mythological in the sense that all sorts of people build up myths about it and it's supposed powers.
( blinding flashes of insight, make you throw yourself off buildings, make you a god, make you an ant, turn your world inside out, heal all traumas, traumatize the most mentally sound, etc. etc. )
Now while there has been some scientific study of LSD's biopharmacology there is an unfortunate tendency for researchers to sample the product and then become evangelists for the drug. Which tends to render their methodology suspect; Leary being only the most notorious example.
This is false, LSD is the most researched psychedelic of them all and while we're not entirely sure of the mechanics of its actions (nor do we know of any of these kinds of brain mechanics, that's why the prescription of anti-depressants seems to be more of a guessing game than a science), we're definitely sure of a few things that occur.
LSD is not a unicorn.