L-Theanine for ADHD: Dosage and Benefits

L-Theanine for ADHD: Dosage and Benefits

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms such as inattention, hyperactivity, and impulsivity. While there are various treatment options available, including medication and therapy, many individuals seek alternative or supplementary approaches to manage their symptoms.

One such option gaining attention is L-Theanine, a compound found in tea leaves renowned for its calming effects. In this comprehensive guide, we delve into the potential benefits of L-Theanine for ADHD and explore appropriate dosage considerations.

What Is Attention Deficit Hyperactivity Disorder (ADHD)?

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodivergent condition that manifests in a variety of ways, including issues with attention, hyperactivity, and impulsivity. It's a condition that doesn't discriminate, affecting both children and adults, and can lead to complications in various aspects of life, such as school, work, and relationships.

The characteristics of ADHD are generally categorized into two types: inattentiveness and hyperactivity/impulsivity. Inattentiveness refers to difficulties with focus and attention, such as trouble staying on task or being easily distracted. Hyperactivity/impulsivity, on the other hand, involves behaviors like acting without thinking or being excessively active. According to the DSM-5, a person must exhibit at least six symptoms from one or both categories to be diagnosed with ADHD.

While ADHD is considered a disability, this is primarily because society expects individuals with ADHD to conform to neurotypical norms. People with ADHD have brains that work differently, and as such, they may require certain accommodations or tools to manage tasks and organize their time effectively. Despite the challenges, with the right support and treatment, individuals with ADHD can lead successful and fulfilling lives.

What Is L-Theanine?

L-Theanine, a non-protein, water-soluble amino acid, is a natural component predominantly found in green and black tea. This compound, also available in supplement form, has gained popularity for its calming properties. Unlike many other relaxants, L-Theanine induces tranquility without causing drowsiness, making it a helpful supplement.

The compound's ability to cross the blood-brain barrier further enhances its effectiveness. This unique characteristic allows it to directly influence brain functions, contributing to its wide range of health benefits.

L-Theanine and ADHD

L-Theanine has been studied for its potential effects on attention deficit hyperactivity disorder (ADHD). While research is still ongoing and conclusive evidence is lacking, there are several mechanisms through which L-Theanine may alleviate ADHD symptoms:

Promotion of Relaxation

L-Theanine is known for its calming effects on the mind and body. It increases alpha brain waves, which are associated with relaxation, while decreasing beta brain waves, which are associated with stress and agitation.

A study by Nobre et al (2008) found that L-Theanine significantly increases activity in the alpha frequency band which indicates that it can relax the mind without inducing drowsiness. This calming effect may help reduce hyperactivity and impulsivity, two core symptoms of ADHD.

Improved Focus and Attention

L-Theanine has been shown to enhance cognitive function by improving attention and focus through increasing levels of neurotransmitters such as dopamine and serotonin, which are involved in attention regulation and mood stabilization.

This is supported by a 2012 study that found that people who took 100 mg of L-Theanine made fewer errors in an attention task than those in the placebo group. Drinking 50 mg of caffeine or combining L-theanine and caffeine also improved people’s focus.

A more recent placebo-controlled clinical trial confirmed those results and found that L-Theanine contributes to improving attention, thus enhancing working memory and executive functions.

Although the above research didn't focus on those with ADHD, Kahathuduwa et al. (2019) discovered that L-Theanine, caffeine, and their combination improved sustained attention and overall cognitive performance in children with ADHD, possibly by decreasing mind wandering.

While L-Theanine alone and caffeine alone seemed to increase impulsivity, the combination appeared to decrease impulsivity in children with ADHD. As such, the combination of L-Theanine and caffeine may have the potential to be used as a therapeutic method to manage symptoms in children with ADHD.

Reduced Anxiety

ADHD is associated with heightened levels of anxiety, with up to 50% of individuals with ADHD having one or more comorbid anxiety disorders. L-Theanine's anxiolytic (anxiety-reducing) properties may help individuals with ADHD manage anxiety symptoms, allowing for better attentional control and impulse regulation.

L-Theanine does this by increasing levels of calming neurotransmitters like GABA and serotonin, and regulating the body's stress response, all of which contribute to a sense of calmness and emotional well-being without sedation. Its interactions with glutamate receptors also help dampen neuronal excitability, further alleviating symptoms of anxiety.

Improved Sleep

According to NHS statistics, 50-75% of adults with ADHD experience sleep problems, ranging from insomnia to secondary sleep conditions. Those with inattentive ADHD are more likely to go to bed at a later time, whereas those with hyperactive and/or impulsive symptoms are more likely to experience insomnia. Those with the combined sub-type tend to experience both a later bedtime and poor sleep quality.

One of the key benefits of L-Theanine is its potential to improve sleep quality. A study by Williams et al. (2016) found that doses of 250 mg and 400 mg of L-Theanine greatly improved sleep in animals and humans. They further discovered that 200 mg of L-Theanine reduced resting heart rate, indicating its ability to promote relaxation.

