Written by Christina Hanley 
BHSc (Nutritional Medicine), qualified nutritionist and ANTA member #20854, Health Content Lead at Mr Vitamins, with 8 years of clinical experience. 
 
Reviewed by Shuchna Vekariya 
BHSc (Naturopathy) | BBiomedSc (Hons) | ATMS Member #54792 | Naturopath at Mr Vitamins with over 1 year of clinical experience.  

 
Article last reviewed: 26/10/2026 

How we write and review health content · [Meet our practitioner team] 

Stress and concentration are more closely linked than most people realise. Managing everyday stress isn't only about feeling calmer, it's often what lets your mind work the way you need it to. A familiar feeling would be sitting down to start one task, and your mind is already three steps ahead, replaying a conversation, drafting a reply or remembering the thing you meant to do yesterday. 

How Stress Impacts Concentration 

Stress is a normal part of life, and in short bursts it can even be useful. It sharpens attention when you need it and helps you respond to pressure. The challenge comes when stress stops being occasional and starts being constant. 

When you feel wound up, your attention tends to narrow and jump. You might read the same paragraph three times, walk into a room and forget why, or find it harder to hold a train of thought while someone is talking. Sleep often suffers too, and tired minds find concentration harder still. 

Many people describe this as feeling scattered or foggy, feeling mentally busy, but not productive. It's a common experience during demanding periods at work, through study or while juggling family responsibilities. 

The Connection Between Stress and Cognition 

Cognition is the umbrella term for how your brain takes in, processes and uses information. It covers memory, attention, learning, decision-making and mental clarity, all the things you rely on to get through a busy day. 

Stress and cognition share a lot of the same territory. Your nervous system is involved in both, and when it's under sustained pressure, the mental resources you'd normally put towards focus and problem-solving get pulled elsewhere [1]. Broken sleep, skipped meals and long screen hour all contribute to the load building. This is why supporting a healthy stress response and supporting cognitive function often go hand in hand.  

Why L-Theanine Has Become a Popular Ingredient 

L-Theanine is an amino acid found naturally in the leaves of green tea (Camellia sinensis). It's often credited with the particular quality of tea: a sense of being settled and alert at the same time, rather than wired [2]. 

Research has centred on L-theanine's association with alpha brain wave activity, a pattern of brain activity linked with a relaxed state [3]. That combination of calm without drowsiness is a large part of why L-theanine has become such a widely discussed ingredient in stress and cognitive wellness conversations [4]. "L-theanine supports a calm, focused state of mind, helping support mental clarity during periods of high cognitive demand." Shuchna Vekariya BHSc (Naturopathy) | BBiomedSc (Hons) | ATMS Member #54792 | Naturopath at Mr Vitamins with over 1 year of clinical experience. 

You'd need a considerable amount of tea to reach the amounts used in research, which is why concentrated, standardised forms of L-theanine are commonly used in supplements [5,6]. 

Herbs of Gold L-Theanine 200mg 

Herbs of Gold L-Theanine 200mg (AUST L 451630) [7] provides high-strength theanine, an amino acid that assists mind relaxation, as part of a broader healthy lifestyle. It contains AlphaWave®, a purified form of theanine, at 200mg per capsule, the same form and dose used in published human trials [3]. 

Practitioner Q&A: When Do I Suggest L-Theanine? 

Q: Who tends to find L-theanine helpful? Adults who feel mentally wound up and find it's affecting their concentration, often during busy work periods, study or times of extra responsibility at home. 

Q: Will it make me drowsy during the day? L-theanine is generally associated with a calm but alert state rather than sedation, which is why many people take it during the day. Everyone responds differently, so it's worth discussing with a practitioner. 

Q: Does it replace stress management? No. Supplements sit alongside the basics: sleep, movement, nutrition and realistic workloads. They are designed to support a routine. 

Q: Is it suitable for everyone? Not always. It isn't recommended during pregnancy or breastfeeding, and caution applies if you take blood pressure medication or certain other prescriptions. Always check with a qualified healthcare professional first. 

Q: Should I check with a practitioner first? Yes. If you are pregnant or breastfeeding, taking blood pressure medication or other prescriptions, or managing an existing health condition, speak to our naturopaths at Mr Vitamins or your healthcare professional before starting. 

Why Qualified Advice Matters 

Focus isn't only about trying harder. When your mind is settled, concentration tends to follow more easily, which is why managing everyday stress is one of the most practical things you can do for your cognitive wellness. 

Sleep, movement, nutrition and boundaries lay the groundwork, and a product like Herbs of Gold L-Theanine 200mg can offer additional targeted support for a healthy stress response as part of that routine. Visit your local Mr Vitamins store or shop online and speak with one of our qualified team members to find the right solution for your individual health goals. 

