hepped up on (something)

hepped up on (something)

slang Feeling the effects of a particular substance, often (but not always) an illicit drug. I'm all hepped up on caffeine and ready to work on this project! His behavior has been so strange that I'm starting to wonder if he's hepped up on pills. Mom, thanks for watching the kids, but please don't get them all hepped up on sugar.
See also: hep, on, up