This was further consolidated by Kim et al. (2019) who found that a GABA/L-Theanine mixture could be used to treat insomnia and sleep disorders as a concept of nonpharmacological management of sleep.

L-Theanine Caffeine Combination

As mentioned previously, some studies have indicated that the combination of L-Theanine and caffeine may enhance cognitive performance and attention span, offering potential benefits for those with ADHD.

In a systematic review, Sohail et al. (2021) found that the combination of caffeine and L-Theanine improved short-term sustained attention and overall cognition. Reversed task-related mind-wandering and improved inhibitory control were also seen among boys with ADHD. Overall, the researchers concluded that the combination of L-Theanine and caffeine is likely a safe and effective cognitive enhancer.

However, it's important to note that more comprehensive research is needed to fully understand the potential benefits and optimal dosage of L-Theanine for ADHD.

L-Theanine Dosage

L-Theanine, a naturally occurring amino acid in black and green tea, is also available as an over-the-counter dietary supplement. These supplements come in different formats, including tablets, liquids, powders, and capsules. These supplements contain as little as 25 milligrams per serving, while others may contain up to 200 milligrams.

NMN Bio's NAD+ Brain supplement includes 100 mg of L-Theanine per serving. This supplement is designed to enhance brain health, offering potential advantages for cognitive function and attention regulation, particularly beneficial for individuals managing ADHD. Depending on your needs, you can take anywhere from one to seven capsules per day.

L-Theanine for Children

The amount of L-Theanine you should take is influenced by various elements such as your age, weight, and overall health condition. It's important to note that the dosage differs for children and adults.

For instance, in a study, children were given 2.5 mg per kilogram of body weight per day, while adults were given 200 mg per day. This dosage showed promising results, including improved concentration and reduced impulsivity. However, it's crucial to remember that this study was relatively small, and more extensive research is needed to confirm these findings.

One of the children in the study developed facial tics, which disappeared after discontinuing the L-Theanine treatment. This highlights the importance of monitoring for potential side effects when taking L-Theanine, even though it is generally considered safe with few reported adverse effects.

Given the lack of standardized dosage and the potential for side effects, it's recommended that parents consult with a doctor before starting their child on L-Theanine supplements for ADHD. A healthcare professional can provide guidance on the appropriate dosage based on the child's weight and overall health, and monitor for any potential side effects.

Potential Side Effects of L-Theanine

While taking L-Theanine is generally well-tolerated, it's crucial to be aware of potential side effects. Although rare, some individuals may experience:

  • Headaches
  • Dizziness
  • Upset stomach
  • Drop in blood pressure
  • Nausea
  • Facial tics

L-Theanine and Medication Interactions

L-Theanine, while generally safe, can interact with certain medications, warranting caution. Antidepressants and blood pressure medications are two such examples. The interaction between these medications and L-Theanine can potentially lead to unforeseen complications. This is due to the higher dosage of L-Theanine present in supplement form compared to its natural occurrence in tea.

It's crucial to consult with your healthcare provider before incorporating L-Theanine into your regimen, especially if you're on prescribed medications. This is to ensure that the supplement doesn't interfere with the effectiveness of your current treatment plan or cause adverse reactions.

Conclusion: L-Theanine for ADHD Treatment

L-Theanine presents a promising approach for managing symptoms of Attention Deficit Hyperactivity Disorder (ADHD). Its calming effects, ability to enhance focus and attention, and potential to reduce anxiety offer valuable benefits to individuals with ADHD.

While research into its efficacy is ongoing, the evidence suggests that L-Theanine, particularly when combined with caffeine, may offer a safe and effective means of improving cognitive performance and attention span.

However, optimal dosage and potential side effects warrant careful consideration, highlighting the importance of consulting healthcare professionals before integrating L-Theanine into ADHD treatment plans.

Further research is needed to fully elucidate its therapeutic potential and establish standardized guidelines for its use in ADHD management.

NMN Bio's NAD+ Brain is formulated with 100 mg of L-Theanine per serving. The supplement supports brain health and offers additional benefits for cognitive function and attention regulation that individuals with ADHD may benefit from.

Researched and reviewed by Dr Elena Seranova, Ph.D.

Dr Seranova holds a master's degree in Translational Neuroscience from the University of Sheffield, UK, and a Ph.D in Stem Cell Biology and Autophagy from the University of Birmingham, UK. She is a published author in multiple peer-reviewed journals, including Cell Reports and Developmental Cell.


Baba et al. Effects of L-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study. Journal of Medicinal Food. (2021)

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Higashiyama et al. Effects of L-Theanine on attention and reaction time response. Journal of Functional Foods. (2011)

Kahathuduwa et al. L-Theanine and Caffeine Improve Sustained Attention, Impulsivity and Cognition in Children with Attention Deficit Hyperactivity Disorders by Decreasing Mind Wandering. Current Developments in Nutrition. (2019)

Kim et al. GABA and L-Theanine mixture decreases sleep latency and improves NREM sleep. Pharmaceutical Biology. (2019)

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