PQQ is a redox cofactor that plays a crucial role in mitochondrial function and energy metabolism. It is found in various foods, including fermented soybeans, green peppers, and spinach. PQQ is notable for its ability to stimulate the growth of new mitochondria, a process known as mitochondrial biogenesis. This function is particularly important as mitochondria are the powerhouses of the cell, converting nutrients into energy. More mitochondria can lead to increased energy production, which is especially beneficial for active individuals and those experiencing fatigue.