K is for fucking LOSERS!!
I never understood why any idiot would want to do K.
Bottom Line: All dissociatives carry a real risk of permanent brain damage. Dissociatives include ketamine, DXM, PCP, dizocilpine, and nitrous oxide (tho it may not be nearly so dangerous due to very short duration of action). Individual susceptibility varies greatly, so if you've snorted enough K to tranq an entire pet shelter and downed A. H. Robins' entire year's production of Robo and are still OK, this doesn't mean that everyone else can do the same thing. I've spoken with numerous people who have suffered permanent impairment from heavy dissociative use
People who have used dissociatives heavily have shown clear evidence of brain damage. This is not necessarily conclusive, since the people who become addicted to them might have underlying conditions (specifically, temporal lobe complex partial seizures) which could be responsible for some of the damage. Nonetheless, I can't ignore the fact that most everyone who uses dissociatives both frequently and heavily ends up with some sort of neurological or psychological problem, ranging from impaired memory to a schizophrenia-like syndrome. Many of the impairments correspond exactly to the areas of the brain damaged in lab animals.
It is a safe drug as in you can't OD on it but it will fuck your brain up if you do it enough.