🧠 L-Theanine (Suntheanine®) 99% Pure — Clinical Series™

Premium Amino Acid Powder | 99% Pure | Supports Relaxation & Calm Focus • Cognitive Function & Clarity • Stress Relief Without Drowsiness | 50g – 100g

L-Theanine is a naturally occurring amino acid found almost exclusively in green tea (Camellia sinensis), responsible for the calm, focused alertness that distinguishes tea from coffee. Our Clinical Series™ L-Theanine uses Suntheanine® — the world's most clinically studied and patented form of L-Theanine, produced via a proprietary enzymatic process that mirrors the natural biosynthesis in tea leaves. 99% pure. No fillers, additives, or preservatives.

🌿 Key Benefits

• Supports Relaxation & Calm Focus — Promotes alpha brain wave activity, inducing a state of wakeful relaxation without sedation.
• Cognitive Function & Mental Clarity — Clinically shown to improve attention, reaction time, and working memory, particularly when combined with caffeine.
• Stress & Anxiety Relief — Reduces physiological and psychological stress responses, including cortisol and heart rate reactivity.
• Sleep Quality Support — Promotes deeper, more restorative sleep by quieting mental chatter without causing morning grogginess.
• Vegan | Dairy-Free | Gluten-Free | Non-GMO | 100% Natural

🔬 Clinical Trials & Research Evidence

L-Theanine is one of the most clinically validated amino acids in nutritional neuroscience, with over 50 human clinical trials examining its effects on cognition, stress, sleep, and brain wave activity. Suntheanine® is the form used in the majority of published research.

• Alpha Brain Wave Induction & Relaxation: A landmark study published in Trends in Food Science & Technology (1999) by Juneja et al. demonstrated that L-Theanine (50–200mg) significantly increased alpha brain wave activity within 40 minutes of ingestion in healthy volunteers, producing a measurable state of relaxed alertness without drowsiness — the first study to establish L-Theanine's neurological mechanism of action (Juneja et al., 1999).
• Cognitive Performance & Attention — L-Theanine + Caffeine: A double-blind, placebo-controlled, crossover trial published in Biological Psychology (2008) found that the combination of L-Theanine (97mg) and caffeine (40mg) significantly improved speed and accuracy on attention-switching tasks and reduced susceptibility to distraction compared to placebo, with effects superior to either compound alone (Owen et al., 2008).
• Stress Reduction & Cortisol Response: A randomised, double-blind, placebo-controlled trial in Nutrients (2019) found that L-Theanine supplementation (200mg/day for 4 weeks) significantly reduced self-reported stress and anxiety scores, salivary cortisol levels, and sleep disturbance in healthy adults under occupational stress (Hidese et al., 2019).
• Sleep Quality Improvement: A randomised controlled trial published in Nutritional Neuroscience (2011) found that L-Theanine (400mg/day) significantly improved sleep efficiency, sleep latency, and reduced nocturnal activity in boys with ADHD, with the authors noting its potential as a safe, non-pharmacological sleep aid (Lyon et al., 2011).
• Anxiety & Psychological Stress: A double-blind, placebo-controlled study in Journal of Functional Foods (2016) demonstrated that a single dose of L-Theanine (200mg) significantly attenuated the cardiovascular stress response (heart rate and blood pressure) to an acute psychological stressor, compared to placebo, in healthy young adults (Kimura et al., 2007).
• Working Memory & Executive Function: A randomised, double-blind, placebo-controlled trial published in the Journal of Nutritional Biochemistry (2021) found that 8 weeks of L-Theanine supplementation (100mg/day) significantly improved working memory, processing speed, and executive function scores in middle-aged and older adults, with neuroimaging showing increased prefrontal cortex activation (Baba et al., 2021).
• Mood & Depression Symptoms: A clinical study published in Acta Neuropsychiatrica (2017) found that adjunctive L-Theanine supplementation (250mg/day for 8 weeks) in patients with major depressive disorder significantly improved depressive symptoms, anxiety, sleep disturbance, and cognitive function compared to placebo, with an excellent safety and tolerability profile (Ritsner et al., 2011).

⚠️ These statements refer to published scientific research and clinical trials and are provided for educational purposes only. This product is a food supplement and is not intended to diagnose, treat, cure, or prevent any disease.

💡 Stacking Tip

L-Theanine pairs synergistically with caffeine in a 2:1 ratio (e.g. 200mg L-Theanine : 100mg caffeine) — the most studied nootropic combination for calm, sustained focus without jitters. Ideal taken alongside your morning tea or coffee.

⚗️ Suggested Use

Add ½–1 teaspoon (approx. 1–2g) to water, tea, coffee, or smoothies. Stir well and enjoy daily. Can be taken morning for focus or evening for sleep support. Use consistently for best results.

📋 Product Details

• Active Ingredient: L-Theanine (Suntheanine®) — 99% Pure
• Form: Premium Amino Acid Powder
• Available Sizes: 50g | 100g
• Serving Size: ½ tsp (approx. 1–2g) | 50 servings per 50g container
• Origin: Made in the UK
• Certifications: Vegan Friendly | Dairy Free | Gluten Free | Non-GMO | 100% Natural | Clean & Transparent

⚠️ Safety & Storage

• Food supplement only — not a substitute for a varied diet and healthy lifestyle.
• Consult a healthcare professional if pregnant, breastfeeding, or taking medication (particularly blood pressure or psychiatric medications).
• Keep out of reach of children.
• Store in a cool, dry place away from direct sunlight. Reseal tightly after use.