This is completely counterproductive. We would suggest: a few seconds of mild discomfort during the treatment. All the reader remembers is 'needles' and 'hurt'.We also write Stakeholder and stock exchange announcements, wearing the same copywriting cap. 

Web-copywriting is an a craft, where we bow to the greater good that is the search engine. Writing for this greedy demanding and capricious technobot with boost online traffic.