Help to get Mad Monica inside compound (5,4)
I believe the answer is:
amino acid
'compound' is the definition.
(amino acid is a kind of compound)
'help to get mad monica' is the wordplay.
'help' becomes 'aid' ('aid' can be a synonym of 'help').
'to get' is an insertion indicator.
'mad' indicates an anagram.
'monica' is an anagram of 'minoac'.
'aid' going around 'minoac' is 'AMINO-ACID'.
'inside' is the link.
(Other definitions for amino acid that I've seen before include "compound for life" , "Organic compound in proteins" , "source of protein required?" , "Chemical" , "Basic protein constituent" .)