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L-Theanine 200 mg

Vital Nutrients
4.9
★ ★ ★ ★ ★
(26 ratings)
Theanine 200 mg
Product Image
Score81
A simple, substantial theanine capsule with good value, traded against limited source-quality assurance.
How scoring works
Quantity:60 Capsule(s) • (60 servings)
Goals:
Stress Relief
Sleep Support
Mental Focus
Mood Support
Brain Health
Productivity Boost
Cognitive Support

Score 81

A simple, substantial theanine capsule with good value, traded against limited source-quality assurance.
How scoring works
$36.90($0.61 per serving)
Pure Formulas
$ 38.99
iHerb
$ 36.90
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Analysis

The single capsule delivers a substantial L-theanine amount in the preferred range. It offers focused support for calm attention and stress-related tension.

No branded source, purity claim, or testing detail is given. The formula also covers only one pathway, so broader brain or sleep goals may need other approaches.

Clear dosing and competitive cost make it easy to use regularly. It best suits people who want straightforward generic theanine.

Who is it for
  • Adults seeking substantial L-theanine
  • Users wanting a simple one-capsule formula
  • People focused on calm attention
Best for
  • Situational stress
  • Calm focus
  • Evening relaxation

Pros

  • Preferred-range amount
  • One-capsule serving
  • Single active ingredient
  • Competitive value

Cons

  • Generic source
  • No purity claim
  • No branded-form assurance
  • Limited pathway coverage

Warnings

  • L-theanine may cause drowsiness
  • Combining with sedatives or alcohol may increase sleepiness
  • Antihypertensive users should monitor for lightheadedness

Nutrient quality

93 Highest impact

L-theanine is appropriate, but no branded source or purity claim is supplied. The active amount is meaningful for calm-focus and relaxation use.

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Ingredient transparency

84 Highest impact

Every listed active has a specific amount, which makes the core formula straightforward to assess. The supplied data omits a complete excipient list and full intake directions.

.

Customer satisfaction

61 Moderate impact

The supplied aggregate satisfaction signal is favorable. Limited feedback volume and absent narrative evidence leave the experience less certain.

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Value for money

81 Highest impact

The meaningful amount supports quality, though generic sourcing weakens the premium case. Serving-level value is fair for a dedicated single-active capsule.

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Report analysis

Goals

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

A substantial L-theanine amount supports calm attention without acting as a heavy sedative. Human evidence supports relaxation and a milder stress response in some settings.

The L-isomer and exact amount are clear, though no branded source or purity verification is provided. The focused design provides strong depth but no adaptogen or mineral pathway.

Study evidence
Theanine Supportive 16 studies
Sleep Support
Sleep Support
Impact
Highest effect
B Goal FitA Strength of SupportC- CoverageA+ Formula Quality
Theanine · 200 mg

A substantial L-theanine amount provides focused support for mental relaxation. The simple vegetarian capsule makes the active dose easy to assess.

Human evidence is more consistent for calming than for direct improvement in sleep duration. The unbranded source lacks additional purity or identity assurance.

Study evidence
Theanine Supportive 8 studies
Mental Focus
Mental Focus
Impact
High effect
B+ Goal FitB+ Strength of SupportC- CoverageA Formula Quality
Theanine · 200 mg

L-theanine provides a focused option for calm attention and mental composure. Its single-pathway design does not add alertness, neurotransmitter precursors, or adaptogenic breadth.

The 200 mg amount is well aligned and clearly disclosed. The label does not provide a branded source, purity claim, or independent testing evidence.

Study evidence
Theanine Supportive 19 studies
Mood Support
Mood Support
Impact
High effect
B Goal FitB+ Strength of SupportC- CoverageA+ Formula Quality

L-theanine directly supports calm attention and is provided at a meaningful focused amount. Human evidence is more convincing for relaxation and acute stress than for persistent low mood.

The single-active formula provides strong depth in one calming pathway without broader mood coverage. The amount is clear, though no branded source or purity verification is supplied.

Study evidence
Theanine Supportive 12 studies
Brain Health
Brain Health
Impact
High effect
B Goal FitB+ Strength of SupportC CoverageA+ Formula Quality

The single-ingredient formula is well suited to calm focus and stress-related attention support. A clearly disclosed L-theanine amount matches common supplemental use.

It targets one narrow pathway and provides no caffeine partner or other cognitive active. The focused design suits users who want simple relaxation support without a complex stack.

Study evidence
Theanine Supportive 17 studies
Productivity Boost
Productivity Boost
Impact
High effect
B- Goal FitA- Strength of SupportD+ CoverageA+ Formula Quality
Theanine · 200 mg

A substantial L-theanine serving may support calm concentration, especially when paired with caffeine from another source. Stand-alone productivity benefits are less predictable because the formula does not increase alertness or mental energy.

The exact amount and active identity are clear, though no branded source or purity testing is disclosed. The streamlined capsule contains no unrelated active ingredients.

Study evidence
Theanine Supportive 5 studies
Cognitive Support
Cognitive Support
Impact
High effect
B Goal FitB+ Strength of SupportC- CoverageA Formula Quality
Theanine · 200 mg

L-theanine provides focused support for calm attention and stress-related concentration. The single-ingredient formula is narrow but reaches a meaningful amount.

The exact dose is disclosed in a simple capsule. Missing branded sourcing or purity testing is the main quality limitation.

Study evidence
Theanine Supportive 25 studies

Ingredients

IngredientAmount per serving
L-Theanine
200 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Theanine · 200 mg OverallScore88
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyB+ Value

The clearly disclosed 200 mg L-theanine serving is well aligned with focused calming or attention support. No branded source, purity claim, or independent testing is provided. Competitive cost efficiency is a meaningful practical strength.

View ingredientView products
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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. Its disclosed ingredient profile aligns more closely with focused theanine use than 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. Its disclosed ingredient profile aligns more closely with focused theanine use than 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. Its disclosed ingredient profile aligns more closely with focused theanine use than 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. Its disclosed ingredient profile aligns more closely with focused theanine use than 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 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
  2. 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 trialStress Relief Brain Health 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. 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 participantsStress Relief Mental Focus Productivity Boost forTheanine
  5. 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 forTheanine
  6. 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 trialMental Focus Brain Health Productivity Boost forTheanine
  7. 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 participantsMental Focus Productivity Boost forTheanine
  8. 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
  9. 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
  10. 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
  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. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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 pooledProductivity Boost 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. 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
  21. 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
  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