): γ-aminobutyric acid type A receptor modulation and metabolic detoxification (mechanism + LD50 + chronic-cohort framework, PNAS) (2000) — study

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for medical, legal, or regulatory advice. Why we built ALETHEIA →