Green’s Dictionary of Slang

(drugs) to inject narcotic drugs irregularly, often just under the skin.

1936		see joy-popping n.
1958		W. Motley Let No Man Write My Epitaph (1960) 171: Fran joy-popped. Just hit with the stuff under the skin.
1959		W. Brown Teen-Age Mafia 6: I like to joy-pop sometimes. [...] I like a little horse now and then to set me up.
1960		C. Cooper Jr Scene (1996) 85: I’m glad I don’t use [...] I’m glad I don’t do nothin but joy pop.
1971		R.D. Pharr S.R.O. (1998) 189: ‘You know Champ and Earnest joy-pop sometimes .
1993		Tarantino & Avery Pulp Fiction [film script] 58: I don’t go joy-poppin’ with bubble-gummers.
2001		ONDCP Street Terms 13: Joy pop — To inject a drug.