Suspected adverse reactions to performance enhancing dietary supplements: Spontaneous reports from the Italian phytovigilance system

Herbal tonic and adaptogens are often used to improve overall well-being. However, few clinical evidence supports their use and their safety is not known before marketing. In this context, the aim of our study was to analyze the spontaneous reports of suspected adverse reactions (ARs) to performance enhancing herbal dietary supplements collected by the Italian Phytovigilance System. Between March 2002 and September 2020, 110 spontaneous reports were collected, 58 of which related to products containing botanicals, alone or in association. Twenty-three serious reactions were reported, 21 of which required hospitalization, one was life-threatening and another caused disability. Dermatological and cardiovascular reactions were the most frequent. Hepatic ARs were the most serious (9 out of 10). A positive dechallenge was indicated in 69% of cases, while a positive rechallenge occurred in 15%. Concomitant use of other products was present in 18 reports (31%), while predisposing conditions were indicated in 17 (29%). Present data highlight safety concerns on herbal dietary supplements used as cognitive and physical performance enhancers, mainly due to their quality and use without expert supervision. Considering that postmarketing surveillance is not required for these products, spontaneous reports represent the only tool to point out risks related to food supplements.