Metabolites are small molecules that grow within cells in single and multicellular organisms, influencing protein structure to maintain life. They are sensitive to shifts in the whole organism, and environmental stressors can cause changes at the molecular level. At times, fluctuations in the levels of metabolites may underlie disease. Join Priyanka Joshi as she delves into the implications of understanding metabolites for aging, neurodegenerative diseases such as Alzheimer’s, and long-COVID.