Ashwagandha and L-Theanine: A Comprehensive Guide

Ashwagandha and L-Theanine: A Comprehensive Guide

Ashwagandha and L-Theanine are well-known in the natural health and wellness industry for their profound effects on mental and physical health. Originating from distinct cultural and botanical backgrounds, these supplements are often sought after for their stress-reducing properties.

In this article, we'll explore L-Theanine and ashwagandha, exploring their benefits, side effects, and how they can be integrated into daily wellness routines.

What is L-Theanine?

L-Theanine is a calming amino acid most commonly found in tea leaves, particularly green tea. Unlike many supplements that have a single pointed effect, L-Theanine is celebrated for its ability to promote relaxation without drowsiness, making it highly sought after for its calming effects on the mind.

The compound works by increasing the levels of certain neurotransmitters, such as dopamine and gamma-aminobutyric acid (GABA), in the brain, which promotes relaxation and reduces stress and anxiety. It also has the unique ability to cross the blood-brain barrier, allowing it to directly influence brain function and induce its calming effects.

What is Ashwagandha?

Ashwagandha, a plant native to Asia and Africa, has been a cornerstone of traditional Indian medicine, Ayurveda, for centuries. This plant is classified as an adaptogen, a unique category of ingredients that assist the body in achieving a state of balance or homeostasis. Ashwagandha's adaptogenic properties make it a versatile remedy for a variety of conditions, including anxiety, stress, poor immunity, and inflammation.

The source of Ashwagandha's therapeutic effects lies in its biochemical mechanisms. It exhibits GABA-mimetic properties, meaning it imitates the action of GABA, a neurotransmitter that promotes relaxation. It also has cholinergic effects, which help maintain normal acetylcholinesterase levels, thereby activating the parasympathetic system.

What Are The Benefits Of L-Theanine And Ashwagandha?

These ancient substances, backed by modern science, offer a plethora of health benefits.

1. Reduced Anxiety and Depression

L-Theanine works by regulating levels of GABA, a neurotransmitter responsible for relaxation pathways in the body. By increasing GABA, L-Theanine can slow down the overactivation of nerves during anxiety states, promoting a calming effect. This is confirmed by many studies, including research by Hidese et al. (2017), who found that L-Theanine administration (250 mg/day) to twenty individuals with major depressive disorders reduced their Hamilton Depression Rating Scale score after eight weeks.

On the other hand, ashwagandha works on a hormonal level to reduce anxiety by modulating the body's stress response system. By lowering the stress hormone cortisol, ashwagandha helps regulate the body's physiological reactions to stress, leading to a calmer and more balanced state of mind. A 2021 systematic review of 41 studies found that ashwagandha significantly reduced stress and anxiety levels, reduced sleeplessness and fatigue, and reduced serum cortisol levels compared with placebo.

Thus, both L-Theanine and ashwagandha offer significant benefits in reducing anxiety, albeit through different mechanisms.

2. Better Sleep

The benefits of L-Theanine and ashwagandha extend to improving sleep quality. L-Theanine, in particular, has been shown to enhance both the duration and quality of sleep by increasing the production of GABA and serotonin, neurotransmitters that play a significant role in promoting sleep.

Oral treatment of L-Theanine (200 mg) has also been found to improve the quality of sleep by increasing alpha brain waves, increasing parasympathetic nerve system responses, and decreasing sympathetic nerve system responses. A similar improvement in sleep was observed in healthy participants' sleep disturbance, as well as in participants diagnosed with major depressive disorder.

Ashwagandha has also demonstrated potential in enhancing sleep scores compared to a placebo. This is likely due to its role in reducing cortisol levels, the stress hormone that can interfere with sleep. By lowering cortisol levels and reducing stress and anxiety, ashwagandha can help you sleep better, thereby reducing stress and anxiety.

