These are not controlled drugs, but like most prescription only drugs which have been deregulated many of these drugs are only allowed to be sold over the counter by a pharmacist
The reason is that there are drug interactions, plus reasons some patients cant take them, so the idea is the person selling them can check they will not harm the individual.
If you somehow illegally purchase a laqrge quantity and get away with it, there is a fair possibility that when you hand them out like smarties one or more of your patients will have a little or big problem. I am sure they or their relatives will show their gratitude via the courts.
There is nothing different about a scientist. If they are at risk of needing these drugs they should go to the pharmacist and buy them legally and safely