INTRODUCTION: The spread of counterfeit drugs represents a serious threat to public health because they may be ineffective or cause the onset of severe suspected adverse drug reactions (ADRs). To date, the traceability of semaglutide-based products, widely used off-label for weight loss, is not a well-studied area.
METHODS: The aim of this study was to perform a descriptive analysis to explore and describe the characteristics of safety cases related to potential counterfeit semaglutide products by using the European pharmacovigilance database EudraVigilance. Individual Case Safety Reports (ICSRs) were retrieved over the period from 1 January 2018 to 31 December 2025.
RESULTS: A total of 234 Individual Case Safety Reports (ICSRs) related to potential counterfeit semaglutide were retrieved from EudraVigilance, of which N = 172 (73.5%) were related to females and N = 83 (35.5%) to adult patients. A total of 89.3% of all suspected ADRs were serious. The most frequently reported suspected ADRs were "vomiting", "nausea", and "hypoglycemia". The analysis of disproportionality showed a higher reporting frequency of "hypoglycemia", "product use in unapproved indication", "malaise", and "drug ineffective" with potential counterfeit semaglutide compared to non-counterfeit semaglutide.
DISCUSSION: The present pharmacovigilance study showed a useful role in identifying potential counterfeit medicine suspected ADRs. Further studies are warranted.