L-Theanine is a versatile single-ingredient nootropic and adaptogen. Found naturally in the leaves of teas all over the world, L-Theanine has been ingested for centuries. L-theanine was discovered as a constituent of green tea in 1949 and was approved in Japan in 1964 for unlimited use in all foods. As a result, it is incredibly safe to ingest and gives foods and drinks a unique umami taste and flavor.

This nootropic has become very well known for it’s effects on stress in the human body. L-theanine may help relieve stress by inducing a relaxing effect without drowsiness and may also possess immunologic attributes. Theanine may also have effects on the cardiovascular system and play a preventative role in cancer. Theanine is also well known and researched to improve the levels of the GABA neurotransmitter in the brain. By increasing the GABA in the brain, this herb is able to help provide a balance between the GABA neurotransmitter and glutamate. GABA is the “downer” neurotransmitter that counters the “upper,” glutamate.

Interestingly, the relaxing and attention promoting properties of L-theanine combined with the lack of sedation gives L-Theanine its most significant supplemental role in reducing the ‘edge’ of many stimulants. A combination of L-Theanine with caffeine (200mg each) is noted to be synergistic in promoting cognition and attention.

L-Theanine is a commonly used nootropic for it’s calming effect. As a result, many nootropic stack creators include this ingredient to help reduce some of the effects of more stimulating compounds. As mentioned above, Theanine has been proven to help reduce the negative effects of caffeine, such as jitters.

How Much L-Theanine Should I Take?

The standard dosage for L-Theanine is about 200mg taken alongside an equal or lesser dose of caffeine. There do not seem to be any severe effects from taking higher dosages. However, no significant increases are noticed at the higher dosage either.

Is It Safe?

This nootropic is incredibly safe to ingest. It’s been used for thousands of years in teas, tonics, and tinctures with great results. No serious side effects are experienced when taking this nootropic as a healthy individual.

Our Take

L-Theanine is a great supplement to add to a nootropic stack. While on its own, no significant effects are felt, this nootropic is very effective in a stack. There are few to no negative side effects or interactions making this a very safe herb to work with. If buying this as a single ingredient, consider coupling it with a source of caffeine. We’ve also reviewed many stacks containing L-Theanine that have significant nootropic effects.