L-Theanine: The Calming Amino Acid

L-Theanine: The Calming Amino Acid

L-Theanine is an amino acid commonly found in black or green tea (camellia sinensis).  It is partly responsible for the teas mood enhancing benefits. L-Theanine boosts levels of various neurotransmitters, producing a calming effect that helps counter the stimulating action of caffeine. At the same time, there are many studies showing how L-Theanine works synergistic with caffeine to promote concentration, reduce the jitteriness of caffeine and generates a calm alertness.

As a result of the effects associated with L-Theanine, it is marketed as a supplement to help promote relaxation and reduce stress.

Most research on the basic actions of L-Theanine has been conducted in animal studies. However, preliminary human studies, typically using doses between 100mg – 500mg, have shown benefits and customers continue to mention the relaxing benefits noticed at these dosages anecdotally.

One study looked at college students who consumed L-Theanine experienced less anxiety and had smaller increases in blood pressure when under psychological or physical stress than when they took a placebo1. Similarly, another study found that graduate students who took L-Theanine experienced less anxiety when they were assigned stressful work, compared to a placebo2.

In a Canadian study, L-theanine improved some aspects of sleep quality in children with attention-deficit hyperactivity disorder (ADHD)3.

Based on the research and anecdotal reports L-Theanine has application in a number of products:

  • Stimulant based pre-workouts - and thermogenics may benefit from the clean energy extending effect L-Theanine has on caffeine. This benefit may prevent users from crashing, getting anxious or jitters from their product. L-Theanine may also enhance the feelings of extended energy, euphoria and appetite control. Of particular interest are studies showing that L-Theanine supplementation may prevent the abrupt rise in blood pressure that some people experience under stress (physically or emotionally)1. Furthermore, a recent study showed L-Theanine increases a signalling pathway called eNOS that increases Nitric Oxide, resulting in vasodilation rather than vasoconstriction during exercise5.
  • Night time or post workout recovery formulas - due to the calming effect of L-Theanine as it competes with the excitatory neurotransmitter (Glutamate), it is likely to pair well with Magnesium, Zinc and B6 to round out a calming ZMA style product. This is why L-Theanine helps relax the sympathetic (fight and flight) nervous system and engage the para sympathetic (rest and digest) nervous system.
  • Natural anti-anxiety products - can benefit from having L-Theanine added. Mounting research supports the anxiolytic (anti-anxiety) benefits of this tea compound. L-Theanine may work incredibly well when combined with Ashwaganda as this powerful adaptogenic herb works to lower stress and reduce panic and anxiety.
  • The Nootropic supplement - category is growing as people want to enhance or retain their brain power. L-Theanine has shown incredible promise in this space with the ability to protect the brain from age related decline and possibly enhance cognitive function, focus and alertness. L-Theanine benefits Alpha and Theta brain waves. This alone will help calm your mind, reduce stress, and help you stay alert. L-theanine helps boost neurotransmitters dopamine, serotonin and GABA, improving alertness and attention while boosting cognition and memory.


Summary: L-Theanine may be incredibly helpful at reducing stress, anxiety and panic (PTSD). It may also help you stay calm and alert. If used before or during training L-Theanine may enhance the benefits of caffeine and other stimulants while simultaneously increasing vasodilation and blood flow to your working muscles.

If used before bed or after a workout L-Theanine may help lower cortisol and minimise the impact that physical or mental stress is having on your recovery and rest. It may help support brain function, reduce age related mental decline and enhance cognition.

As a highly researched and naturally occurring amino acid, L-Theanine is worth consideration to help improve your performance and mental wellbeing.

Dosage: Suggested use is between 100mg – 500mg 1 to 3 times daily. If you are using it before bed less is more. Doses above 200mg may keep users too alert.

Disclaimer: The above article is merely a guide and is in no way a recommendation or a treatment protocol for any health conditions or diseases. You should always consult with a qualified health care provider before changing your supplement, training or nutritional strategy. Supplementation should not be attempted by pregnant or breastfeeding women, anyone on prescription medication or children under the age of 15 unless advised by your qualified health care provider.