Compound Monograph

Beta-thujone

Beta-thujone is a monoterpene ketone from wormwood, sage and thuja, notable as the constituent of absinthe historically blamed for its effects.

Classification

Beta-thujone is a monoterpene (ketone), part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.

Where Does It Come From? (3)

Beta-thujone is a naturally occurring monoterpene (ketone), found in Wormwood, Sage and Thuja / white cedar. It is flagged as toxic.

SageThuja / white cedar Wormwood Artemisia absinthium

Research & Evidence

Beta-thujone is one of the two thujone isomers, a bicyclic monoterpene ketone found in wormwood, common sage, tansy and thuja. It is best known as a component of wormwood oil and therefore of absinthe, whose reputation for distinctive effects was historically attributed to thujone. It acts as an antagonist at GABA-A receptors, which underlies its convulsant potential at high doses.

Toxicity & Safety

Thujone is toxic in sufficient quantity: by blocking inhibitory GABA-A signalling it can cause restlessness, muscle spasms and, at high doses, seizures. For this reason the thujone content of foods and alcoholic drinks is legally limited, and wormwood and sage essential oils are not recommended for internal use, particularly during pregnancy. Ordinary culinary use of sage provides only trace amounts.