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Theanine 200 mg

Jarrow Formulas
4.7
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(6241 ratings)
Theanine 200 mg
Product Image
Score83
A substantial 200 mg one-capsule serving works well for focused calm and relaxation. It lacks branded sourcing and broader cognitive or sleep support.
How scoring works
Quantity:60 Veggie Cap(s) • (60 servings)
Goals:
Stress Relief
Sleep Support
Cognitive Support
Productivity Boost
Mental Focus
Mood Support
Brain Health

Score 83

A substantial 200 mg one-capsule serving works well for focused calm and relaxation. It lacks branded sourcing and broader cognitive or sleep support.
How scoring works

Also available as

1 option
100.00mg • 60 Veggie Cap(s) servings Theanine 100 mg • 60 Veggie Cap(s) • 60 servings $10.00 ($0.16 per serving)
$20.99($0.34 per serving)
Vitacost
$ 25.79
Pure Formulas
$ 20.99
Daily Vita
$ 22.99
iHerb
$ 26.60
Walmart
$ 28.73
Amazon
$ 20.99
Report prices

Analysis

A 200 mg L-theanine capsule supplies a substantial amount for relaxation and stress-related distraction. The active L-isomer and exact amount are clearly disclosed in a lean formula.

It is well suited to acute stress, calm attention, and pre-sleep mental tension. Standalone effects on alertness may be subtle, and the product does not address memory, circadian timing, or broad mood support.

One capsule per serving and good active efficiency make the product easy to use consistently. No branded source or additional purity standard is supplied.

Who is it for
  • Adults seeking a higher theanine amount
  • People whose focus is disrupted by tension
  • Users who want one capsule per serving
Best for
  • Acute stress support
  • Calm mental focus
  • Relaxation before bed

Pros

  • Substantial 200 mg amount
  • One-capsule serving
  • Clearly identified L-isomer
  • Good active efficiency

Cons

  • Generic source
  • No alertness ingredient
  • 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

87 Highest impact

Formula quality provides strong support for the product positioning. Dose-adjusted serving value appears reasonable, 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

The higher L-theanine amount offers focused, well-dosed support for calm attention without a stimulant. It is closely aligned with acute stress management and is unlikely to be broadly sedating.

Pathway coverage remains narrow because the formula contains only one active. The exact L-isomer and dose are transparent, although branded-source and purity details are missing.

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

L-theanine may help quiet pre-sleep mental tension without the heavy feel of a sedative. The 200 mg amount sits near the upper end of a useful range and is clearly disclosed in one capsule.

The source is generic and carries no additional purity or branded-form assurance. The formula is focused on relaxation rather than circadian timing or support for staying asleep.

Study evidence
Theanine Supportive 8 studies
Cognitive Support
Cognitive Support
Impact
Highest effect
B+ Goal FitA Strength of SupportC- CoverageA+ Formula Quality
Theanine · 200 mg

The 200 mg L-theanine serving provides substantial support for calm focus in a clearly identified active form. Full dose disclosure makes the formula straightforward to assess.

Its narrow mechanism does not cover memory, circulation, or brain-cell structure. A generic source without added purity verification is the main quality limitation.

Study evidence
Theanine Supportive 25 studies
Productivity Boost
Productivity Boost
Impact
Highest effect
B- Goal FitA+ Strength of SupportD+ CoverageA+ Formula Quality
Theanine · 200 mg

L-theanine at 200 mg may support calm attention and reduce distraction from tension. Evidence is more consistent when it is paired with caffeine than when used alone for productivity.

The amount is well aligned with commonly studied use and is fully disclosed. The single-active design is clean but lacks an alerting ingredient or a second productivity pathway.

Study evidence
Theanine Supportive 5 studies
Mental Focus
Mental Focus
Impact
Highest effect
B Goal FitA- Strength of SupportC- CoverageA+ Formula Quality
Theanine · 200 mg

L-theanine at a substantial amount may help calm distraction and smooth stress-related mental tension. Taken alone, it is not a strong alertness enhancer, though human evidence supports relaxation without marked sedation.

The active form and exact amount are fully disclosed in a clean single-ingredient product. Missing branded sourcing and purity testing are the main quality limitations.

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

L-theanine is supplied near the upper end of its preferred range and directly supports calm alertness. The label clearly identifies the L-isomer and full amount, while branded-source and added purity details are missing.

Its strength lies in focused situational stress support rather than broad or long-term mood regulation. The formula is clean and substantial for its target, but it lacks additional neurotransmitter, adaptogenic, or neuroprotective pathways.

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

L-theanine may support calm attention and reduce stress-related distraction at a substantial amount. Clear L-isomer disclosure makes the serving easy to assess.

The single-active design lacks memory, energy, and structural brain support. No branded source or independent purity testing is shown.

Study evidence
Theanine Supportive 17 studies

Ingredients

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

The clearly identified L-isomer and individually disclosed 200 mg amount support confident dose assessment. The serving is near the upper end of the preferred range, while the generic source lacks branded-form or purity verification. Cost efficiency remains competitive for the active amount delivered.

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. 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