Green’s Dictionary of Slang

(drugs) heroin.

1960, 1975		Wentworth & Flexner DAS.
1963		M. Spillane Return of the Hood 9: He [...] went looking for me with a skinful of big H to keep his courage up.
1972		C. Bukowski Erections, Ejaculations etc. 142: And there was the Big C. Big H. And Hash. Mary. Name it.
1983		J. Byrell (con. 1959) Up the Cross 96: Mick the Musco could’ve settled for speed or big H or even coke.
1985		(con. 1968) D.A. Dye Citadel (1989) 302: Well, fuck me. The Big H, man.
2001		ONDCP Street Terms 3: Big H — Heroin.
2007		(con. 1962) in E. Bunker Stark 10: The title character is a hophead and a grifter out to fill his pockets with gelt – and fill his arm with big ‘H’.
2021		J. Ellroy Widespread Panic 12: My main men got hooked on Big ‘H’.