L-Theanine is a soothing amino acid found in green tea and Bay bolete mushroom.

Structurally similar to neurotransmitters l-glutamine and l-glutamate, L-Theanine is one of the few supplements known to modulate alpha brain waves. Which are associated with calm focus, wakeful relaxation and creative thinking.

It’s often combined with caffeine to smoothen the negative side effects of the drug – such as jitters and energy crashes.

L-Theanine is also one of the best natural female vitality enhancers, due to its safety and a variety of beneficial effects on the body and mind.

Physical Effects

  • Lowers blood pressure
  • Eases restlessness
  • Bolsters immunity

Mental Effects

  • Improves sleep quality
  • Deepens focus
  • Promotes ‘out of the box’ thinking
  • Protects brain cells from glutamate overactivity
  • Calms anxiety without sedation

How L-Theanine Works

In the Body

  1. Lowers cortisol, anxiety and blood pressure

L-Theanine works on your brain’s alpha waves, which are responsible for inducing feelings of peace, calm and deep focus (without making you sleepy).

This is different than the state that we’re in most of the time, which is the ‘beta’ brainwave state. This is linked with excitation, alertness, and even stress.

Chronic stress means our cortisol levels stay elevated, which can bring about a whole host of health issues down the road.

By enhancing alpha brain waves, L-Theanine has a direct effect on cortisol – reducing the overproduction of the stress hormone.

This is supported by studies that report a reduction in salivary stress markers following l-theanine consumption. [1, 2]

What’s more, clinical trials have shown that L-Theanine helps reduce heart rate and blood pressure in people with anxiety.

  1. Supports the immune system

As we previously mentioned, high cortisol has many negative implications on the body.

One of them is that it increases your neutrophils while decreasing your lymphocytes, suppressing your immune system and creating inflammation in the process.

L-theanine has been shown to revert these effects, both alone and when combined with L-cystine. It strengthens the immune system and reduces the risk of catching a cold or the flu.

What’s more, L-Theanine can boost the activity of your killer T cells, which protect the body against cancer and infections. [3, 4]

  1. Lowers sugar and fat absorption in the gut (boosting weight loss)

One benefit of L-Theanine not many people know about is that it may boost weight loss.

It achieves this in different ways. One, it’s been shown to reduce triglyceride and fatty acids in the blood. [5]

Secondly, L-theanine directly lowers food intake and body weight.

Last but not least, one animal study showed that it reduces the uptake of fats and sugars in the gut. This is part of the reason why green tea is so effective at boosting fat loss and preventing weight gain. [6]

In the Brain

  1. Modulates brainwave activity

L-Theanine reduces mental stress by increasing alpha brain waves. Alpha waves are linked to relaxation and concentration. The effect is similar to that of meditation.

In one study from South Korea, 20 healthy male participants between 18-30 years old were split into a L-Theanine and a placebo group.

The trial lasted 7 days. The researchers measured participants’ brain waves 40 minutes after giving them either L-Theanine or placebo tablets.

They found that L-Theanine tablets boosted the activity of alpha brain waves related to cognitive focus and relaxation. [7]

  1. L-Theanine boosts neurotransmitters.

L-theanine does more than just affect your brain waves. According to research, it also increases your serotonin, dopamine and GABA neurotransmitters.

At the same time, it reduces glutamate, the excitatory neurotransmitters linked to stress, tension and brain cell death.

One study from Japan looked into the effects of L-theanine in 12 people across 4 separate trials. In one trial, these people took L-Theanine at the beginning of the test. In another one, they took it half-way through the trial. In the last two trials, the participants either took a placebo or nothing.

The results of this exhaustive study showed a reduction in heart rate and s-IgA, both of which are associated with acute stress.

The study concluded that L-theanine has the potential to lower stress by inhibiting the ‘overexcitation’ of cortical neurons. [8]

L-Theanine and Female Vitality

L-theanine can help almost anyone feel more at ease, but studies show it may be the most effective for females dealing with high levels of anxiety.

Five different studies with a combined 104 volunteers found that L-theanine lowered stress and anxiety in those who were going through stressful situations.

Another randomized-controlled trial reported increased relaxation and reduced resting heart rate, without causing drowsiness. [9]

L-theanine may even help with other, more serious conditions. In a study published in the Journal of Clinical Psychiatry, researchers found that L-theanine not only lowered anxiety but also improved symptoms of schizophrenia. [10]

Another clinical trial looked into L-theanine’s effects on depression. The study included 20 people with major depressive disorder, and found that L-theanine could help with depressive symptoms, sleep impairments, and cognitive dysfunction. [11]

Other benefits of L-theanine for female vitality include:

  • Improved mental state during stress
  • Lowered Inflammation
  • Reduced stomach ulcers

The Science

Here’s a look at some of the L-theanine studies and how the compound may improve female vitality and health overall.

Study #1: L-Theanine Lowers Stress

A lot of research has been done on L-theanine and its effects on stress in both animal and human trials.

