The most popular misconception about absinthe is that it is a drug, or at least similar to a drug in effect. This is not true. The hysteria surrounding absinthe in the early 20th century fueled the misconception that absinthe was a powerful intoxicant, caused hallucinations that drove men "mad", threw them into epileptic fits, and made Van Gogh slice off his ear. The truth however, is both more interesting and less sensational:
Absinthe differs from almost all other drinks in containing a higher percentage of alcohol - up to 72% - and of course in containing extract of wormwood
, or Artemisia absinthium, to give it its correct Latin name. Wormwood is a herb related to the daisy family that grows wild in many areas of Europe. From ancient times it has been prized as one of the most valuable medicinal herbs
. An Egyptian papyrus from 1600BC recommends wormwood as a stimulant and tonic, an antiseptic, and a remedy for fevers and period pains. Pythagoras thought that wormwood leaves in wine would ease childbirth, and Hippocrates also recommended it for period pains, as well as anemia and rheumatism. Today, wormwood oil, the oil obtained from Artemisia absinthium, is used as a counter-irritant in many common over-the-counter pharmacy products, including Vicks Vaporub.
The chemical name for the principle active ingredient in wormwood is thujone. Thujone is a terpene and is related to menthol, which of course is known for its healing and restorative qualities. In its chemically pure form, it is a colourless liquid with a menthol-like aroma. Oil of Artemesia absinthium is typically approximately 60% thujone. Thujone – pronounced "thoo-jone" with a soft 'J' – is a naturally occurring substance, also found in the bark of the thuja, or white cedar, tree, and in other herbs besides wormwood - including tansy and the comon sage used in cooking. Aside from absinthe, other popular liquors, including vermouth, Chartreuse, and Benedictine, also contain small amounts of thujone. In fact, vermouth, which was originally made using the flower heads from the wormwood plant, takes its name from the German "wermut" ("wormwood").
Extremely high doses of thujone are however dangerous, and have been shown to cause convulsions in laboratory animals, but the concentration of thujone actually found in absinthe is many thousands of times lower than this. Thujone's mechanism of action on the brain is not fully understood although certain structural similarities between thujone and tetrahydrocannabinol (the active component in marijuana) led to some speculation in the 1970's that both substances have the same site of action in the brain. More recent scientific research however has completely discredited this idea.
Some researchers have now hypothesised that the reputed "secondary effects"
of absinthe have nothing directly to do with thujone at all - if they in fact exist at all, they may be caused by the interaction of some of the other constituent herbs ( fenchone in fennel, pinocamphonethe in hyssop, and the anethole in anise, have all been shown to cause epileptiform convulsions in laboratory animals when administered in very large doses).
The effect of well-made absinthe varies from person to person, but is typically no more marked than the mild “buzz” one gets from drinking tequila. Generally, it can best be described as a kind of heightened clarity of mind and vision, warmed by the effect of the alcohol. This seems to wear off after 20 or 30 minutes. Some users report unusually vivid dreams. Since absinthe is 55% -72% alcohol, the alcohol's effects will in any event limit the amount of thujone you can ingest. Most modern “legal” absinthes, in keeping with EU regulations, contains less than 10mg of thujone per litre, and recent research has shown that pre-ban Pernod Fils, contrary to ill-informed speculation by several authors, including Strang and Arnold in a widely quoted 1999 British Medical Journal article, also had relatively low thujone levels.
Increasingly it seems clear in fact that well-made absinthes following authentic traditional recipes seldom have thujone levels much in excess of 35mg/l the EU standard for thujone in bitters (a category that can, in practice, include absinthe), and many quite naturally fall under the 10mg/l level. It seems that irrespective of the quantity of wormwood used, relatively little thujone makes it through the distilling process into the final distillate. So the entire historical demonization of absinthe based on its allegedly high thujone content now appears to have been based on a wholly false premise.
The high thujone levels claimed by many Czech and German made "absinths" are invariably false (in fact, someof these products, when analysed by gas chromatograph and mass spectrometer, show no detectable thujone at all). As a rule of thumb, any absinthe claiming exceptionally high thujone levels should be avoided, as it's almost certainly a poor quality oil-mix, supported by bogus marketing hype.