Oolong Teas are indeed extraordinary because they span an oxidation range of 20-80%, where some are closer to green teas, and others are more similar to black teas. Caffeine levels vary accordingly, where greener oolongs will have less caffeine content and darker oolongs will have higher caffeine content. Oolong teas, because they have higher oxidation levels than green tea, will also have lower catechin levels, although catechins are still present.

However, although catechins decrease with oxidation, theaflavin and thearubigin levels increase. These polyphenols help in defending the body against stroke, dementia, heart disease and cancer. In addition to this, oolong teas have long been believed to aid in digestion, so enjoy a cup with or after your next meal.