L-theanine is an amino acid derivative naturally found in all types of tea. Furthermore, it is present in many other plant extracts, but green tea seems the most common to include theanine into the diet.
L-theanine is known to produce anti-stress effects, and that is why drinking green tea is considered more beneficial, despite the caffeine content compared to black tea.
Research shows that taking L-theanine may present the benefits of balancing the stimulating effects of caffeine. As a result, it is the often-recommended remedy for calming anxiety and promoting relaxation.
Read on to learn more about the potential benefits of L-theanine for anxiety.
- Does L-Theanine Help With Anxiety?
- Can L-Theanine Cause Anxiety Or Make It Worse?
- L-Theanine Dosage For Anxiety: How Much To Take?
- L-Theanine And Anxiety Medication: What You Should Know
Does L-Theanine Help With Anxiety?
L-theanine has had many studies with human subjects dedicated to its mental health benefits and stress-reducing ability.
L-theanine affects anxiety by changing electrical activity in the brain. It supports the production of alpha brain waves that occur when relaxed but still awake.
An increasing amount of clinical evidence shows that even the smallest amount of L-theanine can increase alpha waves in the brain and increase relaxation while improving overall mood.
One study found that when 15 mg powdered theanine was used in tea preparation, it could significantly boost high levels of brain alpha waves, indicating that it may relax the mind without inducing drowsiness (1).
Also, it seems to balance the release of some neurotransmitters and chemicals in the brain, including dopamine, serotonin, and the inhibitory neurotransmitter glycine.
However, it does not skyrocket levels of excitatory neurotransmitters like dopamine. Instead, it increases levels of GABA by binding it to glutamate receptors and can inhibit this excitatory neurotransmitter.
On another level, L-theanine seems to increase brain-derived neurotrophic factor (BDNF). This is a naturally occurring protein responsible for maintaining, growing, and survival of neurons in the central nervous system.
Various studies have looked at the mechanism of theanine in promoting antipsychotic-like and antidepressant-like benefits. One study concluded that these effects of l-theanine occurred given the induction of BDNF in the brain (2).
The effects of L-theanine seem to be so potent because this non-essential amino acid can cross the blood-brain barrier, where it can perform its functions much more effectively.
Additionally, l-theanine benefits include using it as a treatment for ADHD regulation and mood enhancement. Also, it helps to increase focus, sharpen cognition, and improve memory and attention.
As a relaxing agent, theanine’s possible benefits and calming effect may even be helpful for mental health conditions such as bipolar disorder.
In addition, other areas of mental health show the potential for the promising effect of l-theanine, including using it as a treatment for OCD, generalized anxiety, panic disorder, and schizophrenia.
Does L-Theanine Calm You Down?
Research shows that theanine consumption in healthy individuals can reduce anxiety and attenuate blood pressure increases in physical or psychologically stressful situations (3).
One study recruited healthy university students assessing their anxiety levels using a standardized rating scale. Participants with high anxiety were put in one group and others with minimal anxiety in the second.
Both groups received water or water that included a 200 mg L-theanine supplement. Results showed that high anxiety students showed more significant improvement in their anxiety symptoms after receiving L-theanine.
Their anxiety symptoms improved in the areas of attentional performance, improved reaction times, and a slowing of their heart rate compared to members of the same group receiving placebo (4).
L-theanine benefits on the mind and body are considered so potent that its supplement form has also been used to improve sleep parameters.
Many people use it to calm down before bed, and it is suggested to take the supplement around half an hour to an hour before bedtime.
This amino acid can regulate serotonin levels and dopamine levels in the brain, which influence mood, sleep, and emotion, along with cortisol levels that help the body deal with stress.
Study findings show that combining GABA and L-theanine assisted participants to fall asleep faster and stay asleep longer.
In addition, by inhibiting neural activity, GABA can decrease mental and physical stress and facilitate sleep. This makes the two supplements a valid combination before bedtime.
Because serotonin converts to melatonin in the brain, improving serotonin levels ultimately results in enhanced melatonin levels which support a good night’s rest.
One study with 30 healthy adults gave participants either 200 mg L-theanine or a placebo for four weeks. Participants using theanine took less time to fall asleep, had fewer disruptions while sleeping, and took fewer medications than the placebo group (5).
Can L-Theanine Cause Anxiety Or Make It Worse?
While L-theanine is probably best known for its relaxation effects, it may also benefit those with major depression.
One study recruited 20 adults with major depressive disorder, administering L-theanine for eight weeks at 250 mg per day alongside their existing meds.
Study findings showed significant improvements in depressive symptoms, sleep disturbances, anxiety, and cognitive function (6).
Another study looked at its effect on patients with schizophrenia and schizoaffective disorder.
The study administered L-theanine at 400 mg a day for eight weeks and the patients’ existing antipsychotic treatments. Here, findings showed a reduction in anxiety symptoms and general psychopathology (7).
Green tea does not present any severe side effects for healthy individuals when taken in moderate amounts.
However, anyone suffering from specific conditions should be cautious when adding green tea into their diet.
If you take green tea as your primary source of L-theanine, then the caffeine content in green tea seems to present the bulk of the side effects associated with its consumption.
Caffeine, being a stimulant, can trigger mild to severe side effects such as headaches, dizziness, nervousness, disrupted sleep, irritability, nausea, and rapid heartbeat in some people.
But if you decide to take L-theanine supplements instead of green tea, you minimize the potential for these caffeine-related side effects.
However, when using supplements, it is essential to look at other ingredients included in the formula, especially if you are being treated for an anxiety disorder already.
L-Theanine Dosage For Anxiety: How Much To Take?
L-theanine supplements can carry between 100 and 400 mg of this amino acid. These doses are well tolerated and considered safe for consumption without causing any adverse side effects.
But for more severe anxiety, your doctor may specify your dose up to 600 to 800 mg per day divided into 200 mg doses every three to four hours to achieve similar effects.
Even though it is not habit-forming, experts recommend using L-theanine supplements for a short time, with studies going up to a daily dose of up to 900 mg for eight weeks.
Even though green tea can be consumed daily, whether L-theanine is possibly safe to use for more extended periods in supplement form is not established yet.
The last consideration is that L-theanine can interact with certain medications, including antihypertensive drugs.
Furthermore, it may lower blood pressure, so it’s best to consult with your healthcare practitioner if you take any prescription medications for high blood pressure, are expecting a baby, or are nursing.
L-Theanine And Anxiety Medication: What You Should Know
No published data indicate any drug interaction when combining L-theanine as a supplement and anxiety management drugs.
However, if you do use anything to manage your anxiety symptoms, it is strongly recommended to consult with your doctor first before starting any new supplementation.
On the other hand, using theanine as a supplement with stimulant drugs may reduce the efficacy of stimulant medications.
Taking L-theanine is a naturally effective treatment option for calming a stressed mind and relaxing a tense body.
When combined with GABA and other calming supplements, it is a beneficial amino acid that positively affects anxiety symptoms.
Its relaxing but not sedating effects on the brain make it a popular choice to help process anxiousness without drowsiness and assist sleep quality.
Therefore it is helpful for many mental health conditions, but more research is needed to establish its long-term safety.