MDMA with powder taken up brings striking effect (5)
I believe the answer is:
eclat
'striking effect' is the definition.
(I've seen this before)
'mdma with powder taken up' is the wordplay.
'mdma' becomes 'E' (MDMA is ecstasy, ie 'E').
'with' means one lot of letters go next to another.
'powder' becomes 'talc' (talcing is a kind of powdering).
'taken up' says the letters should be written backwards.
'talc' written backwards gives 'clat'.
'e'+'clat'='ECLAT'
'brings' is the link.
(Other definitions for eclat that I've seen before include "French social distinction or success" , "Brilliant display -- conspicuous success" , "Ostentation" , "Enthusiastic approval" , "Brilliant success - striking effect" .)