Absinthe is regulated by the Food and Drug Administration and, until recently, was completely banned in the U.S. and most of Europe.

The reason for this is that absinthe contains thujone, a toxic chemical found in several edible plants including tarragon, sage, and wormwood. Why is thujone so dangerous that its presence in your glass of booze needs to be regulated by the FDA? The answer has more to do with history than science.

Prior to the ban in the early 1900s, absinthe was ubiquitous. If you check out a list of famous people who drank absinthe, you’ll notice that there’s a lot of them. That’s because basically everyone who was cool between 1850 and 1900 drank it. Being both the latest fad in booze and extremely high in alcohol content, absinthe was sometimes to blame for bouts of raging drunkenness, occasional delirium, and even death.

As its popularity spread, incidents of absinthe-related alcohol abuse spread as well. Society gradually came to associate absinthe with alcoholism and degeneracy in general. A French psychiatrist named Dr. Valentin Magnan even went so far as to blame absinthe for what he saw as a collapse of French culture.

Dr. Magnan set out to prove through scientific experiment that absinthe was the root of French society’s ills. He conducted all sorts of scientific experiments on animals using thujone and wormwood oil. He observed that mice that ingested high concentrations of thujone had convulsions and died. He even gave a dog a vial of wormwood oil and watched it go crazy and bark at a brick wall for half an hour. (This experiment, by the way, is the root of the myth that absinthe causes hallucinations. It doesn’t.)

These and other experiments seemed to confirm the common sense of the day: Absinthe caused people to go crazy. It became common knowledge that wormwood had madness-inducing and psychoactive powers.

Then, in 1905, a Swiss man named Jean Lanfray murdered his wife and two daughters in a drunken rage one night. Lanfray had been drinking absinthe (as well cognac, brandy, crème de menthe, wine, and beer) since breakfast, and the day before, and the day before, and the day before. The Lanfray trial put absinthe in the spotlight.

Combined with the evidence produced by Dr. Magnan, the crime was added to the narrative of the Temperance Movement, which advocated a ban on absinthe. By the early 1900s, the spirit was banned in most of Europe and the United States. The bans persisted for over a hundred years.