You can still purchase psychoactives by using bitcoin.
Silk Road might have been the No. 1 site for purchases of the kind but since the RC-market* has flourished the last years you can just buy a virtual visa through bitcoinpayout for example and then order some RC that's both legal and cheaper than street-drugs.

*RC = Research Chemical, a psychoactive substance that has not yet become illegal. Often poorly documented (side-)effects and therefore cheap. Commonly purchased from web-shops.