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ZenMind

NutriCology
4.6
★ ★ ★ ★ ★
(230 ratings)
Theanine 200 mg
GABA 550 mg
Product Image
Score83
A strong branded-theanine formula with enough GABA to deepen the calming emphasis. It suits relaxation better than broad cognitive enhancement.
How scoring works
Quantity:60 Capsule(s) • (30 servings)
Goals:
Stress Relief
Sleep Support
Brain Health
Productivity Boost
Mental Focus
Mood Support
Cognitive Support

Score 83

A strong branded-theanine formula with enough GABA to deepen the calming emphasis. It suits relaxation better than broad cognitive enhancement.
How scoring works
$20.82($0.69 per serving)
Vitacost
$ 20.82
Amazon
$ 44.19
Pure Formulas
$ 44.19
iHerb
$ 41.19
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Analysis

Suntheanine supplies a substantial amount of a well-characterized L-theanine source. It fits relaxed attention and stress-related focus without relying on a stimulant.

GABA contributes a strong label amount, but its effects after swallowing vary because access to the brain is uncertain. Together, the ingredients favor relaxation more than memory, processing speed, or mental energy.

Both doses are clear and no unrelated actives dilute the formula. The serving offers solid value for branded theanine, though the combined calming amount can be too sedating before daytime tasks.

Who is it for
  • Adults seeking branded theanine at a substantial amount
  • People who want stimulant-free calm support
  • Users whose focus suffers when tension is high
Best for
  • Calm attention
  • Evening relaxation
  • Focused two-ingredient supplementation

Pros

  • Uses branded Suntheanine
  • Provides 200 mg L-theanine
  • Provides 550 mg GABA
  • Offers clear active-dose disclosure

Cons

  • GABA source is not characterized
  • Oral GABA effects are less dependable
  • Formula is narrow for broad cognitive needs
  • May feel too calming for daytime productivity

Warnings

  • The combined 200 mg theanine and 550 mg GABA amounts may cause drowsiness; learn the effect before driving.
  • GABA may add to sedation from alcohol, benzodiazepines, sleep medicines, or other sedatives.
  • Users who need quick reactions or sustained alertness should avoid taking the formula immediately beforehand.

Nutrient quality

90 Highest impact

Branded L-theanine and a substantial GABA amount create a focused calming formula. Oral GABA has uncertain brain availability, while the branded theanine improves source confidence.

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Ingredient transparency

79 High impact

Both active amounts are individually stated and no blend hides the formula. The branded theanine is specific, but GABA sourcing, other ingredients, and complete intake directions remain undisclosed.

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Customer satisfaction

70 High impact

The supplied satisfaction average is strong and has large supporting volume. No specific experience details are provided to assess repeated complaints or alignment with the intended use.

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Value for money

90 Highest impact

Two substantial, fully disclosed calming actives provide clear functional value. A reasonable serving cost determines whether that formula quality compares well with simpler alternatives.

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Report analysis

Goals

Stress Relief
Impact
Highest effect
A- Goal FitA+ Strength of SupportB CoverageA+ Formula Quality
GABA · 550 mgTheanine · 200 mg

Branded L-theanine and GABA form a strongly aligned calming pair for relaxed attention and inhibitory signaling. Evidence is more consistent for theanine because oral GABA effects vary.

Both actives are fully disclosed at substantial amounts, and Suntheanine adds useful source quality. The 550 mg GABA amount may cause drowsiness, especially with alcohol, sedatives, or before driving.

Study evidence
GABA Supportive 6 studies
Theanine Supportive 16 studies
Sleep Support
Impact
Highest effect
B+ Goal FitA Strength of SupportB- CoverageA+ Formula Quality
Theanine · 200 mg

L-theanine supports relaxation without acting as a strong sedative, while GABA may add calming effects. The 200 mg theanine and 550 mg GABA amounts are clearly stated with a branded theanine source.

Oral GABA has uncertain access to the brain, so its direct contribution to sleep remains less dependable. The combination may cause drowsiness, especially with alcohol or sedative medicines, so users should learn its effects before driving.

