PQQ (Pyrroloquinoline quinone) is a small quinone molecule which acts as a REDOX agent, allowing it to reduce oxidants before being recycled back into an active form by glutathione, making it capable of acting again as an antioxidant. The main benefit of PQQ supplementation is its ability to support the production and effective function of mitochondria, which play the key role of converting nutrients into energy which can be used by cells. There is also research suggesting PQQ may be beneficial for supporting cardiovascular and cognitive health.