OBJECTIVES: Social media’s increasing popularity globally as a communications tool extends to communications concerning patient healthcare experiences.  Social media may offer an untapped resource of pharmacovigilance data.  We hypothesized that social media listening may be well-suited to monitor the benefit-risk of a prescription-to-OTC switch product during the early post-launch phase. METHODS: Prescription Flonase™ (fluticasone propionate nasal spray) has been marketed globally for over 20 years. All publicly available, English posts from Facebook and Twitter referencing Flonase™ between 01Feb2014 to 30Apr2015 were obtained and de-identified.  5479 posts were categorized into two groups: three months post-launch and one year pre-launch as comparator.  Questions were pre-determined to assess benefit-risk of the OTC product. Posts were manually reviewed for extraction of pertinent data. RESULTS: Average monthly social media posts increased 8-fold during an OTC marketing campaign.  An increased post-launch monthly volume (87 proto-AEs/month) of social media confirmed proto-AEs (post resembling an adverse event) compared with pre-launch (17 proto-AEs/month) was observed, but at a lower percent (pre-launch: 11%, post-launch: 7%) of total posts.  Monthly rate of confirmed proto-AEs from social media increased over 400% from pre-launch versus a 47% increase of spontaneous AEs.  Over 25% of posts mentioned indication which allowed for monitoring of indication including off-label use. CONCLUSIONS: Social media provided a supplemental source of pharmacovigilance data allowing for assessment of the benefit-risk profile of a prescription-to-OTC switch product in the early post-launch phase.  The increase in rate of confirmed proto-AEs from social media listening compared to spontaneous reporting post-launch demonstrated that social medial data has the ability to quickly identify increased activity related to safety with a newly launched prescription-to-OTC switch product. Safety data obtained from our project were consistent with the known benefit-risk profile of Flonase™.  More research is needed to fully understand the value of this tool within pharmacovigilance.