Apparently so. The US Government has published a big list of them. Science keep out!
What are these realms too dangerous for science to investigate? Some Brobdingnagian force more powerful than nuclear fusion? Some hideous virus that could end all life on Earth? What monstrous horror lurks behind the forbidden door? Weak hearts should read no further. Are you ready?
The forbidden substance is---marijuana.
Yes, ma'm. Scientists can't study marijuana (without becoming criminals). And they can't investigate dozens of other perfectly normal molecules classified as Schedule 1 by our paternalistic bosses. These hysterically dangerous substances, legislated off limits to scientists, include mescaline, LSD, psilocybin. MDMA and more than a hundred other molecules you've never heard of. And marijuana too, of course. Hands off pot, Doc, unless you want to be locked up with murderers, armed robbers and rapists for a long, long time.
Are we living in the Middle Ages or what?
Fortunately some reasonable folks are trying to change this absurd situation for the better. One such group that's working to make science legal again is MAPS (Multidisciplinary Association for Psychedelic Studies) who are lobbying Congress, obtaining funding for research, and educating the public about the advantages of seeking knowledge rather than legislating ignorance about these substances "too dangerous for science to touch".
MAPS used to be located in Florida but has recently moved to Ben Lomond, CA, only a few minutes drive from my Quantum Tantra Ashram in Boulder Creek. Last year I stopped by, introduced myself and got to know these science-friendly strangers who persuaded me to contribute an article to their newsletter about Nick's first psychedelic experience way back in the '60s. It's called "Doctor Quantum Drops Acid" and is available in pdf form at http://www.maps.org/news-letters/v17n2-html/index.html. Lots of other good information on the MAPS site about how one might successfully investigate these substances that some people find glorious, life-enhancing and even divine while others find them so fearsome they will put clamps on normal human curiosity and make outlaws of scientists for merely doing their job--which is to explore the unknown, no matter how dangerous.
It's a bad situation. Call up your Congress critter and ask why he/she hates science so much.