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Theanine 100 mg

Jarrow Formulas
4.7
★ ★ ★ ★ ★
(5111 ratings)
Theanine 100 mg
Product Image
Score82
A simple 100 mg capsule offers efficient, adjustable calm-focus support. Generic sourcing and single-pathway coverage are its main limits.
How scoring works
Quantity:60 Veggie Cap(s) • (60 servings)
Goals:
Stress Relief
Sleep Support
Cognitive Support
Mood Support
Mental Focus
Brain Health
Productivity Boost

Score 82

A simple 100 mg capsule offers efficient, adjustable calm-focus support. Generic sourcing and single-pathway coverage are its main limits.
How scoring works

Also available as

1 option
200.00mg • 60 Veggie Cap(s) servings Theanine 200 mg • 60 Veggie Cap(s) • 60 servings $20.99 ($0.34 per serving)
$10.00($0.16 per serving)
Pure Formulas
$ 11.99
Vitacost
$ 15.17
Vitacost
$ 15.17
Daily Vita
$ 12.99
Amazon
$ 11.99
iHerb
$ 15.59
Daily Vita
$ 10.00
Report prices

Analysis

A 100 mg L-theanine capsule provides a practical starting amount for calm attention and situational stress. The single-active design is transparent, streamlined, and easy to adjust within a routine.

It fits users who want relaxation without a heavy sedative or stimulant effect. Effects on productivity, memory, mood, and sleep are likely narrow because no complementary pathway is included.

One capsule per serving, strong active efficiency, and extensive aggregate feedback support regular use. The generic source lacks a branded purity signal, although the active form and amount are clear.

Who is it for
  • Adults starting with a moderate theanine amount
  • People seeking calm focus
  • Users who prefer one-capsule servings
Best for
  • Situational stress relief
  • Mild pre-sleep relaxation
  • Calm attention

Pros

  • Useful 100 mg amount
  • One capsule per serving
  • Single-active formula
  • Strong active-ingredient value

Cons

  • Generic theanine source
  • No complementary focus ingredient
  • Limited sleep and mood pathway coverage

Nutrient quality

90 Highest impact

L-theanine is a defined amino acid, although no branded source or purity marker is supplied. The L-theanine amount is practical for moderate daily support.

.

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

85 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 · 100 mg

A clearly disclosed L-theanine amount provides focused support for calm attention without adding a stimulant. The serving sits in a commonly used range for acute relaxation.

The simple formula offers little coverage beyond theanine-mediated neurotransmitter and alpha-wave effects. No branded source or independent purity detail is provided, but the active form and amount are easy to assess.

Study evidence
Theanine Supportive 16 studies
Sleep Support
Sleep Support
Impact
Highest effect
B Goal FitA Strength of SupportC+ CoverageA Formula Quality
Theanine · 100 mg

L-theanine supports a calm mental state without acting as a heavy sedative, which may help when racing thoughts delay sleep. The 100 mg amount fits a meaningful range and is clearly disclosed in one capsule.

The generic source lacks branded purity assurance, and the formula does not directly regulate circadian timing or nighttime maintenance. Its focused design is best suited to relaxation-related sleep difficulty.

Study evidence
Theanine Supportive 8 studies
Cognitive Support
Cognitive Support
Impact
High effect
B Goal FitA- Strength of SupportC- CoverageA+ Formula Quality
Theanine · 100 mg

The 100 mg L-theanine serving is well aligned with calm focus and uses the clearly identified active isomer. The amount is fully disclosed and sits in a commonly used range.

L-theanine mainly supports relaxed attention, so it offers limited coverage for memory or long-term brain structure. The generic source also lacks added purity or branded-ingredient verification.

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

L-theanine provides focused support for calm alertness at a preferred serving amount. The L-isomer and exact dose are clearly identified, though no branded source or added purity verification is provided.

The formula may help with situational stress more directly than persistent mood regulation. It is streamlined and well dosed, but it does not address neurotransmitter precursors, broader stress adaptation, or neuroprotective support.

Study evidence
Theanine Supportive 12 studies
Mental Focus
Mental Focus
Impact
High effect
B Goal FitA- Strength of SupportC- CoverageA+ Formula Quality
Theanine · 100 mg

L-theanine can promote calm attention and may be especially useful when stress or caffeine causes distraction. Its direct focus effect is modest when taken alone, but human evidence supports relaxation without heavy sedation.

The L-isomer and exact amount are clearly disclosed in a simple formula. No branded source or purity verification is shown, and the product lacks a complementary alertness ingredient.

Study evidence
Theanine Supportive 19 studies
Brain Health
Brain Health
Impact
High effect
B- Goal FitB Strength of SupportD+ CoverageA Formula Quality

L-theanine may support calm attention and reduce mental tension without sedation. The exact L-isomer amount sits at the low end of the useful range.

The product is focused but does not address memory, brain energy, or structural support. No branded source or independent purity testing is provided.

Study evidence
Theanine Supportive 17 studies
Productivity Boost
Productivity Boost
Impact
High effect
C Goal FitB+ Strength of SupportD- CoverageA+ Formula Quality
Theanine · 100 mg

L-theanine at 100 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 useful but sits at the lower end of commonly studied use. The single-active design is clean but lacks an alerting ingredient or a second productivity pathway.

Study evidence
Theanine Supportive 5 studies

Ingredients

IngredientAmount per serving
L-Theanine
100 mg
Gluten Free Adults 18–50 Vegan Dairy Free Vegetarian
Report overview
Theanine · 100 mg OverallScore88
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyB+ Value

The clearly identified L-isomer and individually disclosed 100 mg amount make the formula easy to assess for calming or focus support. The dose sits in the preferred range, but no branded source or added purity verification is provided. Cost efficiency is 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