LCC-12, a derivative of the biguanide metformin, acts as a copper (II) chelator. It efficiently forms a monomeric bond with copper (II) and at 20 µM, it mitigates hydrogen peroxide-induced oxidation from NADH to NAD+. At a concentration of 10 µM, LCC-12 significantly reduces the secretion of cytokines IL-1β, IL-2, IL-6, IL-8, and TNF-α, along with the downregulation of JAK2, STAT2, and IL-1 receptor-associated kinase 4 (IRAK4) in primary human cytokine-activated monocyte-derived macrophages (MDMs). Additionally, it decreases the presence of CD80+ and CD86+ within these macrophages at 10 µM. When administered at 0.3 mg/kg per day, LCC-12 enhances survival rates in mouse models exposed to sepsis, triggered either by lipopolysaccharide (LPS) or cecal ligation and puncture.