Caffeine is an alkaloid from the xanthine group. It can be found in over 60 plants, including the coffee plant, the tea bush, guarana, mate, and cola nut. Thanks to its stimulating effect on the brain and its ability to enhance motivation and concentration, caffeine is the most popular stimulant in the world.
L-theanine is an amino acid similar to glutamine that occurs naturally almost exclusively in the green tea plant (Camellia sinensis). L-theanine has antioxidative properties and can protect healthy cells against oxidative stress. L-theanine can also help to regulate various neurotransmitter systems and can have a relaxing effect.
Combining caffeine with L-theanine can enhance caffeine's concentration-boosting and stimulating effects, while minimising negative side effects such as uneasiness and nervousness.