Absinthe isn't a hallucinogen, it's an alcoholic drink. It produces as different of an effect as whisky does in comparison to vodka, but It's doesn't make you see things that aren't there.
If it's distilled properly, it's absolutely no more harmful than any other alcoholic beverage.
Most of the kinds that the majority of people here have tried are absolutely horrid fake knock offs produced in the Czech republic, home brewed garbage made here, or a weak version that is now legal in the U.S.
There are only a few legitimate brands of Absinthe out there, and in all the places that I've travelled in the world, I've found more fake absinthe than real stuff. Even Amsterdam, where you can get all sorts of other things, poured an oil based knock off at every bar that I asked about it in.
If you want decent absinthe, try this:
Jade Liquors Eduord
or try this:
PF 1901 Which is a nod to Pernod Absinthe.
Another thing; Absinthe is expensive. If you buy a $20 bottle of absinthe, you might as well know you were probably paying to have some guy in Romania piss into a bottle and sell it to you. You weren't getting real absinthe.