Another D1 Agonist/D2 Antagonist to look into is (-)Stepholidine
https://en.wikipedia...ki/Stepholidine
It is found in Stephania intermedia, and is actually a fairly well known herb in Chinese medicine. In addition to the dopaminergic effects, it also has weak 5-HT1A agonism, which is not exactly unhelpful, here (downstream, modulating the α2-adrenergic receptors).
Overall it's a promising candidate, but I am having problems finding a source for it that is reasonably priced, as is the case with most ingredients from TCM.
I'm doing some digging around for this one, Stepholidine in itself seem to be "insanely" expensive, but related root extracts of the Stephania family seem to not be that expensive by the Kg on alibaba (yeah, China).
Anyone else can chime in about the potential value of Stephania intermedia?
Oral bioavailability and brain penetration of (−)-stepholidine, a tetrahydroprotoberberine agonist at dopamine D1 and antagonist at D2 receptors, in rats
http://www.ncbi.nlm....les/PMC2782339/