Saga Pro is a food supplement product manufactured in Iceland and marketed internationally. It is claimed to have anti-nocturia effect and the flavonoid isoquercitrin has been suggested to play a role in this assumed activity. The purpose of this study was to identify and quantify the main flavonoids and furanocoumarins in the SagaPro tablets and to evaluate the importance of their presence. Isoquercitrin was identified as a constituent in an amount of 158 μg/tablet. This is a p.o. dosage highly unlikely to have an effect on nocturia or any other pharmacologically significant effect in humans. The main furanocoumarins, xanthotoxin and imperatorin, were also identified and quantified to 280 and 2 μg/tablet, respectively.