Introduction: Intravenous iron formulations have been approved in Europe and North America for the treatment of iron deficiency if oral iron is not tolerated or not efficacious. Recently-developed intravenous iron formulations exhibit specific physicochemical and immunological properties, with distinct bioavailability, efficacy and safety profiles. Area of Interest: intravenous iron formulations safety and tolerability were reviewed in the framework of a Swiss expert meeting. This work focused on the specificity of each compound with emphasis on the practical aspects of its use. Expert Opinion: Adverse reactions in response to iv formulations can be categorized into two main types: hypophosphataemia and hypersensitivity. Hypophosphatemia follows administration of ferric carboxymaltose at a higher rate in comparison to other formulations, but is mostly mild, transient and asymptomatic. However, the decrease in serum phosphate following repeated administration of iron preparations can affect bone health, particularly in patients at risk for osteomalacia. Severe hypersensitivity reactions are the most lifethreatening adverse reactions to intravenous iron supplementation. Iron (III)- isomaltoside 1000 seems to induce severe hypersensitivity more often (RR 5.6 - 16.2) than ferric carboxymaltose. Further studies are needed to address issues of long-term safety in high dose and prolonged administration of intravenous iron preparations in case of chronic diseases.