PQQ is a small quinone molecule that was first identified as a co-factor for certain enzymes. Recent research has shown that PQQ possesses antioxidant properties, which help protect cells from oxidative stress. It is involved in the regulation of multiple biological processes, including cell signaling, gene expression, and mitochondrial biogenesis—the process by which new mitochondria are formed. Mitochondria, often referred to as the powerhouses of the cell, are essential for energy production.