Green’s Dictionary of Slang

(US drugs) inferior quality cannabis.

1964		R.S. Gold Jazz Lex. 193: Lipton’s n. [because jazz slang tea means marijuana, a brand name of the standard sense of tea has become synonymous with all marijuana of poor quality — i.e., having no more effect on the smoker than . . .].
1965		W. King ‘The Game’ in King Black Short Story Anthol. (1972) 304: I’m dead, brother [...] I need a dime to get some Lipton.
2001		ONDCP Street Terms 14: Lipton Tea — Poor quality drugs.