Stout doctor essentially makes you better (5)
I believe the answer is:
outdo
'better' is the definition.
(thesaurus)
'stout doctor essentially' is the wordplay.
'essentially' indicates the answer is hidden within the clue (essence can mean the inside of something).
'OUTDO' can be found hidden inside 'stout doctor'.
'makes you' is the link.
(Other definitions for outdo that I've seen before include "Overtake" , "Exceed" , "Best" , "Br superior to (someone)" , "Surpass - overshadow - excel" .)