Absinthe thujone is the chemical present in Absinthe’s vital ingredient, the plant known as Common Wormwood, or Artemisia Absinthium to give it its botanical name. The chemical thujone was partly responsible for Absinthe being banned in the early 1900s in several countries across the globe and thujone is still tightly regulated today www.absinthesupreme.com, particularly in the United States (or states united).
Thujone was considered to be much like THC seen in cannabis and Absinthe was alleged to be psychoactive and have psychedelic effects causing hallucinations and insanity. Absinthe was popular with the Bohemian set in Montmartre in Paris and lots of artists and writers claimed that Absinthe, the Green Fairy, gave them inspiration in addition to their genius. Well-known Absinthe drinkers include Oscar Wilde, Ernest Hemingway, Van Gogh, Gauguin, Degas, Baudelaire and Verlaine. Some say that Van Gogh’s madness was due to Absinthe and that he cut off his ear under its influence 
. Absinthe was even held accountable for a man murdering his family, although he had used many other strong alcoholic drinks right after the Absinthe.
Prohibition campaigners used news of the murder to campaign for the banning of Absinthe and blamed France’s growing problems of alcoholism to the emerald liquor.
Is Absinthe Thujone Dangerous?
Today’s research suggests that it was actually the alcohol (ethanol) content of Absinthe which was dangerous instead of the thujone. Absinthe is doubly strong as spirits like whisky and vodka and can be 75% alcohol. Care should therefore be used when ingesting Absinthe. Thujone is only found in minute quantities and ought to therefore cause no major unwanted effects or health issues. The EU stipulates that alcohol based drinks with an ABV (alcohol by volume) level over 25% may only consist of a maximum of 10mg/kg of thujone, beverages classed as “bitters” can contain as much as 35mg/kg, it is not entirely clear which class Absinthe suits but a majority of brands of Absinthe have much less than 35mg with a lot of being under 10mg/kg. In the US it is just legal to buy or sell Absinthes with trace quantities of thujone.
High doses of thujone may be dangerous causing convulsions nevertheless you would need to drink a substantial amount of Absinthe to consume that quantity of thujone and it might be impossible to drink that amount, you would be comatosed from alcohol until then!
Absinthe Components
It is known that Henri-Louis Pernod, who owned the initial Absinthe distillery, employed the herbs wormwood, aniseed, fennel, lemon balm, hyssop, angelica root, dittany, star anise, nutmeg, juniper and veronica to create his famous Pernod Absinthe. The essential oil from all of these herbs is responsible for La Louche, the clouding which happens when water is included with Absinthe. These herbs especially the aniseed and anise are accountable for the distinctive aniseed or licorice taste of Absinthe and wormwood is liable for the bitter flavor. Absinthe is usually used as bitters in cocktails.
There are lots of brands of Absinthe or Absinthe substitutes that were developed during the ban and thus contain no Absinthe thujone or wormwood, however, many would state that Absinthe just isn’t Absinthe without Absinthe thujone and the bitter taste of wormwood. If you wish real Absinthe look for brands that contain wormwood or Absinthe thujone.