Thujone is psychoactive. However, in the quantities found in most commercial absinthes, (including the much-touted Czech absinths such as King's Spirit), the levels are not enough to induce hallucinations, a high, or any other cheerfully anticipated side-effects. The music of the spheres, visits from the friendly neighborhood Green Fairy, and all other dramatic happenings are, sadly, not caused by the quantities of thujone one can easily imbibe through the liqueur.

Effects from too much thujone include convulsions, muscle spasms, anxiety, spasms, and death.