Oolong tea is a product made from the leaves, buds, and stems of the Camellia sinensis plant. This is the same plant that is also used to make black tea and green tea. The difference is in the processing. Oolong tea is partially fermented, black tea is fully fermented, and green tea is unfermented. It reduces the absorption of fat content from high-cholesterol meals and raises metabolism. It helps break down bacteria and eliminate toxins from your body. Mental alertness and focus have been known to be enhanced as well.