Pyrroloquinoline quinone (PQQ) is a compound found in small amounts in foods like kiwi, green peppers, and fermented soybeans. People also take it as a supplement. Its main draw comes from antioxidant activity and a suspected role in mitochondrial health. Mitochondria are the parts of cells that produce energy.
A typical daily serving falls between 10 and 20 mg. Some trials have tested up to 40 mg per day. You can take PQQ with food or on an empty stomach. A meal might lower the chance of stomach discomfort.
Long term safety is not well mapped out. Skip this supplement if you are pregnant or breastfeeding. Some users report mild headaches or fatigue.