Flourensia cernua DC, commonly known as hojasen or tarbush, is a medicinal plant used in arid regions due to its therapeutic properties, especially in the treatment of gastrointestinal disorders. This study aimed to assess the toxicity of a polyphenolic extract obtained from F. cernua. This research involved both in vitro (hemolytic and brine shrimp assay) and in vivo tests (acute oral toxicity) to determine the safety profile of this extract. The extract was obtained through a novel ultrasound‐microwave extraction and purified by ion‐exchange chromatography. Analysis of the polyphenolic extract revealed a rich composition of flavonoids and hydroxycinnamic acids, mainly apigenin glycosides. In toxicity tests, the polyphenols did not exhibit toxicity towards Artemia salina at a concentration of 1 mg/ml. Furthermore, incubation at 500 μg/ml for 4 hours showed a slight toxic effect on erythrocytes. In the acute oral toxicity test in mice, doses of 300 mg/kg and 2000 mg/kg did not result in animal mortality, indicating that the LD50 exceeds 2000 mg/kg. However, the higher dose induced signs of toxicity, including lethargy, drowsiness, piloerection, and a significant decrease in weight during the initial two days postadministration of the polyphenolic extract. In addition, histological analysis suggested potential kidney damage at the 2000 mg/kg dose. According to OECD guidelines, while the extract can be classified as category 5 (low acute toxicity) due to the absence of mortality at 2000 mg/kg, the observed signs of toxicity should be considered in the overall risk assessment. These findings highlight the potential of F. cernua in pharmaceutical and nutraceutical applications due to its high polyphenolic content. However, further investigations are necessary to explore the specific effects of the compounds present in the extract. In addition, continuous evaluation of its long‐term toxicity is essential to fully understand the extract’s safety profile and efficacy.
