Safety of herbal dietary supplements used for weight loss: sales data and phytovigilance awareness

Purpose Overweight/obesity is a metabolic risk factor contributing to chronic diseases. People use herbal dietary supplements (HDS) to promote weight loss, convinced in embracing a healthy attitude. As in Italy warnings concern weight loss-HDS, the aim of the study was to contextualize their safety by investigating sales data and phytovigilance awareness in territorial pharmacies. Methods Sales of weight loss-HDS were monitored from October 2018 to September 2020 in two pharmacies of Rome. Independently, a survey about phytovigilance was addressed to pharmacy owners of the Lazio region. Results From the overall sales, 9% of HDS, consisting of 122 brands, claimed weight loss. Among them, 76% were multi-ingredient with up to 29 components. Moreover, 158 plant species with variable/missing standardization and 49 non-botanical ingredients were clustered. In the 29 participants of the questionnaire, 70% knew phytovigilance, but only 25% of them knew the tool to report the suspected adverse reactions (ARs). Conclusions Given the variety of multi-ingredient formulations and plant species not strictly claimed for the weight loss promotion, variable standardization of botanicals, and a low adherence of pharmacists to report suspected ARs, this study highlights safety uncertainties of weight loss-HDS. Future efforts involving sales data of all territorial pharmacies and promotion of phytovigilance are required.