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Double Strength L-Theanine 200 mg

NOW
4.7
★ ★ ★ ★ ★
(43456 ratings)
Theanine 200 mg
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Score85
A substantial 200 mg L-theanine amount offers efficient calm-focus support, while the small inositol addition contributes little. Broader cognitive, mood, and sleep pathways remain uncovered.
How scoring works
Quantity:60 Capsule(s) • (60 servings)
Goals:
Stress Relief
Brain Health
Cognitive Support
Mood Support
Sleep Support
Productivity Boost
Mental Focus

Score 85

A substantial 200 mg L-theanine amount offers efficient calm-focus support, while the small inositol addition contributes little. Broader cognitive, mood, and sleep pathways remain uncovered.
How scoring works

Also available as

1 option
120 servings Theanine 200 mg • 120 Capsule(s) • 120 servings $20.78 ($0.17 per serving)
$14.54($0.24 per serving)
Vitacost
$ 17.03
iHerb
$ 15.91
Daily Vita
$ 15.10
Pure Formulas
$ 14.54
Amazon
$ 15.79
iHerb
$ 15.91
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Analysis

A 200 mg L-theanine capsule provides a substantial amount for calm attention and situational stress. The added 100 mg of inositol is clearly disclosed but contributes only modest support at that amount.

The formula fits people whose focus, mood, or sleep is disrupted by mental tension. It is not a broad cognitive or sleep formula and does not directly increase alertness or regulate circadian timing.

One capsule per serving and efficient active delivery make regular use straightforward. Theanine sourcing lacks a branded purity signal, while inactive ingredients were not supplied.

Who is it for
  • Adults seeking calm focus without a stimulant
  • People whose stress interferes with concentration
  • Users who want one capsule per serving
Best for
  • Situational stress relief
  • Calm daytime focus
  • Pre-sleep mental relaxation

Pros

  • Substantial 200 mg L-theanine amount
  • One-capsule serving
  • Clearly disclosed active amounts
  • Efficient active-ingredient value

Cons

  • Inositol amount is modest
  • Generic theanine source
  • Narrow cognitive and sleep coverage

Nutrient quality

94 Highest impact

L-theanine is a defined amino acid, although no branded source or purity marker is supplied. The L-theanine amount is well aligned with common calming and focus use.

.

Ingredient transparency

81 Highest impact

Every supplied active ingredient has a specific amount. No proprietary blend hides a meaningful active dose.

.

Customer satisfaction

68 High impact

The supplied aggregate rating is strong, although no specific comments are included. The large rating count makes the aggregate result relatively stable.

.

Value for money

93 Highest impact

Formula quality provides strong support for the product positioning. Dose-adjusted serving value appears strong, while the formula avoids obvious low-value padding.

.
Report analysis

Goals

Stress Relief
Stress Relief
Impact
Highest effect
A Goal FitA Strength of SupportB- CoverageA Formula Quality
Theanine · 200 mg

L-theanine provides direct, non-sedating calming support, while inositol adds a secondary mood-related pathway. The formula is well aligned with daytime stress and avoids sedatives or stimulants.

The L-theanine amount sits comfortably within the effective range and is clearly disclosed. Generic sourcing lacks a stated purity standard, while the inositol amount is modest relative to standalone use.

Study evidence
Theanine Supportive 16 studies
Brain Health
Brain Health
Impact
Highest effect
B Goal FitA Strength of SupportC+ CoverageA Formula Quality

L-theanine may support focused calm and attention without acting as a stimulant. The clearly disclosed amount provides meaningful support for this narrow cognitive pathway.

Inositol adds little at the listed amount, while the generic theanine source lacks added purity assurance. The formula is best suited to people whose focus is disrupted by tension rather than those seeking broad memory support.

Study evidence
Theanine Supportive 17 studies
Cognitive Support
Cognitive Support
Impact
Highest effect
B Goal FitA Strength of SupportC- CoverageA Formula Quality
Theanine · 200 mg

L-theanine is supplied at a strong amount for calm attention and stress-related mental performance. Inositol adds a modest neuronal-signaling contribution but is not a well-established cognitive active at this level.

