Amino acid found in tea that promotes relaxation without drowsiness.
How it works
L-Theanine increases alpha brain wave activity and boosts GABA, serotonin, and dopamine levels, promoting calm focus.
Evidence-based uses
Works well combined with magnesium. Promotes relaxation without sedation.
Clinical Evidence
Systematic review of 9 studies found 200-400mg L-theanine improved sleep quality, reduced sleep latency, and enhanced next-day alertness without sedation in adults with stress-related sleep issues.
L-theanine (200mg daily) significantly decreased sleep latency, reduced sleep disturbance scores, and increased sleep quality compared to placebo in adults with generalised anxiety.
Can be taken as needed for acute stress. Works within 30-60 minutes.
Clinical Evidence
RCT found 200mg L-theanine significantly reduced salivary cortisol and subjective stress responses to an acute stressor compared to placebo, with effects within 1 hour of ingestion.
Promotes calm focus. Works well with caffeine. Fast-acting.
Clinical Evidence
Crossover RCT found 200mg L-theanine improved attention and reaction time during demanding cognitive tasks, with effects observed within 1-2 hours of ingestion.
Safety
L-Theanine may have mild blood pressure lowering effects, potentially enhancing antihypertensive medications. Generally considered safe but monitor.
Compare prices
3 products compared across Australian retailers. Sorted by price per serve.
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| Product | Price | /serve | |
|---|---|---|---|
Best NOW Foods L-Theanine 200 mg, 120 Veg Capsules iHerb | $17.99 | $0.15 | |
Thorne Thorne Theanine 200mg 90 Caps iHerb | $42.00 | $0.47 | |
Thorne PharmaGABA-250, 60 Capsules Thorne | $54.99 | $0.92 |
Prices in AUD. Some links are affiliate links — we may earn a commission at no extra cost to you.
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Also consider
Mineral
Essential mineral involved in 300+ enzymatic reactions including sleep regulation and stress response.
Hormone
Natural sleep hormone that regulates circadian rhythm.
Herb
Traditional herbal remedy used for centuries to promote sleep.
Herb
Adaptogenic herb that may help the body manage stress and boost energy.
Head to head
L-Theanine has 1 known interaction. Check if it's safe with your medications.
Evidence Lab
Magnesium glycinate, L-theanine, ashwagandha, glycine and apigenin — ranked by clinical evidence. Melatonin is prescription-only in AU, so these are the best OTC options.
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This information is for educational purposes only and is not intended as medical advice. Always consult a healthcare professional before starting any supplement. Evidence ratings are based on peer-reviewed clinical research. Individual results may vary.