The role of FNDC5/Irisin in cardiovascular disease is reviewed, highlighting its involvement in various metabolic and physiological processes. Irisin, a myokine secreted by skeletal muscles, is also present in other tissues, with the highest levels in cardiomyocytes. It influences mitochondrial biogenesis, thermogenesis, and the conversion of white adipose tissue to brown adipose tissue. Irisin plays a protective role in cardiovascular diseases by reducing oxidative stress, apoptosis, and inflammation in cardiomyocytes. It activates signaling pathways such as AMPK, PI3K/AKT, and ERK1/2, which are crucial for cardiomyocyte survival and function. Irisin also promotes angiogenesis, enhances endothelial cell proliferation, and reduces vascular calcification. Studies show that increased physical activity leads to higher levels of irisin, which may have therapeutic potential in preventing and treating cardiovascular diseases. Irisin levels are associated with cardiovascular health, with lower levels linked to atherosclerosis and higher levels associated with reduced risk of cardiovascular events. However, elevated irisin levels may also contribute to oxidative stress and cardiomyocyte apoptosis. The review discusses the potential of irisin as a biomarker and therapeutic agent in cardiovascular disease, emphasizing the need for further research to elucidate its mechanisms and applications.The role of FNDC5/Irisin in cardiovascular disease is reviewed, highlighting its involvement in various metabolic and physiological processes. Irisin, a myokine secreted by skeletal muscles, is also present in other tissues, with the highest levels in cardiomyocytes. It influences mitochondrial biogenesis, thermogenesis, and the conversion of white adipose tissue to brown adipose tissue. Irisin plays a protective role in cardiovascular diseases by reducing oxidative stress, apoptosis, and inflammation in cardiomyocytes. It activates signaling pathways such as AMPK, PI3K/AKT, and ERK1/2, which are crucial for cardiomyocyte survival and function. Irisin also promotes angiogenesis, enhances endothelial cell proliferation, and reduces vascular calcification. Studies show that increased physical activity leads to higher levels of irisin, which may have therapeutic potential in preventing and treating cardiovascular diseases. Irisin levels are associated with cardiovascular health, with lower levels linked to atherosclerosis and higher levels associated with reduced risk of cardiovascular events. However, elevated irisin levels may also contribute to oxidative stress and cardiomyocyte apoptosis. The review discusses the potential of irisin as a biomarker and therapeutic agent in cardiovascular disease, emphasizing the need for further research to elucidate its mechanisms and applications.