Absinthe thujone is the chemical seen 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 early 1900s in many countries around the globe and thujone continues to be tightly regulated today https://absinthesupreme.com, especially in the United States (or states united).
Thujone was regarded as just like THC found in cannabis and Absinthe was speculated to be psychoactive and have psychedelic effects creating hallucinations and insanity. Absinthe was favored by the Bohemian set in Montmartre in Paris and lots of artists and writers believed that Absinthe, the Green Fairy, gave them inspiration in addition to their genius. Famous Absinthe drinkers include Oscar Wilde, Ernest Hemingway, Van Gogh, Gauguin, Degas, Baudelaire and Verlaine. Some say that Van Gogh’s madness was brought on by Absinthe and that he cut off his ear under its effect 
. Absinthe was even held responsible for a man murdering his family, despite the fact that he had consumed a great many other strong alcoholic drinks following the Absinthe.
Prohibition campaigners used news of the murder to campaign for the suspending of Absinthe and charged France’s growing problems of alcoholism to the emerald liquor.
Is Absinthe Thujone Unsafe?
Today’s studies suggest that it was actually the alcohol (ethanol) content of Absinthe that was dangerous rather than the thujone. Absinthe is doubly strong as spirits like whisky and vodka and can be 75% alcohol. Care should therefore be taken when consuming Absinthe. Thujone is just present in minute quantities and must therefore cause no major side effects or health conditions. The EU stipulates that alcoholic beverages with an ABV (alcohol by volume) level over 25% might only consist of a maximum of 10mg/kg of thujone, beverages classed as “bitters” can contain up to 35mg/kg, it’s not completely clear which class Absinthe matches but a majority of brands of Absinthe have much less than 35mg with many being under 10mg/kg. In the US it is only legal to get or sell Absinthes with trace levels of thujone.
High doses of thujone can be dangerous triggering convulsions but you will have to drink a substantial amount of Absinthe to consume that quantity of thujone and it will be impossible to drink that amount, you would be comatosed from alcohol until then!
Absinthe Formula
It is said that Henri-Louis Pernod, who owned the first Absinthe distillery, employed the herbs wormwood, aniseed, fennel, lemon balm, hyssop, angelica root, dittany, star anise, nutmeg, juniper and veronica to produce his famous Pernod Absinthe. The essential oil from all of these herbs is responsible for La Louche, the clouding which occurs when water is added to 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 oftentimes used as bitters in cocktails.
There are many brands of Absinthe or Absinthe substitutes that were developed over the ban and therefore contain no Absinthe thujone or wormwood, but some would claim that Absinthe just isn’t Absinthe without Absinthe thujone and the bitter taste of wormwood. If you want real Absinthe look for brands that contain wormwood or Absinthe thujone.