Mastic Gum contains natural resin from the mastic tree (Pistacia lentiscus), also called mastiha, a shrub-like tree grown mainly in Greece and Turkey. Composed of a resinous exudate, containing essential oils, mastic gum has been used for centuries by traditional healers for stomach distress.* Mastic Gum supports the health of the gastric and duodenal cells and tissues as well as healthy levels of stomach acid production.*