One summer when 25i first hit the scene SWIM was taking 1000 to 5000 microgram doses weekly until one week SWIM dosed 1000 micrograms (pre dipped blotter) and the short version of the story is SWIM woke up in the hospital and was being monitored to prevent kidney failure due to elevated proteins in SWIM's blood.
Similar events which were all preceded by psychotic breaks with reality happened to quite a few of SWIM's friend group if you want some anecdata to add there.
It's scary stuff whose unpredictability means I wouldn't recommend touching it with a 10 foot pole.