Recovering as a result of continuously swallowing them (2,3,4)
I believe the answer is:
on the mend
'recovering' is the definition.
(on the mend means recovering or recuperating)
'continuously swallowing them' is the wordplay.
'continuously' becomes 'on end' (eg in a phrase like 'for weeks on end').
'swallowing' is an insertion indicator.
'onend' placed around 'them' is 'ON THE MEND'.
'as a result of' acts as a link.
(Other definitions for on the mend that I've seen before include "Making recovery" , "Looking up" , "Regaining health" , "returning to health" , "undergoing recovery?" .)