In a double-blind, placebo-controlled study, Langade et al. (2021) found that ashwagandha root extract can improve sleep quality and help manage insomnia. Similarly, a 2020 study observed a 72% improvement in sleep quality in 150 healthy individuals who reported having poor sleep quality after six weeks of taking ashwagandha extract compared with 29% in the placebo group.

3. Reduced Inflammation

Ashwagandha and L-Theanine also play a significant role in reducing inflammation, a silent but harmful condition that can lead to chronic diseases. Ashwagandha, in particular, has been found to lower levels of chronic inflammation in the body. Preclinical studies have demonstrated the ability of ashwagandha to regulate mitochondrial function and apoptosis and reduce inflammation by inhibiting inflammatory markers such as cytokines, nitric oxide, and reactive oxygen species.

Evidence presented by Kanjilal et al. (2021) revealed that ashwagandha extract applied for a period of 8 to 12 weeks can be useful in managing arthritis symptoms in patients. Administration of ashwagandha was also found to increase white blood cells and bone marrow cells and the circulation of antibodies and antibody-producing cells. This suggests that ashwagandha not only helps in reducing joint inflammation and pain associated with arthritis but also enhances the body's immune response, potentially improving overall health resilience.

Numerous cell and animal studies have also shown that L-Theanine plays an immunoregulatory role in inflammation, nerve damage, the intestinal tract, and tumors by regulating lymphocyte function, glutathione synthesis, and the secretion of cytokines and neurotransmitters.

Thus, the benefits of ashwagandha and L-Theanine extend beyond mental health, offering a holistic approach to wellness by also addressing physical health issues like inflammation.

4. Improved Cognitive Function

The cognitive benefits of L-Theanine and ashwagandha are quite impressive. L-Theanine has been shown to enhance cognitive performance, particularly in areas of focus and memory. It achieves this by increasing the levels of serotonin, dopamine, and GABA in the brain, neurotransmitters that play a crucial role in mood regulation, alertness, and cognitive function. Additionally, L-Theanine has been found to manage cortisol levels, a hormone that when elevated, can impair cognitive function.

On the other hand, ashwagandha works more on a hormonal level, particularly with cortisol, a stress hormone that can negatively impact cognitive function when in excess. Research suggests that by managing cortisol levels, ashwagandha can help improve cognitive performance, particularly in stressful situations.

By working on different aspects of brain health - neurotransmitters and hormones - the two compounds can provide a comprehensive approach to cognitive enhancement. This makes them a powerful tool for those looking to improve their cognitive function, whether to combat age-related cognitive decline or simply to perform at their best in their daily lives.

Potential Side Effects of L-Theanine

Despite the well-known benefits of L-Theanine, it's important to note some of the potential side effects:

  • Headaches
  • Dizziness
  • Nausea
  • Upset stomach
  • Sleep disturbances (if taken in excessive amounts)
  • Low blood pressure (hypotension) in some individuals
  • Interaction with certain medications (such as blood pressure medications or stimulants)

Potential Side Effects of Ashwagandha

  • Gastrointestinal upset (nausea, diarrhea, stomach pain)
  • Drowsiness or sedation (especially at higher doses)
  • Changes in blood sugar levels (may affect individuals with diabetes)
  • Thyroid hormone disruption (may affect individuals with thyroid disorders)
  • Interaction with medications (such as sedatives, thyroid medications, or medications for diabetes)
  • May increase the effects of certain drugs that suppress the immune system

The Synergistic Effects of L-Theanine and Ashwagandha

The combination of L-Theanine and ashwagandha creates a potent formulation for stress and anxiety relief. On a mechanistic level, the GABA activators of both ingredients work in synergy. L-Theanine increases GABA levels, while ashwagandha mimics its action, creating a multiplier effect. Both also have hormonal-type effects, creating endocrine system synergisms, which are crucial for cortisol control.

L-Theanine's ability to increase alpha brain waves (associated with relaxation) and reduce beta and theta waves (associated with excitement and light sleep) could potentially enhance the molecular mechanisms affected by ashwagandha.

