Interpreting data on alpha-lipoic acid safety considering the number of subjects exposed.

We have read with attention and interest the recent paper of Raschi et al. [1], analysing spontaneous reports of suspected adverse reactions to alpha-lipoic acid included in the Italian hytovigilance System (IPS). The conclusion of the authors suggests the need for a strong attention to the use of alpha-lipoic acid because of an unpredictable risk of serious side effects. However, we would like to stress some concerns about these data interpretation. In the paper of Raschi et al. [1] the reports regard different dietary supplements (with different production quality and associated with different components), different kind of patients (often assuming other drugs at the same time) and very rarely with a reported treatment rechallenge. [...]