Hormone treatment for Linus inside home (7)
I believe the answer is:
insulin
'hormone' is the definition.
(insulin is a kind of hormone)
'treatment for linus inside home' is the wordplay.
'treatment for' indicates anagramming the letters (I've seen this in other clues).
'inside' is an insertion indicator.
'home' becomes 'in' ('he's home' can mean 'he's in').
'linus' with letters rearranged gives 'nsuli'.
'nsuli' going into 'in' is 'INSULIN'.
(Other definitions for insulin that I've seen before include "Hormone produced in the pancreas to control body sugar" , "Treatment for diabetes" , "Hormone controlling sugar intake, used for diabetes" , "Hormone lacking in diabetic" , "Hormone that controls the body's sugar absorption" .)