L- Theanine has been heralded as one of the most revolutionary health care products in history, a game-changer for people who suffer from allergies and other respiratory diseases. The first-ever lysine-rich dry powder created by Nature’s Plus is now available to purchase online through its website at natureplususa dot com.


What is L-theanine and how does it work? L-theanine (also known as theanine or r-glutamylethylamide) is an amino acid that affects brain nerve impulses and neurotransmitter release, particularly GABA. It’s called a natural anxiolytic because it has a soothing, sedative impact on the body and mind without making you sleepy, which is why it’s often used to treat anxiety, hyperactivity, and sleep issues.

Because theanine isn’t found in many regularly consumed foods, most individuals don’t get enough of it from their diets. In addition, it’s an unusual amino acid because, unlike many other amino acids like l-carnitine, leucine, lysine, methionine, or tryptophan. Green, black, and white teas are the best sources of L-theanine in our diets, but since most people don’t consume a lot of tea on a regular basis, L-theanine supplements may help.

Drinking tea and taking L-theanine supplements may help lessen the impacts of stress, protect the brain, assist the cardiovascular system, and much more, as we’ll discuss more below.

What Is L-Theanine and How Does It Work?

L-theanine is classified as a nondietary, non-essential amino acid since, despite its advantages, it is not required in human diets.

What is the role of L-theanine in your body? It’s used to prevent and cure a variety of ailments, including:

  • Anxiety, sadness, and other mood disorders are common
  • Insomnia and sleeping problems
  • Alzheimer’s disease, dementia, and cognitive impairment
  • Stroke
  • Other cardiovascular issues, such as high blood pressure
  • Post-traumatic stress disorder (PTSD) is a kind of anxiety illness that occurs (PTSD)
  • Schizophrenia
  • Attention span issues
  • Dependency on drugs or alcohol
  • It might help boost the impact of cancer-fighting medications.

Although physically identical, the amino acids L-theanine and glutamine have distinct actions and advantages. Both may help with general mental health and energy levels, but theanine has the ability to serve as a natural stress reliever. Glutamine is the most prevalent amino acid in the circulation, accounting for 30 to 35 percent of the amino acid nitrogen in your blood.

Glutamine is required for the production of glutamate, a neurotransmitter. Although glutamate is an excitatory neurotransmitter, L-theanine binds to the same brain receptors as glutamate and hence has the opposite, inhibitory effect.

Is there a difference between L-theanine and caffeine? No, they’re not the same thing, despite the fact that they’re both present in drinks, including green tea. Caffeine and L-theanine have opposing but complimentary effects because L-theanine promotes relaxation while caffeine enhances attentiveness. However, studies show that when taken correctly, both L-theanine and caffeine may have positive impacts on cognition and mood.


What are the advantages of taking L-theanine? Here are five ways it may help with sleep, mental health, cognition, and other things.

1. Can Assist in Relieving Anxiety and Reducing Stress

The potential of L-theanine to induce relaxation and combat stress is one of the most well-studied of its advantages. It’s described as “a calming agent without generating sedation,” which means it may help you cope with stress without making you feel drowsy or weary.

If you experience uneasiness, anxiety, depression, or other stress-related difficulties, you may benefit from L-soothing theanine’s effects, but it won’t likely be powerful enough to alleviate severe anxiety. L-theanine was shown to lower scores on a tension-anxiety test when compared to placebo in one research. The effects of L-theanine and caffeine on mental task performance and physiological activity have been studied. Participants were given either L-theanine Plus placebo, caffeine + placebo, or placebo just while they were put under physical or psychological stress. After the mental exercises, the results revealed that L-theanine considerably reduced the blood pressure rise associated with stress, while coffee had a comparable but lower effect.

What does L-theanine do to your brain in order to help you relax? L-theanine possesses anti-stress properties because it suppresses (blocks) cortical neuron excitation. Theanine has been shown to pass the blood-brain barrier, particularly when given as an injection, and may boost brain concentrations of the substance for up to five hours when taken orally. The amygdala and hippocampus, two crucial parts of the brain that assist govern fear reactions and memory, seem to be affected by theanine.

Theanine may also boost alpha brain waves (-waves), which are linked to “wakeful relaxation,” selective attention processes, arousal, and mental acuity. One research looked at the effects of 50 milligrams of L-theanine on brain waves 45, 60, 75, 90, and 105 minutes after intake. In comparison to the placebo condition, the L-theanine condition exhibited a higher rise in alpha activity over time. “These findings show that L-theanine, at actual dietary quantities, has a considerable influence on the overall state of mental alertness or arousal,” the study’s authors write. Furthermore, since the alpha activity is known to play a key role in vital areas of attention, further study is being conducted to better understand the effects of L-theanine on attentional processes.”