The transparent two-ingredient formula gives useful depth to one primary pathway without excessive label complexity. Memory, cerebral circulation, and neuro-regenerative support are not meaningfully covered.

Study evidence
Theanine Supportive 25 studies
Mood Support
Mood Support
Impact
Highest effect
B Goal FitA- Strength of SupportC+ CoverageA+ Formula Quality

L-theanine provides direct calming support, while inositol adds a secondary mood-related pathway. The formula is focused on reducing tension rather than covering stress hormones or neuroprotection.

The theanine amount is strong and fully disclosed, though its source lacks added purity details. Both ingredients form a clean, coherent combination without unnecessary padding.

Study evidence
Theanine Supportive 12 studies
Sleep Support
Sleep Support
Impact
Highest effect
B- Goal FitA Strength of SupportC+ CoverageA Formula Quality
Theanine · 200 mg

L-theanine reaches a well-supported amount for promoting a calm mental state before bed. Inositol may add gentle support, although its role in sleep is less established at the listed amount.

Both actives are separately disclosed in one capsule. The focused blend avoids sedatives and is best suited to sleep difficulty linked to mental tension rather than circadian disruption.

Study evidence
Theanine Supportive 8 studies
Productivity Boost
Productivity Boost
Impact
High effect
B+ Goal FitA- Strength of SupportD+ CoverageB+ Formula Quality
Theanine · 200 mg

L-Theanine at a full serving may support calm concentration, particularly when paired with caffeine elsewhere in the routine. Credible human evidence supports relaxed attention, though theanine alone is not a strong alertness enhancer.

The 200 mg amount sits squarely in the commonly effective range. Theanine and a small inositol amount form a compatible calming combination without opposing mechanisms.

Study evidence
Theanine Supportive 5 studies
Mental Focus
Mental Focus
Impact
High effect
B- Goal FitA- Strength of SupportD CoverageB+ Formula Quality
Theanine · 200 mg

L-theanine may promote calm attention without relying on a stimulant. The benefit is generally more pronounced when paired with caffeine, which is not included.

The 200 mg dose is clearly stated and sits in a well-established supplemental range. Inositol adds little direct support for mental focus at the listed amount.

Study evidence
Theanine Supportive 19 studies

Ingredients

IngredientAmount per serving
L-Theanine
200 mg
Inositol
100 mg
Gluten Free Adults 18–50 Vegan Kosher Dairy Free Vegetarian
Report overview
Theanine · 200 mg OverallScore92
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

The 200 mg L-Theanine serving is clearly disclosed and sits comfortably in the optimal range. Its generic source lacks branded or purity-specific quality evidence. Strong active-dose efficiency supports excellent value.

View ingredientView products
Loading alternative details
87 Performance

L-Theanine 200 mg Double Strength

Swanson
<p>200 mg of clearly identified branded L-theanine gives the formula a clear and relevant foundation. The branded source provides clearer ingredient identity than the original generic theanine listing.</p>
85 Performance

L-Theanine 150 mg

Solgar
<p>150 mg of clearly identified branded L-theanine gives the formula a clear and relevant foundation. The branded source provides clearer ingredient identity than the original generic theanine listing.</p>
87 Performance

L-Theanine 100 mg

California Gold Nutrition
<p>100 mg of clearly identified branded L-theanine gives the formula a clear and relevant foundation. The branded source provides clearer ingredient identity than the original generic theanine listing.</p>
85 Budget

Double Strength L-Theanine 200 mg

NOW
<p>A lower serving cost comes with 200 mg of clearly stated l-theanine. The ingredient profile remains focused on theanine and offers a practical alternative to the original formula.</p>
84 Budget

L-Theanine 200 mg

Advance Physician Formulas
<p>A lower serving cost comes with 200 mg of clearly stated l-theanine. The ingredient profile remains focused on theanine and offers a practical alternative to the original formula.</p>
83 Budget

