Oolong tea, also known as green tea, is a semi-fermented tea, and does not have the effect of medicine, but only provides energy to the body by replenishing the body with nutrients such as tea polyphenols and theobromine. Oolong tea is concocted through the procedures of killing, withering, shaking and semi-fermentation. Oolong tea contains tea polyphenols, theobromine, caffeine, phytochemicals, amino acids, proteins, organic acids, lipopolysaccharides, sugars, enzymes, vitamins, and many other organic chemical components. Since oolong tea is just a kind of tea, it does not have the effect of medicine, so it can only replenish the body with a small amount of nutrients needed after drinking, but its main role is to provide water. Since oolong tea contains caffeine, it can easily make people feel excited, so people with insomnia may aggravate their insomnia after drinking it. It is recommended that insomniacs try not to drink oolong tea, and go to the hospital if they feel unwell.