Green’s Dictionary of Slang

hepped adj.

[hep adj. (1)]

(US) enthusiastic about, keen on; also constr. with on.

[US]J. Lait Put on the Spot 36: He’ll be hepped soon enough.
[US]N. Algren Neon Wilderness (1986) 120: Gladys wasn’t that hepped on chop suey.
[US]Sepe & Telano Cop Team 70: Oh, shit [...] You guys are hepped.

In phrases

hepped up (adj.)

1. (US) agitated, excited.

[US]M. Levin Citizens 141: The union boys got all hepped up.
[US]S. Bellow Augie March (1996) 71: The whole race was hepped-up about appliances.
[US]Thomas Anderson Your Own Beloved Sons 57: Major’s all hepped up about it.
[US]Baker et al. CUSS 136: Hepped up Eager for or looking forward to something or someone.
F. Walton Once Were Eagles 159: I was real hepped up to get assigned to the Black Sheep.

2. (US) intoxicated by drugs or alcohol.

[US]ATS 123: [Drunk] Hepped up...pifflicated [etc.].
Simpsons [Fox-TV] The guy’s hepped up on goofballs! [HDAS].

3. see hep adj. (1)