It is called dragon’s black tea or oolong blue tea , and is ideal as a tea for weight loss: this special infusion with a slightly blue color can in fact be an excellent adjuvant in the diet. There are 5 benefits for weight loss of this variety of tea, which can help us lose weight especially in the abdominal area and that we can drink hot, lukewarm or cold.
In fact , Oolong blue tea contains a higher concentration of a strongly antioxidant substance that is the basis of the use of tea for weight loss, namely Epigallocatechin gallate ,a polyphenol much more powerful against free radicals than vitamins C and E, known for their antioxidant value. This substance improves metabolism and causes the body to burn more calories. It also has a higher concentration of tianine , a vitamin (B1) useful for converting the glucose of carbohydrates into energy. Therefore, if our diet is balanced and Mediterranean-type, i.e. we also consume fruit and cereals, this tea allows us to burn carbohydrates more easily.
According to a study that appeared in the Journal of Obesity, blue tea, an aged variety of fermented oolong tea, promotes abdominal fat loss and cleanses the liver. 
Finally, it would bealso a valid help to counteract bad cholesterol and improve the good intestinal flora thanks to the compounds derived from its fermentation. Here is a link where to buy it.

In short: Oolong blue tea is confirmed as one of the most popular teas for weight loss! We can drink two to three cups a day if we want to increase our chances of losing weight.

Insights : The 5 Best Teas For Weight Loss.