Lithium serves a dual role, crucial in low amounts for biological functions but harmful in high concentrations, as demonstrated in a study involving yeast species Saccharomyces cerevisiae, Candida albicans, and HeLa cells. In yeast, elevated lithium disrupts fermentation, leading to nutrient build-up and reduced ethanol production, showcasing its impact on cellular metabolism. In human HeLa cells, lithium offers therapeutic potentials at lower doses, particularly in treating mood disorders, but causes cellular damage when levels are too high. The research highlights the necessity of precise lithium dosage to balance its beneficial and detrimental effects. These findings underscore the intricate connections within biological systems and the importance of careful lithium use in environmental and health contexts. This emphasizes the interconnectedness in the web of life, where each element plays a crucial role.