In addition, patchouli essential oil is said to act as an insect repellent, promote healing from burns and wounds, reduce inflammation, and alleviate stress. Whenused in skin-care products, patchouli essential oil is thought to treat oily skin and reverse signs of aging. Patchouli oil is an essential oil derived from the leaves of thepatchouli plant, a type of aromatic herb. In order to producepat chouli oil, the leaves and stems of the plant are harvested and allowed to dry out. They then undergo a distillation process to extract the essential oil.