Gallic acid is a phenol found in various plants including sumac, oak, and witch hazel; it exhibits neuroprotective, antioxidative, anticancer, anti-metastatic, antibiotic, antacid, and anti-ulcerative activities. Gallic acid is commonly used as a standard for determining phenol content of analytes. Gallic acid scavenges ROS and displays benefit in animal models of cerebral ischemia/reperfusion. Gallic acid also induces Fas-mediated apoptosis in breast cancer cells and induces apoptosis and inhibits migration in osteosarcoma cells. This compound inhibits the production of α-hemolysin and cell adhesion in Staphylococcus. Additionally, gallic acid increases levels of glutathione peroxidase, glutathione, glutathione reductase, catalase, and superoxide dismutase and decreases levels of myeloperoxidase. In vivo, gallic acid decreases gastric acid secretion and ulcer formation.