Cut price of drug for grown-ups? (10)
I believe the answer is:
adulterate
'cut price' is the definition.
'adulterate' can be an answer for 'cut' (I've seen this before). I'm not sure about the 'price' bit.
'drug for grown-ups?' is the wordplay.
'drug' becomes 'e' (E is another name for ecstasy).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'grown' becomes 'adult' (synonyms).
'ups?' becomes 'rate' (I can't justify this - if you can you should give a lot more credence to this answer).
'e' put after 'adult' is 'adulte'.
'adulte'+'rate'='ADULTERATE'
'of' is the link.
(Other definitions for adulterate that I've seen before include "Corrupt" , "Make impure by addition" , "Water down" , "add inferior material?" , "cut" .)