see that pathway that converts tryptamine to N-methyltryptamine? well, it's thought double-pass metabolism of tryptamine occurs to further convert it to DMT. see how it's a completely separate pathway from  serotonin --> melatonin?

INMT (E.C. # 2.1.1.49) isn't expressed in the pineal gland, and i've yet to see any lit. that claims otherwise.

peripheral tissues are non neural-tissues; the currently accepted theory is that INMT is expressed in these (lung, adrenal, and muscle tissues). evidence for its expression in the brain is scant