L-Theanine 100 mg

California Gold Nutrition
<p>A lower serving cost comes with 100 mg of clearly stated l-theanine. The ingredient profile remains focused on theanine and offers a practical alternative to the original formula.</p>
85 Value

L-Theanine 200 mg

California Gold Nutrition
<p>200 mg of clearly stated L-theanine is paired with favorable serving-level value in the supplied data. The ingredient profile remains focused on theanine and offers a practical alternative to the original formula.</p>
85 Value

L-Theanine 100 mg

NOW
<p>100 mg of clearly stated L-theanine is paired with favorable serving-level value in the supplied data. The ingredient profile remains focused on theanine and offers a practical alternative to the original formula.</p>
84 Value

Suntheanine L-Theanine 125 mg

Natural Factors Stress-Relax
<p>250 mg of clearly identified branded L-theanine is paired with favorable serving-level value in the supplied data. The branded source provides clearer ingredient identity than the original generic theanine listing.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis.
    Bulman A; D'Cunha NM; Marx W; Turner M; McKune A; Naumovski N · Sleep medicine reviews · 2025
    Meta-analysis897 participants19 studies pooledSleep Support forTheanine
  2. The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review.
    Williams JL; Everett JM; D'Cunha NM; Sergi D; Georgousopoulou EN; Keegan RJ; McKune AJ; Mellor DD; Anstice N; Naumovski N · Plant foods for human nutrition (Dordrecht, Netherlands) · 2020
    Systematic review9 studies pooledStress Relief Mood Support forTheanine
  3. L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial.
    Sarris J; Byrne GJ; Cribb L; Oliver G; Murphy J; Macdonald P; Nazareth S; Karamacoska D; Galea S; Short A; Ee C; Birling Y; Menon R; Ng CH · Journal of psychiatric research · 2020
    Randomized trial46 participantsStress Relief Sleep Support forTheanine
  4. Promising, but Not Completely Conclusive-The Effect of l-Theanine on Cognitive Performance Based on the Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Clinical Trials.
    Mátyus RO; Szikora Z; Bodó D; Vargáné Szabó B; Csupor É; Csupor D; Tóth B · Journal of clinical medicine · 2025
    Meta-analysis148 participants5 studies pooledMental Focus Cognitive Support forTheanine
  5. Cognitive and affective effects of L-Theanine: a systematic review and meta-analysis of 31 randomized trials.
    Gerolymos C; Saddier E; Boyer L; Fond G · Molecular psychiatry · 2026
    Meta-analysis1,168 participants31 studies pooledMood Support Productivity Boost forTheanine
  6. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial.
    Hidese S; Ogawa S; Ota M; Ishida I; Yasukawa Z; Ozeki M; Kunugi H · Nutrients · 2020
    Randomized trial30 participantsBrain Health Cognitive Support Sleep Support forTheanine
  7. 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.
    Evans M; McDonald AC; Xiong L; Crowley DC; Guthrie N · Neurology and therapy · 2021
    Randomized trialBrain Health Stress Relief forTheanine
  8. 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.
    Payne ER; Aceves-Martins M; Dubost J; Greyling A; de Roos B · Nutrition reviews · 2025
    Meta-analysis50 studies pooledBrain Health Cognitive Support Mental Focus forTheanine
  9. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task.
    Foxe JJ; Morie KP; Laud PJ; Rowson MJ; de Bruin EA; Kelly SP · Neuropharmacology · 2012
    Randomized trial27 participantsBrain Health Cognitive Support forTheanine
  10. Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study.
    Baba Y; Inagaki S; Nakagawa S; Kaneko T; Kobayashi M; Takihara T · Journal of medicinal food · 2021
    Randomized trialBrain Health Mental Focus Productivity Boost forTheanine
