A therapeutically effective dose refers to {HEAD ~ that amount} of active ingredient, which ameliorates {TAIL ~ the symptoms} or condition 
A therapeutically effective dose refers to { HEAD ~ that amount } of active ingredient , which ameliorates { TAIL ~ the symptoms } or condition
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH