use attached file, the F18 cell formula

=IF(E13>0,IF(((($H$11=4)1)(($E$20=0)*1)((IF(H2=1,($E$4$E$10*$E$11*$E$13),($E$4*E8*$E$10*$E$11*$E$13))=0)*1))>0,""," mL bottle (~ "&$G$46&" oz.)"),IF(E18="Data?",""," Length of therapy?"))