Green’s Dictionary of Slang

p.h. n.

[abbr.; purple hearts under purple adj.]

(drugs) amphetamine pills.

[UK]J.P. Carstairs Concrete Kimono 61: I realized he had been hopped-up, probably on P.H.s.
[UK]T. Keyes All Night Stand 115: The Sinner Sect liked me, ever since I gave Sach fifty PH as a jokey sort of gift.