Literally translated as ‘vigor,’ ojas is the essential energy of the immune system. There isn’t an exact correlation for ojas in Western medicine. Truly, the meaning of ojas encompasses many things. Ayurvedic practitioner, author and chef Kate O’Donnell describes ojas as “the subtle essence of our life energy”. In some ways this vital essence can be considered the eighth dhatu (bodily tissue), but it is not exactly a tissue. It is more refined and subtle than that. However, ojas can only be built after all the seven dhatus are nourished.