You could ask tye chinese venders here. Im not even sure scopalamine is a controlled substance. Its abuse potential is very low. I imagine its an involved synthesisy due to its tropane skeleton, but its easily extracted from Datura sp.
Iit's not any more a poison than any drug, its a tropane alkaloid, like cocaine or atropine, an antocholergenic, more of a delieriant than a hallucinogen. Gar less poisonous than 100s of chemicals people might ingest