What is PQQ
PQQ is a unique nutrient that is essential for growth and development. It acts as an antioxidant within your cells, counteracting free radical damage. PQQ also helps your cells communicate.
Protects Brain Health
PQQ stimulates normal levels of nerve growth factor production, which, in turn, protects nerve cells and supports healthy nerve cell growth. 
Improves Learning & Memory
PQQ also supports your cardiovascular system with its potent antioxidant and mitochondria-making properties.
 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3303106/