Thousands of years before scientists first identified L-theanine, ancient civilizations steeped green tea and Amazonian holly tree leaves. According to oral traditions around the globe, the elixirs heightened mental abilities and enhanced relaxation. Scientists discovered that the amino acid L-theanine was responsible for these positive health effects.


Scientific analysis conducted over the past 63 years has confirmed that L-theanine promotes cognitive performance and mental awareness. Unlike some other amino acids, L-theanine easily crosses the blood-brain barrier and rapidly enters the brain. This barrier is designed to protect the brain from harmful substances. Research indicates that L-theanine increases a protein in the hippocampus known as Brain Derived Neurotrophic Factor (BDNF). The hippocampus is a structure in the brain that is responsible for memory and learning. BDNF promotes a healthy environment for existing nerve cells and encourages the growth of new cells.

L-theanine’s molecular structure resembles glutamate, a biochemical messenger that is responsible for encoding memories. Glutamate promotes learning and memory by enhancing the transmission of messages between nerve cells. Researchers theorize that the structural similarity between L-theanine and glutamate is one of the reasons for L-theanine’s positive effects. The structural similarities also enable L-theanine to help the body maintain safe levels of glutamate. Excess glutamate levels can damage and kill cells in the nervous system. Because L-theanine resembles glutamate, it can occupy glutamate receptors and prevent the body from releasing excess glutamate. According to numerous studies, elevated glutamate is a major reason for the cognitive impairment that occurs with dementia.

L-theanine also improves cognitive performance by reducing anxiety. It increases serotonin, dopamine and GABA levels. These biochemical messengers create a sense of wellbeing and promote a normal mood. Dopamine is also noteworthy for its positive effect on attention and memory. Electroencephalographic studies provide a visual illustration of L-theanine’s ability to calm the brain without causing drowsiness. L-theanine increases the presence of Alpha waves. These bands indicate that a person is awake and relaxed. Researchers who analyze the effects of L-theanine often incorporate caffeine in their studies because the two substances coexist in nature. L-theanine balances the stimulating effects of caffeine without canceling its ability to promote mental energy.

In December 2010, scientists reported the effects of L-theanine on cognitive performance in the journal Nutritional Neuroscience. Forty-four young adults were assigned to receive L-theanine with caffeine or a placebo, which is an inactive ingredient. According to the study, the L-theanine-caffeine group demonstrated a significant improvement in their ability to perform cognitive tasks. The participants also reported an increase in mental awareness and a decrease in exhaustion levels.

A study published in the April 2011 issue of the Journal of Medicinal Food assessed the cognitive effects of L-theanine in participants with mild impairments. The 91 volunteers were assigned to receive L-theanine and a green tea extract or a placebo. The L-theanine-tea group experienced a significant improvement in their attention and memory. There was no measureable improvement in the placebo group.

In the August 2011 issue of Pharmacological Research, scientists evaluated the effect of L-theanine on elderly participants with normal cognitive function or mild impairments. The investigators randomly assigned participants to receive L-theanine or a placebo. The L-theanine group experienced a significant reduction in the rate of cognitive decline. The investigators concluded that L-theanine has a beneficial effect on cognition in the elderly.

Doxiderol is an excellent way to enjoy the benefits of L-theanine. This holistic supplement promotes focus, energy and concentration. L-theanine is one of the high quality ingredients specially chosen for its ability to support brain health and cognitive function. Doxiderol’s unique proprietary blend also features caffeine for its incredible health benefits.