Help fellow medic puff out hair (8)
I believe the answer is:
backcomb
'puff out hair' is the definition.
'help fellow medic' is the wordplay.
'help' becomes 'back'.
'fellow' becomes 'co' (I've seen this in other clues**).
'medic' becomes 'mb' (Bachelor of Medicine).
'back'+'co'+'mb'='BACKCOMB'
(Other definitions for backcomb that I've seen before include "Style hair to be thicker" , "to make hair look thicker" , "tease" , "Give (hair) a fuller appearance" .)