Early in his life he would have been a very regular user. He mentioned he had only taken DMT 40ish times. He noted this was a lot for DMT. I imagine he had 1000+ mushroom trips, but toward the end of his life he stopped taking mushrooms for 8 years after a particularly tough trip. This wasn't known publicly for several years after his death. Heres a long blog piece about a fan who originally felt betrayed by this. Worth a read. www.erowid.org/columns/teafaerie/2012/10/30/the-terence-mckenna-thing/
he said micrograms, he was talking about the psilocybin in the mushrooms, so a concentrated form of the pure compound, like in a pill form, MAPS is doing LSD and MDMA studies right now like this
+Ramteen Lol go foe it, I took 7 grams outside at night once, all I saw was pure electricity, I did some research after and I'm pretty sure what I saw was the morphogenetic field