Hallucinogen produced from stale dung (5,4)
I believe the answer is:
angel dust
'hallucinogen' is the definition.
(angel dust is a kind of hallucinogen)
'from stale dung' is the wordplay.
'from' indicates anagramming the letters (from the letters).
'stale'+'dung'='staledung'
'staledung' is an anagram of 'ANGEL DUST'.
'produced' is the link.
(Other definitions for angel dust that I've seen before include "Hallucinogen - stale dung (anag)" , "Drug" .)