<p>Artemisinin, betulinic acid, and succinic acid are among the secondary metabolites identified in the 50% ethanolic extract of <i>Clinacanthus nutans</i> (Burm.f.) Lindau, Acanthaceae, leaves, noted for their potential immunomodulatory activity and ability to influence immune responses. However, the underlying immunological mechanisms of these compounds remain largely unexplored and warrant further investigation. This study aimed to evaluate the effects of artemisinin, betulinic acid, and succinic acid on J774.2 macrophages, focusing on phagocytosis and reactive oxygen species production. Cell cytotoxicity was assessed using the MTT assay. Phagocytic activity was measured via fluorescence microscopy and flow cytometry using pHrodo™ Green <i>Escherichia coli</i> bioparticles. Additionally, reactive oxygen species levels were evaluated with the 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA) dye and flow cytometry. Based on MTT assay results, a concentration of 1&#xa0;µM and an incubation period of 48&#xa0;h were selected for all three metabolites. The effects of the compounds on macrophage phagocytosis and reactive oxygen species generation were phenotype specific. Artemisinin significantly increased phagocytosis in M0 cells (<i>p</i> &lt; 0.05) but reduced it in M1, while betulinic acid suppressed M1 and M2 phagocytosis (<i>p</i> &lt; 0.05). Succinic acid significantly decreased phagocytic activity in M0 and M1 (<i>p</i> &lt; 0.05). All compounds decreased reactive oxygen species levels across M0, M1, and M2 macrophages, with artemisinin maintaining the highest reactive oxygen species among treated groups and succinic acid showing the strongest suppression. These findings suggest that each compound modulates macrophage function differently, with potential applications tailored to specific immune states. Rather than a broad effect, their actions support selective therapeutic use based on macrophage phenotype and disease context.</p> Graphical Abstract <p></p>