Not sure if it's the right fit for you? Book a free 10-minute consultation with one of our practitioners online. 

 Always read the label and follow the directions for use. If symptoms persist, talk to your healthcare professional. This article is for educational purposes only and is not intended to replace professional medical advice. 

About This Article 

Full profiles: read more about Christina Hanley and Shuchna Vekariya, Naturopath | Mr Vitamins Parramatta on their author pages. 

Next scheduled review: August 2027, or earlier if the product listing, label indications or Australian clinical guidance change. 

This article is general information only and is not a substitute for individual medical advice. Always read the label and follow the directions for use. If symptoms persist, talk to your healthcare professional. 

How This Article Is Sourced 

General statements about stress, focus and cognition in this article are referenced to peer-reviewed human research, including systematic reviews and meta-analyses published within the last ten years. Information about Herbs of Gold L-Theanine 200mg (AUST L 451630) is taken from the product's label and its entry on the Australian Register of Therapeutic Goods. 

Where the product is discussed, permitted claims are limited to the indications accepted for its listing on the Australian Register of Therapeutic Goods and stated on its label. The research cited is included as general education and does not extend those indications, nor is it presented as evidence of any specific outcome. References 3 and 8 (Evans et al., 2021; Moulin et al., 2024) were conducted on the AlphaWave® form of theanine used in this product and are associated with the ingredient's supplier; the remaining references are independent. This disclosure is provided so readers can weigh the evidence for themselves. 

This article was written and reviewed by a qualified naturopath or nutritionist and is general education only. It is not personal health advice and does not take your individual circumstances into account. 

General Disclaimer 

This article is intended for general informational and educational purposes only. It does not constitute medical advice and is not a substitute for professional healthcare advice, diagnosis, or treatment. Always read the label and follow the directions for use, and if symptoms persist, talk to your healthcare professional. 

The information in this article is not intended to diagnose, treat, cure, or prevent any disease or health condition. References to health benefits reflect the current state of published research and the product's approved label indications, and are not claims made about any specific outcome. Individual results may vary. 

Vitamin, mineral and amino acid supplements should not replace a balanced diet. Herbs of Gold L-Theanine 200mg (AUST L 451630) is not recommended for use by pregnant or breastfeeding women. If you are taking prescription medications, including blood pressure medication, or have an existing health condition, consult a qualified healthcare professional before starting Herbs of Gold L-Theanine 200mg. Keep all supplements out of reach of children. 

© Mr Vitamins. All rights reserved. Content is reviewed periodically but may not reflect the most current research or regulatory guidance. 

References 

1. Shields, G.S., Sazma, M.A. & Yonelinas, A.P. (2016). The effects of acute stress on core executive functions: a meta-analysis and comparison with cortisol. Neuroscience & Biobehavioral Reviews, 68, 651–668. https://doi.org/10.1016/j.neubiorev.2016.06.038
2. Payne, E.R., Aceves-Martins, M., Dubost, J., Greyling, A. & de Roos, B. (2025). Effects of tea (Camellia sinensis) or its bioactive compounds L-theanine or L-theanine plus caffeine on cognition, sleep, and mood in healthy participants: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews, 83(10), 1873–1891. https://doi.org/10.1093/nutrit/nuaf054
3. Evans, M., McDonald, A.C., Xiong, L., Crowley, D.C. & Guthrie, N. (2021). A randomized, triple-blind, placebo-controlled, crossover study to investigate the efficacy of a single dose of AlphaWave® L-theanine on stress in a healthy adult population. Neurology and Therapy, 10(2), 1061–1078. https://doi.org/10.1007/s40120-021-00284-x
4. Hidese, S., Ogawa, S., Ota, M., Ishida, I., Yasukawa, Z., Ozeki, M. & Kunugi, H. (2019). Effects of L-theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial. Nutrients, 11(10), 2362. https://doi.org/10.3390/nu11102362
5. Gerolymos, C., Saddier, E., Boyer, L. & Fond, G. (2026). Cognitive and affective effects of L-theanine: a systematic review and meta-analysis of 31 randomized trials. Molecular Psychiatry. https://doi.org/10.1038/s41380-026-03727-9
6. Mátyus, R.O., Szikora, Z., Bodó, D., Vargáné Szabó, B., Csupor, É., Csupor, D. & Tóth, B. (2025). The effect of L-theanine on cognitive performance based on the systematic review and meta-analysis of randomized placebo-controlled clinical trials. Journal of Clinical Medicine, 14, 7710. https://doi.org/10.3390/jcm14217710
7. Therapeutic Goods Administration (2024). Australian Register of Therapeutic Goods public summary: L-Theanine 200mg, AUST L 451630. Sponsor: Herbs of Gold Pty Ltd. https://www.tga.gov.au/resources/artg/451630