That’s a pretty vague definition. What is ‘mind altering’ really? Every day after birth we ingest substances that keep us healthy (or not!) and continually alter our chemistry until death. Sugars, coffee, tea, chocolate… even sleep and natural endorphins and dimethyltryptomene produced in our own brains drastically alter our perceptions from one day to the next. Even water or oxygen could even be considered ‘mind altering’ in that they allow your brain cells to function! What about books? My mind has been ‘altered’ more from great books than anything perhaps anything else! Ultimately, there is no ‘reality’ so there is nothing to alter. Only a vast infinity to explore.