Plant used in homeopathy’s so produced (6)
I believe the answer is:
hyssop
'plant' is the definition.
(hyssop is a kind of plant)
'in homeopathy's so produced' is the wordplay.
'in' indicates the answer is hidden within the clue.
'HYSSOP' is hidden in the letters of 'homeopathys so produced'.
'used' acts as a link.
(Other definitions for hyssop that I've seen before include "Herb in the mint family" , "Aromatic herb" , "Aromatic plant" , "Small bushy plant with bitter minty leaves" , "little blue flowers" .)