Macrophyte extracts inhibit cyanobacteria growth, offering a sustainable solution for bloom control. The present study aimed to evaluate the response of Microcystis aeruginosa to aqueous extracts obtained from the dried biomass of Pistia stratiotes L. and Pontederia crassipes Mart. Solms. The parameters analyzed were cyanobacterial growth, photosynthesis, generation of reactive oxygen species, and antioxidative response. The chemical profile of the aqueous extracts upon incubation was also analyzed. Both extracts (4.0 g.L