The thing about stress is that it negatively affects almost every aspect of health – including your memory and focus.

Corticosteroids, which secrete when you’re stressed, have a massive long-term impact on memory formation and potentiation.

In one animal study, mice were fed L-theanine-containing water for 3 weeks. After this, they were put through a stress-inducing exercise. The results showed lower stress levels in mice who took L-theanine than those who had none.

More impressively, the stress that L-theanine fed mice did experience didn’t have any effect on them. Their memory wasn’t affected.

The study concluded that L-theanine modifies corticosterone release. Thanks to this effect, it can be a strong preventative measure in preventing memory loss caused by stress. [12]

Study #2: Green Tea May Protect the Brain from Stroke

Studies suggest that if L-theanine is present in the body at the time of stroke, the brain suffers much less damage.

One massive study from China took this a step further. It looked at 14,212 subjects across 12 provinces. Their ages ranged between 35-60 years old.

The researchers looked at the subject’s tea drinking status, type of tea they were drinking, and the dose.

They ultimately found that the people who drank green, black or jasmine teas had a 40% lower risk of stroke. [13]

Study #3: L-Theanine Improves Memory

This double-blind, placebo-controlled study looked at the effects of L-theanine on attention and memory.

The researchers recruited 91 subjects with mild cognitive dysfunction. One group took 1,680mg of L-theanine every day for the next 3 weeks, while the control group took a placebo pill.

At the end of the trial, the results showed an increase in brain Theta waves linked to cognitive alertness and creativity. What’s more, L-theanine improved these people’s memory.

Based on these findings, the researchers concluded that L-theanine has the potential to improve markers of cognitive impairment. [14]

You could say that this is an understatement, and we wouldn’t blame you. People meditate for years to be able to consistently enter a theta brainwave state. In this study, people achieved the same with a dose of L-theanine. The same one you could get from a few cups of good quality green tea.

Study #4: L-Theanine Boosts Sleep Quality

Here we’ll actually be looking at multiple studies that investigate L-theanine’s benefits on sleep.

A considerable amount of research shows that green tea with high L-theanine and low caffeine content can improve sleep quality and reduce anxiety in middle-aged women. [15, 16, 17]

L-theanine also helps soothe sleep disturbances caused by certain conditions. It’s been shown to improve sleep quality in everyone from boys with ADHD, adults with major depressive disorder, and individuals with schizophrenia. [18, 19, 20]

Animal studies show similar results. In one particular trial, mice that were given a combo of L-theanine and GABA saw an improvement in both duration and quality of their sleep. [21]

In another study, L-theanine canceled the negative effects of caffeine on sleep.

This brings us to the next question; are there any benefits to mixing caffeine and L-theanine?

L-Theanine and Caffeine: Can You Mix Them Together?

Caffeine and L-theanine are naturally found in green tea. L-theanine works to enhance caffeine’s positive effects (mental focus, energy, alertness, mood) whilst reducing its harsh side effects (increased blood pressure, jitters, anxiety).

This is supported by studies which show that L-theanine+caffeine combo works better than either one of them alone. Specifically, the combo might be superior at improving memory and brain function. [22]

Kurapeak contains clinically researched 100mg of L-theanine per serving. Taking it together with your morning coffee is a perfect way to reap the energizing benefits of both compounds, while also smoothening out caffeine’s negative effects.

Optimal Dosage

L-Theanine is typically taken in doses between 100-400mg per day. Although the safe upper limit is 1,200mg, this compound works best when taken in lighter doses, especially over the long-term.

Which is precisely why we’ve included 100mg of L-theanine in Kurapeak. Even though it’s plenty and enough to experience all of its benefits, it also means you won’t build a tolerance to it as you’d do with a higher dosage.

L-Theanine is water soluble and so it can be taken without food.

Safety of L-Theanine

As a naturally occurring amino acid, L-theanine is perfectly safe and non-toxic. It does decrease blood pressure, which means you should talk to your doctor prior to taking it if you’re on a blood pressure-lowering medication.

How Does it Feel to Use L-Theanine Daily?

Every person has different neurochemistry, brain waves, and brain structure. L-theanine might not work for you the same way it does for someone else.

That being said, most people who take L-theanine report a calming effect after about 45 minutes of ingestion. You may notice your cognition getting a boost, and your energy levels rise without the typical jitters of caffeine.

If you have issues with anxiety and nervousness, L-theanine can help tremendously in this case. Its alpha-wave, GABA-boosting activity means it’s one of the most effective natural calming agents, without actually sedating you (unlike benzo for example).

Most people who take L-theanine report an improvement in their overall life quality. And almost everyone says they sleep sounder.

Kurapeak Stack Strategy: L-Theanine + Coffee (or Your Other Favorite Source of Caffeine) for Clean Mental Energy

Kurapeak is stim-free. Part of the reason why is because most people already drink caffeinated beverages to boost their alertness throughout the day.

