Liberated female about to take drug (4)
I believe the answer is:
free
'liberated' is the definition.
(I've seen this before)
'female about to take drug' is the wordplay.
'female' becomes 'f' (abbreviation).
'about' becomes 're' (regarding**).
'to take' is a charade indicator (letters next to each other).
'drug' becomes 'e' (e is another name for ecstasy).
'f'+'re'+'e'='FREE'
(Other definitions for free that I've seen before include "with no toll demanded?" , "Liberal" , "Not working" , "Release; gratis" , "Under no obligation" .)