In addition to this, L-Theanine works quickly, usually within 30-60 minutes whereas ashwagandha, an adaptogen, takes a bit longer to kick in, but its effects are long-lasting. The beauty of this combination lies in the fact that while l-theanine provides more immediate relief, ashwagandha continues to work in the background, providing sustained benefits.

However, it's important to note that although the combination of L-Theanine and ashwagandha offers a promising natural solution for managing stress, anxiety, and cognitive function, scientific research is needed to understand their combined potential.

How To Consume L-Theanine and Ashwagandha

L-Theanine and ashwagandha are commonly consumed as dietary supplements. L-Theanine is often found in green tea or available in supplement form, typically taken orally with water. Ashwagandha is available as a powder, capsule, or liquid extract and can be consumed with water, juice, or added to smoothies.

The recommended dosage for L-Theanine and ashwagandha can vary depending on factors such as age, weight, health status, and the specific product formulation. However, typical dosages are as follows:

  • L-Theanine: Daily doses of 100 mg are commonly used to promote relaxation and reduce stress.
  • Ashwagandha: Standardized extracts typically recommend daily doses ranging from 300-600 mg for general stress relief and immune support.

It's important to start with the lowest effective dose and gradually increase as needed while monitoring for any potential side effects. It's also advisable to consult with a healthcare professional, especially if you have underlying health conditions or are taking medications, to determine the most appropriate dosage for your individual needs.

NMN Bio presents its NAD+ Brain, providing a holistic approach to cognitive vitality and general wellness. Crafted meticulously, this blend contains 100 mg of L-Theanine per serving and other enriching components, contributing to numerous facets of brain functionality. From fostering serenity and mental acuity to sharpening focus and memory, this blend offers comprehensive support for your brain health.

Key Takeaways

Incorporating L-Theanine and ashwagandha into your daily routine can offer a great combination for managing everyday stress and promoting overall well-being. These natural supplements, with their unique mechanisms of action, provide a holistic approach to health.

By reducing anxiety, improving sleep quality, combating inflammation, and enhancing cognitive function, including energy and focus, L-Theanine and ashwagandha offer a comprehensive solution for navigating life's challenges. However, it's essential to use them responsibly, following recommended dosages and consulting with a doctor to ensure safety and effectiveness in achieving your health goals.

As you embark on your journey towards holistic wellness, exploring solutions that nurture both your mind and body is essential. NMN Bio's NAD+ Brain offers a comprehensive approach to cognitive health and overall well-being. With its carefully crafted formula, which includes 100 mg of L-Theanine per serving, alongside other beneficial ingredients, this blend supports various aspects of brain function, from promoting calmness and mental clarity to enhancing focus and memory.

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)

Chen et al. L-Theanine and Immunity: A Review. Molecules. (2023)

Davis & Kuttan. Immunomodulatory activity of Withania somnifera. Journal of Ethnopharmacology. (2000)

Deshpande et al. A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults. Sleep Medicine. (2020) 

Hidese et al. Effects of chronic L-Theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatrica. (2017)

Hidese et al. Effects of L-Theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial. Nutrients. (2019)

Kanjilal et al. Analysis of Clinical Trial Registry of India for Evidence of Anti-Arthritic Properties of Withania somnifera (Ashwagandha). Alternative Therapies in Health and Medicine. (2021)

Langade et al. Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study. Journal of Ethnopharmacology. (2021)

Lopresti & Smith. Ashwagandha (Withania somnifera) for the treatment and enhancement of mental and physical conditions: A systematic review of human trials. Journal of Herbal Medicine. (2021)

Mikulska et al. Ashwagandha (Withania somnifera)-Current Research on the Health-Promoting Activities: A Narrative Review. Pharmaceutics. (2023)

Rao et al. In search of a safe natural sleep aid. Journal of the American College of Nutrition. (2015)

Remenapp et al. Efficacy of Withania somnifera supplementation on adult’s cognition and mood. Journal of Ayurveda and Integrative Medicine. (2022)