Some Rodan + Fields products use ingredients that are controversial, toxic and may cause cancer. These include parabens, retinyl palmitate, benzophenone, hydroquinone and DMDM Hydantoin and Diazolidinyl urea, both of which release formaldehyde. Other customers have had issues with their serums causing swollen, crusty and painful eyes. In fact, there was a huge class action lawsuit in the U.S. in 2018.