No. The safety of fisetin supplements for pregnant or breastfeeding women is not well-studied. While some flavonoids have been deemed safe during pregnancy, the specific effects of fisetin are unclear; therefore, these supplements are not recommended during this life stage.No. The safety of fisetin supplements for pregnant or breastfeeding women is not well-studied. While some flavonoids have been deemed safe during pregnancy, the specific effects of fisetin are unclear; therefore, these supplements are not recommended during this life stage.