2. Can Help You Sleep Better and Fight Insomnia

Why is L-theanine beneficial to sleep? Mostly because it aids in the reduction of tension and anxiety, which might keep you awake at night if you’re continuously worried and tossing and turning. Because theanine’s effects on sleep are moderate, it won’t help everyone enhance their sleep quality. While it may improve sleep quality, it is unlikely to be sufficient to enable someone with moderate or severe insomnia to achieve a decent night’s sleep.

L-theanine has been shown in several trials to enhance sleep quality in persons with hyperactive disorders, such as ADHD. Another advantage of L-theanine for sleeping is that it may counteract the effects of stimulants. This implies that whether you consume a lot of coffee or take other stimulants for medical reasons, the calming effects of L-theanine may help you sleep better and feel less jittery.

Some individuals combine L-theanine and melatonin to help them sleep better. Before going to bed, take roughly three grams of melatonin with 100–200 mg of L-theanine. Although L-theanine given in excessive dosages (more than 600 mg) may have the opposite effect, the two may work together to lower stress and improve sleep quality.

3. It has the potential to improve attention

In order to boost alertness, cognition, and attention, some individuals combine L-theanine with caffeine. The two have a “synergistic” link that may help you concentrate without feeling nervous or “wired.” The greatest outcomes are obtained by taking around 200 milligrams of L-theanine plus caffeine.

4. Can Assist in Memory and Cognition Protection

Patients with moderate cognitive impairment were administered 360 milligrams of green tea extract and 60 milligrams of theanine (a combination named LGNC-07) three times a day for 16 weeks in a double-blind, placebo-controlled research. LGNC-07 improved recognition abilities while having no detrimental impacts on verbal or visuospatial memory, according to the researchers.“Brain theta waves, a measure of cognitive alertness, were enhanced considerably in the temporal, frontal, parietal, and occipital regions after three hours in the eye-open and reading phases,” according to the study’s authors. As a result, our research implies that LGNC-07 might be used as a cognitive-improvement intervention.”

Excess glutamate stimulation of brain cells (excitotoxicity), which some think is connected to neurodegenerative illnesses, stroke, and schizophrenia, is one method L-theanine may aid in protecting the brain. L-theanine may provide neuroprotection for the aging brain by suppressing some of the glutamate’s effects.

5. It’s possible that it may help with cardiovascular health

Green tea is the most abundant source of L-theanine, and several studies have shown that it may help decrease inflammation and improve heart health. Some specialists think that theanine, rather than other active chemicals like green tea catechins or theaflavins, is responsible for green tea’s cardiovascular health benefits.

Theanine may assist control nitric oxide and reduce blood pressure increases in reaction to stressful circumstances. Nitric oxide is a chemical produced by our bodies to aid cell communication, control blood pressure through dilation of arteries, decrease inflammation, boost the immune system, and enhance sleep quality, among other things. Nitric oxide is produced by the endothelial layer of our arteries, which helps to relax restricted blood vessels and improve oxygen and blood flow. Nitric oxide production that is enough may assist in guarding against clots or blockages in arteries, heart attacks, strokes, and other cardiovascular issues.

Some studies have also shown that administering L-theanine after a stroke, preferably within 12 hours but possibly up to 24 hours later, may help preserve brain cells and minimize stroke damage.

Theanine supplementation has also been found in experiments on roundworms (the species C. elagans) to aid enhance life span and improve longevity. Roundworms exposed to high quantities of L-theanine had their life spans prolonged by an average of 3.6 percent and up to 4.4 percent. In addition, researchers discovered that a dose on the low end of the spectrum was the most helpful when it came to lifespan.


Is L-theanine a natural substance? Green tea (produced from the leaves of the camellia sinensis plant) is one of the meals and drinks that contain it. L-theanine is one of the key active compounds in green tea and caffeine, and catechins. Theanine is thought to give green tea its subtle umami flavor and help balance the bitterness of green and black teas and other bitter foods like chocolate.

Green tea contains how much L-theanine? It accounts for up to half of the total amino acids in tea. Theanine makes from between 0.9 percent to 3.1 percent of the dry weight of green tea leaves. This translates to 25 to 60 milligrams of theanine per 200 milliliters (6.7 ounces) of tea. Approximately 2.5 grams of dried tea leaves are used to make this quantity of tea. Green tea’s theanine concentration varies depending on the variety of tea. Theanine concentration is greater in teas prepared from younger plants than in teas made from older plants. Fermentation (a step in the tea-making process) reduces theanine concentration, but it becomes more concentrated as the leaves are dried.

