doTERRA essential blend oils are doTERRA's unique product line that maintains the characteristics of pure single oils, but selects and harmoniously blends oils that are more effective when mixed together. It is the best result of combining traditional manufacturing methods passed down for a long time with advanced technology based on scientific research. Zendocrine Blend Oil is doTERRA's unique blend oil extracted from the flowers, leaves, and fruits of plants such as mandarin, rosemary, juniper berry, and geranium and mixed in a special ratio. The rich scent of grass and flowers helps to energize.