Is there any permanent damage from smoking k2?

There can be: First of all, you do not know what you are getting when you buy drugs labeled as spice, k2 or any of a large number of names - each batch can be chemically different, let alone different brands. Kidney damage with kidney failure, convulsions, malignant hyperthermia (body temperatures over 105) have been reported, and these can have permanent health effects, including death. Psychosis can occur.