What additional foods include L-theanine? Although much study has focused on theanine from green tea leaves, it may also be present in leaves used to make black and white teas. L-theanine is also found in the following plants:

  • C. japonica and C. sasanqua are two tiny shrubs with pink and scarlet blooms. They are sometimes used to brew tea, although not as often as Camellia sinensis.
  • Xerocomus badius, sometimes known as bay bolete, is a brown, edible, pored fungus that may be found throughout Europe and North America.


Is L-theanine a safe supplement? According to research, it is safest when taken for a short period of time, such as a few weeks to four months. It is usually given once a day for three to sixteen weeks by mouth. It’s unclear if it’s always safe or effective when used for prolonged periods of time.

What is the maximum amount of L-theanine that may be consumed safely? Most individuals may comfortably take up to 200 mg per day (divided into two or three doses), while greater dosages of up to 400 milligrams have been used successfully as well.

Certain medicines, such as those used to treat high blood pressure (antihypertensive drugs) and stimulants, may interact with L-theanine. Because theanine may drop blood pressure, don’t take it without first seeing your doctor if you’re currently using blood pressure drugs. Atropine (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), and diltiazem are some examples of blood pressure drugs (Cardizem).

Because theanine may slow down nervous system activity, it will interfere with the effects of stimulants (including foods/drinks and drugs). If you’re using a stimulant like diethylpropion (Tenuate), epinephrine, phentermine (Ionamin), or pseudoephedrine (Sudafed), see your doctor before taking L-theanine. L-theanine may reduce the stimulating effects of caffeine and some herbs, such as coffee, tea, green tea extract, gurana, yerba mate, cola and other caffeinated sodas, and energy drinks, which is a positive thing.

Because there hasn’t been much study done on the safety of L-theanine supplementation during pregnancy, it’s advised to avoid it for pregnant women (although drinking one to two cups of green tea during pregnancy is considered safe for most women).

GABA vs. L-theanine

  • L-theanine may aid in the creation of GABA, an inhibitory and calming neurotransmitter.
  • GABA is a neurotransmitter, much as serotonin and dopamine. It aids in the regulation of emotions, moods, focus, motivation, and alertness. GABA has an impact on sleep, hunger, and sexual desire.
  • GABA is recognized for its soothing and anti-anxiety properties, making it useful for improving mood and avoiding anxiousness and hyperactivity. L-theanine exerts calming effects in part via boosting GABA levels. L-theanine may assist to alleviate depression symptoms such as exhaustion, changes in appetite, sleeplessness, and a lack of desire by increasing GABA levels.
  • Some anti-anxiety drugs operate by simulating GABA’s effects, although they’re often accompanied with sleepiness. L-appeal theanine’s as a relaxing agent stems from the fact that it does not impair motor abilities or cause fatigue. In fact, it can both boost attentiveness and encourage relaxation.
  • Theanine injections have been shown to boost GABA concentrations in the brain, occasionally by up to 20% when administered in large dosages. Moderate amounts of theanine are likely to have a little influence on GABA levels, but it may be enough to make a difference in your mood.


In 1949, Japanese scientists discovered L-theanine in tea leaves for the first time. One of the original reasons scientists looked at theanine was that it was thought to be a source of umami, a savory, brothy flavor found exclusively in particular foods such as meat, fish, mushrooms, and certain vegetables. Researchers think that umami flavor affects the brain in a manner that helps to reduce obesity risk, promotes metabolism, changes the taste perception of bitter foods, increases satiety and fullness, and keeps hunger and cravings at bay between meals.

Green tea, the finest source of theanine, is valued in Ayurvedic medicine for its strong antioxidant content, although the caffeine in green tea is not suggested for everyone. Green tea is a better alternative than coffee and other stimulants since it contains less caffeine, particularly for Vata and Pita types who already suffer from restlessness and anxiety. Green tea is also regarded as a restorative beverage in Ayurveda since it may assist to counteract the effects of stimulants and stress. This is particularly true when green tea is combined with herbs and spices to achieve doshic equilibrium. Many tea variations are used in the Ayurvedic diet because each variety has specific characteristics, such as:

  • Green jasmine tea, which has a sedative impact on the nervous system.
  • Moroccan mint green tea, which may aid with nausea and digestive problems.
  • Bancha tea is an expensive tea that is high in catechins.
  • Green tea with ginger is good for the immunological and digestive systems.
  • Cinnamon green tea is anti-inflammatory.
  • Genmaicha tea is a warming and energetic beverage.
  • Matcha tea includes a high concentration of L-thianine.

Green tea has been drank for thousands of years in China and other regions of Asia. Tea is the most beneficial of all herbs, according to Traditional Chinese Medicine (TCM), and has several advantages, including enhancing alertness, strengthening immunity, regulating bodily fluid production, satisfying thirst, eliminating heat and phlegm, and encouraging good digestion and urine. The quantity of green tea advised in TCM varies depending on the ailment being treated. Green tea is typically consumed in three cups (750 milliliters) each day, but up to ten cups (2,500 milliliters) may be effective in the treatment of some health disorders. While green tea is the most useful in TCM, several other varieties of teas, such as white, black, and oolong teas, are also recommended.

