Dummy pill (7)
I believe the answer is:
placebo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dummy pill</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for placebo that I've seen before include "Innocuous medication; palliative" , "Innocuous or inert medication" , "Measure purely to calm or humour another" , "ineffective medicine" , "Medicine working by psychology only" .)