  11. Dose-response effect of L-theanine on psychomotor speed, sustained attention, and inhibitory control: a double-blind, placebo-controlled, crossover study.
    Dassanayake TL; Wijesundara D; Kahathuduwa CN; Weerasinghe VS · Nutritional neuroscience · 2023
    Randomized trial32 participantsCognitive Support forTheanine
  12. Acute effects of theanine, caffeine and theanine-caffeine combination on attention.
    Kahathuduwa CN; Dassanayake TL; Amarakoon AMT; Weerasinghe VS · Nutritional neuroscience · 2018
    Clinical trial20 participantsCognitive Support Mental Focus forTheanine
  13. Safety and Efficacy of AlphaWave® L-Theanine Supplementation for 28 Days in Healthy Adults with Moderate Stress: A Randomized, Double-Blind, Placebo-Controlled Trial.
    Moulin M; Crowley DC; Xiong L; Guthrie N; Lewis ED · Neurology and therapy · 2024
    Randomized trial30 participantsMental Focus Productivity Boost Stress Relief forTheanine
  14. Effect of L-theanine on selective attention in a traffic-related reaction task in sleep-deprived young adults: a double-blind placebo-controlled, crossover study.
    Karunaratne UW; Dassanayake TL · Nutritional neuroscience · 2025
    Randomized trial24 participantsMental Focus forTheanine
  15. l-theanine adjunct to sertraline for major depressive disorder: A randomized, double-blind, placebo-controlled clinical trial.
    Shamabadi A; Kafi F; Arab Bafrani M; Asadigandomani H; A Basti F; Akhondzadeh S · Journal of affective disorders · 2023
    Randomized trial60 participantsMood Support forTheanine
  16. L-theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder: an 8-week, randomized, double-blind, placebo-controlled, 2-center study.
    Ritsner MS; Miodownik C; Ratner Y; Shleifer T; Mar M; Pintov L; Lerner V · The Journal of clinical psychiatry · 2011
    Randomized trial60 participantsMood Support Stress Relief forTheanine
  17. Comparison of the effects of two amino acids, Gamma-aminobutyric acid (GABA) and L-theanine, on sedation, anxiety, and cognition in preoperative surgical patients - A randomized controlled study.
    Deshpande SS; Kurdi M; Baiju A; Athira AS; Sarasamma AG; Gangadharan AK · Journal of anaesthesiology, clinical pharmacology · 2025
    Randomized trial168 participantsMood Support Stress Relief forTheanine
  18. Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary α-amylase activity, trait anxiety and subjective stress.
    Unno K; Tanida N; Ishii N; Yamamoto H; Iguchi K; Hoshino M; Takeda A; Ozawa H; Ohkubo T; Juneja LR; Yamada H · Pharmacology, biochemistry, and behavior · 2014
    Randomized trial20 participantsMood Support forTheanine
  19. Effects of L-theanine on cognition, mood and sleep: evidence from human trials.
    Cotter J; Kilpatrick HE · Frontiers in nutrition · 2026
    Narrative reviewProductivity Boost forTheanine
  20. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together.
    Rogers PJ; Smith JE; Heatherley SV; Pleydell-Pearce CW · Psychopharmacology · 2008
    Randomized trial48 participantsProductivity Boost forTheanine
  21. Comparison Between Efficacy of Oral Melatonin and Oral L-theanine in Improving Sleep in Cancer Patients Suffering From Insomnia: A Randomised Double-blinded Placebo-controlled Study.
    Kurdi MS; As A; Ladhad DA; Mitragotri MV; Baiju A · Indian journal of palliative care · 2024
    Randomized trial120 participantsSleep Support forTheanine
  22. In Search of a Safe Natural Sleep Aid.
    Rao TP; Ozeki M; Juneja LR · Journal of the American College of Nutrition · 2016
    Narrative reviewSleep Support forTheanine
  23. Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial.
    White DJ; de Klerk S; Woods W; Gondalia S; Noonan C; Scholey AB · Nutrients · 2016
    Randomized trial34 participantsStress Relief forTheanine