All this brain chemistry is extremely interesting to me, but I don't have much of a background in metabolic pathways/biology.  so if I am reading this correctly, tryptophan can lead to N-methylserotonin, which is an analog of N,N-DMT (I see that serotonin has an additional hydroxy group as well as lacking a N-methyl group)?  the enzymes which catalyze the creation of this molecule (neurotransmitter) don't occur in the pineal gland?

could someone expand on the peripheral tissue?  does that mean skin?

lots of questions I know, but I'm a chemist so I'm used to everything being in a shiny glass tube.