Kurapeak’s L-theanine works as an enhancement to caffeine. It delivers L-Theanine in a stim-free formula, allowing you for more precise control over your daily stimulant intake.

References

  1. White DJ, de Klerk S, Woods W, Gondalia S, Noonan C, Scholey AB. Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial. Nutrients. 2016;8(1):53. Published 2016 Jan 19. doi:10.3390/nu8010053
  2. Unno K, Tanida N, Ishii N, et al. Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary α-amylase activity, trait anxiety and subjective stress. Pharmacol Biochem Behav. 2013;111:128-135. doi:10.1016/j.pbb.2013.09.004
  3. Kamath AB, Wang L, Das H, Li L, Reinhold VN, Bukowski JF. Antigens in tea-beverage prime human Vgamma 2Vdelta 2 T cells in vitro and in vivo for memory and nonmemory antibacterial cytokine responses. Proc Natl Acad Sci U S A. 2003;100(10):6009-6014. doi:10.1073/pnas.1035603100
  4. Bukowski JF, Percival SS. L-theanine intervention enhances human gammadeltaT lymphocyte function. Nutr Rev. 2008;66(2):96-102. doi:10.1111/j.1753-4887.2007.00013.x
  5. Zheng G, Sayama K, Okubo T, Juneja LR, Oguni I. Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice. In Vivo. 2004;18(1):55-62.
  6. Yan Q, Tong H, Tang S, Tan Z, Han X, Zhou C. L-Theanine Administration Modulates the Absorption of Dietary Nutrients and Expression of Transporters and Receptors in the Intestinal Mucosa of Rats. Biomed Res Int. 2017;2017:9747256. doi:10.1155/2017/9747256
  7. Song CH, Jung JH, Oh JS, Kim KS. Effects of Theanine on the Release of Brain Alpha Wave in Adult Males. Korean J Nutr.  2003 Nov;36(9):918-923.
  8. Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007;74(1):39-45. doi:10.1016/j.biopsycho.2006.06.006
  9. Williams, Jackson & Kellett, Jane & Roach, Paul & Mckune, Andrew & Mellor, Duane & Thomas, Jackson & Naumovski, Nenad. (2016). L-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. Beverages. 2. 10.3390/beverages2020013.
  10. Michael S. Ritsner, MD, PhD; Chanoch Miodownik, MD; Yael Ratner, MD; Tatyana Shleifer, MD; Maria Mar, MD; Leonid Pintov, MD; and Vladimir Lerner, MD, PhD. L-Theanine Relieves Positive, Activation, and Anxiety Symptoms in Patients With Schizophrenia and Schizoaffective Disorder: An 8-Week, Randomized, Double-Blind, Placebo-Controlled, 2-Center Study. J Clin Psychiatry 2011;72(1):34-42
  11. Hidese S, Ota M, Wakabayashi C, et al. Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr. 2017;29(2):72-79. doi:10.1017/neu.2016.33
  12. Tamano H, Fukura K, Suzuki M, Sakamoto K, Yokogoshi H, Takeda A. Preventive effect of theanine intake on stress-induced impairments of hippocamapal long-term potentiation and recognition memory. Brain Res Bull. 2013;95:1-6. doi:10.1016/j.brainresbull.2013.02.005
  13. Chen Z, Li Y, Zhao LC, et al. Zhonghua Liu Xing Bing Xue Za Zhi. 2004;25(8):666-670.
  14. Park SK, Jung IC, Lee WK, et al. A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study. J Med Food. 2011;14(4):334-343. doi:10.1089/jmf.2009.1374
  15. Unno K, Noda S, Kawasaki Y, et al. Reduced Stress and Improved Sleep Quality Caused by Green Tea Are Associated with a Reduced Caffeine Content. Nutrients. 2017;9(7):777. Published 2017 Jul 19. doi:10.3390/nu9070777
  16. Hidese S, Ogawa S, Ota M, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019;11(10):2362. Published 2019 Oct 3. doi:10.3390/nu11102362
  17. Unno K, Noda S, Kawasaki Y, et al. Ingestion of green tea with lowered caffeine improves sleep quality of the elderly via suppression of stress. J Clin Biochem Nutr. 2017;61(3):210-216. doi:10.3164/jcbn.17-6
  18. Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16(4):348-354.
  19. Hidese S, Ota M, Wakabayashi C, et al. Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr. 2017;29(2):72-79. doi:10.1017/neu.2016.33
  20. Ota M, Wakabayashi C, Sato N, et al. Effect of L-theanine on glutamatergic function in patients with schizophrenia. Acta Neuropsychiatr. 2015;27(5):291-296. doi:10.1017/neu.2015.22
  21. Kim S, Jo K, Hong KB, Han SH, Suh HJ. GABA and l-theanine mixture decreases sleep latency and improves NREM sleep. Pharm Biol. 2019;57(1):65-73. doi:10.1080/13880209.2018.1557698
  22. Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008;11(4):193-198. doi:10.1179/147683008X301513

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