I think all psychoactive substances are illegal to use in the UK but things like lions mane shrooms, Kava, kanna, and wild opium lettuce which are psychoactive but not scheduled substances are sold on Amazon and eBay.
Lophophora and trichocerus cacti and also papaver poppies are legal for ornamental use.
I'm not 100% sure about chemicals used for research. I guess unless it's listed as a psycho or scheduled substance it will probably be legal in a kind of grey area way.
Research chems used to be legal here and we could buy m-cat and 2fdck from places like China and Germany. Because people were using m-cat to go out raving and various other chems were being used, the UK put a ban on all psychoactive substances. This is a grey area and I imagine it would only be listed if it's been identified and listed as a controlled substance
I'm not 100% sure.
Let me find out for sure and I'll report back.
Nootropics are legal yet they are psychoactive.
Also, amanita muscaria, I ordered some of that from Etsy and it is a class A mushroom, so I guess it's how the substance is labelled
I'll find out for sure and report b