Gallic acid is a trihydroxybenzoic acid in which the hydroxy groups are at positions 3, 4, and 5. It has a role as an astringent, a cyclooxygenase 2 inhibitor, a plant metabolite, an antioxidant, an antineoplastic agent, a human xenobiotic metabolite, an EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor, an apoptosis inducer and a geroprotector. It is a conjugate acid of a gallate.