Remember that in Shadowrun you can take drugs in any vector you want. Psyche can be pills, slappatches, inhaler, cigarettes, or needles.
As for the chemical gland argument, I'll try my best. So a designer drug is a drug that is made to mimic the effects of another drug typically for legal reasons. Typically this is done by slightly altering the chemical formula or using a completely different formula that nonetheless has the same effect. Since Psyche is a designer drug, that means that there is an "original" drug that Psyche is mimicking. That drug might be natural.
Another is Psyche is likely some relative of Ritalin and that's an organic chemical (C14H19N02). I could see a genetically engineered bacteria being able to make it and thus you can create cells that can make it. I could be totally wrong and you need high temperatures or something to create it, but odds are the GM won't know either.
Basically it boils down to the GM's call since the description in Augmentation is way too ambiguous for all but the most clear cut cases (no Plutonium glands).