Supplements and Dosage

Because L-theanine is almost solely found in tea leaves, it might be difficult to get enough of it from meals and beverages to perceive its benefits. This is why L-theanine is sold as a supplement. L-theanine, the bioavailable supplement form of the amino acid theanine, is the most common type of theanine supplement. Suntheanine is a proprietary fermentation process-made theanine supplement. While makers of suntheanine say that it is more effective, there does not seem to be much of a difference in efficacy or tolerance between L-theanine and suntheanine.

Where to Get It and How to Use It

Supplements containing theanine exist in a variety of formats, including capsules, pills, and tablets. Always verify the supplement formula’s components to guarantee you’re getting a good product. Purchase a supplement that contains just theanine/L-theanine and no additional chemicals or fillers. Keep in mind that certain energetic theanine solutions may include caffeine, which isn’t good for decreasing anxiety or aiding sleep.

  • L-theanine is usually given at daily doses of 100–200 mg. It may be taken with caffeine, but it isn’t required.
  • L-soothing theanine’s effects are normally seen within 30–60 minutes after consuming it.
  • Doses of 200 mg administered twice day are typically the most effective for treating sleeplessness, ADHD, and hyperactivity.
  • Higher dosages of L-theanine, about 400 milligrams, may be used to assist people with schizophrenia or severe anxiety disorders control their symptoms. This dosage may be repeated up to eight times.
  • A combination of L-theanine (400 mg per day) and the hormone pregnenolone (50 mg per day) is occasionally used to aid with anxiety.

Is L-theanine safe to consume on an empty stomach? Yes, you may take L-theanine with food or on an empty stomach. However, you may experience the benefits of L-theanine more rapidly and powerfully if you haven’t eaten lately (similar to consuming coffee with a meal vs. on an empty stomach). Take L-theanine 30–60 minutes before bedtime if you’re using it to help you sleep.


Consuming high-quality green tea and other black or white teas is the greatest method to get L-theanine. Green tea is thought to be the richest source of theanine and hence the best method to boost your consumption, particularly since it also contains catechin antioxidants (such as epicatechin, epigallocatechin, and gallocatechin) and EGCG (epigallocatechin-3-gallate). For the best anti-aging effects, most experts suggest drinking three to four cups of unsweetened green tea every day, although one to two cups is still a healthy supplement to your diet. To make green tea, follow these steps:

  1. In your teapot, place your tea bag or high-quality tea leaves (for the finest tea, choose organic from a respected manufacturer).
  2. Heat or boil the water, but do not allow it to boil entirely or get too hot since this can damage some of the delicate components in green tea leaves. Green tea should be brewed at a temperature of 160 degrees Fahrenheit to 180 degrees Fahrenheit (traditionally, normal Chinese green teas are brewed at somewhat higher temperatures). Fill the teapot halfway with boiling water and steep the leaves for 1–3 minutes. Larger leaves take longer to steep than smaller, finer ones. You may also add any fresh herbs you want to soak at this stage.
  3. Once the tea is made, pour a little amount of tea into each cup at a time to equally spread the tea’s strength. As a final touch, squeeze in some lemon juice or drizzle with raw honey.

Green tea (but black or white tea may be substituted) is used in the following recipes to help you improve your L-theanine intake:

  • First, make a cup of matcha green tea that has been concentrated.
  • Simmer herbs like rosemary, ginger, wild sage, oregano, marjoram, mint, or dandelion in tea for an added antioxidant and taste boost.
  • These 34 green smoothie recipes call for iced green tea or matcha.
  • Desserts and baked products may be created using matcha green tea powder, such as handmade fruit muffins or pancakes.
  • Using iced green tea and this ice cream recipe, make homemade green tea coconut ice cream.

Last Thoughts

  • L-theanine (or simply theanine) is a non-essential amino acid found in green, black, and white teas, as well as supplements.
  • L-theanine is a calming amino acid that does not make you sleepy. It may help you relax, enhance your attention span and concentration, and have a good night’s sleep. L-theanine is not only soothing and centering, but it may also protect the heart and brain, as well as aid manage blood pressure and lessen schizophrenia symptoms.
  • Drinking many cups of good green tea and other teas every day is the greatest natural approach to get L-theanine.
  • When used as a supplement, L-theanine is harmless; however, it may diminish the effects of blood pressure drugs and stimulants. The normal daily dose ranges from 100 to 400 mg. Some individuals combine modest dosages of L-theanine and caffeine to boost concentration without feeling jittery.

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The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.


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