theophylline

Tea is an aromatic beverage commonly prepared by pouring hot or boiling water over cured leaves of the tea plant, Camellia sinensis. After water, tea is the most widely consumed beverage in the world. It has a cooling, slightly bitter, and astringent flavour that many people enjoy.

Guarana is a climbing plant in the family Sapindaceae, native to the Amazon basin and especially common in Brazil.Guarana has large leaves and clusters of flowers and is best known for the seeds from its fruit, which are about the size of a coffee bean.It contains about twice the concentration of caffeine found in coffee seeds. The additive has gained notoriety for being used in energy drinks.The colour of the fruit ranges from brown to red and it contains black seeds that are partly covered by white arils.