<![CDATA[General Background: Hyperlipidemia is a metabolic disorder associated with oxidative stress and lipid peroxidation that can affect erythrocyte characteristics. Specific Background: Gracilaria verrucosa contains bioactive compounds, including flavonoids, phenols, tannins, alkaloids, steroids, and saponins, with antioxidant properties relevant to hyperlipidemic conditions. Knowledge Gap: Further investigation is needed to determine the responses of erythrocyte indices, particularly Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH), and Mean Corpuscular Hemoglobin Concentration (MCHC), following Gracilaria verrucosa extract administration. Aims: This study aimed to determine the responses of MCV, MCH, and MCHC to Gracilaria verrucosa extract in hyperlipidemic male Wistar rats. Results: A laboratory experimental study using a pretest-posttest control group design was conducted in April–May 2026 with 25 male Wistar rats divided into five groups: negative control, positive control receiving simvastatin 0.18 mg/200 g body weight, and extract doses of 25, 35, and 45 mg/200 g body weight. Two-Way ANOVA showed significant treatment differences for MCV (p=0.000) and MCH (p=0.000), but not MCHC (p=0.178). The 25 mg/200 g body weight dose produced the most favorable responses for MCV and MCH. Novelty: The study evaluates three erythrocyte indices simultaneously across different Gracilaria verrucosa extract doses in a hyperlipidemic rat model. Implications: The findings indicate that Gracilaria verrucosa extract is associated with significant changes in MCV and MCH, while MCHC remained statistically unchanged. Key Findings Highlights Treatment significantly changed the erythrocyte volume index (p=0.000). Treatment significantly changed the mean hemoglobin content per erythrocyte (p=0.000). Cellular hemoglobin concentration remained statistically unchanged (p=0.178). Keywords : Hyperlipidemia, Gracilaria Verrucosa, Erythrocyte Indices, Mean Corpuscular Volume, Mean Corpuscular Hemoglobin]]>
