You could always order some Kratom(Mitragyna speciosa) extract! It feels very similar to opiates and is legal in the US. It will also stop you from getting dope sick(if you get like that when you run out of pills). I have given this plant to many people, 1 in a wheelchair with a spinal injury. He told me it is the ONLY thing that has gotten rid of the pain, and was amazed when I told him it was legal. Just don't try to sell it to people for consumption, it's not been evaluated by the FDA yet. Web sites sell it as incense, but in Malaysia they use it as an opium substitute. They also treat opium addiction with Kratom in some countries.
You could even grow it yourself, but the tree needs to be protected from frost and cold temps.