Study evidence
GABA Supportive 4 studies
Theanine Supportive 8 studies
Brain Health
Impact
Highest effect
B- Goal FitA+ Strength of SupportB- CoverageA+ Formula Quality

Suntheanine and GABA provide a focused calm-attention combination that may help when stress impairs concentration. Evidence is stronger for L-theanine than for swallowed GABA as a cognitive aid.

Both amounts are substantial, and the branded L-theanine source strengthens quality confidence. The 550 mg GABA amount may cause drowsiness, especially with alcohol or other sedating substances.

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

Suntheanine supplies a meaningful L-theanine amount that may support calm attention during mentally demanding work. GABA broadens the calming effect but is less reliable as a cognitive aid.

The branded theanine form and both active amounts are clearly disclosed. The combination of 200 mg L-theanine and 550 mg GABA may cause drowsiness, so it may be a poor fit before driving or alertness-dependent tasks.

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

Branded L-theanine provides a high-quality base for calm attention, while GABA adds deeper relaxation support. The pairing may help stress-related distraction but is less suited to users seeking stimulation.

Both actives are fully disclosed and supplied at substantial amounts. The combination of 200 mg L-theanine and 550 mg GABA may cause drowsiness before driving or when combined with alcohol or sedating medicines.

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

200 mg Suntheanine and 550 mg GABA create a focused calming formula that may reduce tension. The combination is more relevant to short-term relaxation than to sustained mood regulation.

Suntheanine provides a branded theanine source, while the GABA source is not characterized. The combined calming dose may cause drowsiness, so its effect should be known before driving or other alertness-dependent tasks.

Study evidence
GABA Supportive 12 studies
Theanine Supportive 12 studies
Cognitive Support
Impact
High effect
B- Goal FitB Strength of SupportD+ CoverageC+ Formula Quality
Theanine · 200 mg

The formula may support attention or calm focus through stimulant, L-theanine, or stress-related pathways. Its usefulness depends on the exact active amounts and whether alertness or relaxation is the intended outcome.

It does not provide broad memory, membrane, or long-term neuroprotective support. Multi-ingredient versions also include several components with limited direct cognitive relevance.

Study evidence
Theanine Supportive 25 studies

Ingredients

IngredientAmount per serving
GABA
550 mg
Suntheanine L-Theanine
200 mg
Adults 18–50
Report overview
Theanine · 200 mg OverallScore96
A+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyB+ Value

Suntheanine provides a clearly identified, high-purity L-theanine source at an effective serving amount. Full dose disclosure makes the formula easy to assess, and the cost is competitive for the amount supplied. The combination of 200 mg L-theanine and 550 mg GABA may cause drowsiness in some people, so it may be unsuitable before driving or other tasks requiring alertness.

GABA · 550 mg OverallScore75
B- Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyD- Value

The clearly disclosed 550 mg GABA dose fits the intended range and may cause drowsiness, so avoid driving until its effect is known. A vegetarian capsule offers a practical delivery format, though the GABA source lacks a branded fermentation claim. Cost per serving is high for standard unbranded GABA.

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Sources

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

  1. Oral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks.
    Yoto A; Murao S; Motoki M; Yokoyama Y; Horie N; Takeshima K; Masuda K; Kim M; Yokogoshi H · Amino acids · 2012
    Randomized trial63 participantsStress Relief Mood Support forGABA
  2. GABA Supplementation, Increased Heart-Rate Variability, Emotional Response, Sleep Efficiency and Reduced Depression in Sedentary Overweight Women Undergoing Physical Exercise: Placebo-Controlled, Randomized Clinical Trial.
    Guimarães AP; Seidel H; Pires LVM; Trindade CO; Baleeiro RDS; Souza PM; Silva FGDE; Coelho DB; Becker LK; Oliveira EC · Journal of dietary supplements · 2024
    Randomized trial30 participantsStress Relief Sleep Support forGABA
  3. 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 participantsStress Relief forGABA Mood Support Stress Relief forTheanine
  4. 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
  5. 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
  6. 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
  7. Effect of Combined Ingestion of L-Theanine and L-Arginine for Short-Term Psychological Stress in Young Adults: A Randomized Placebo-Controlled Study.
    Furushima D; Sugiyama I; Nomura Y; Unno K; Yamada H · Journal of nutritional science and vitaminology · 2023
    Randomized trial120 participantsStress 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 pooledMental Focus Brain Health Cognitive Support forTheanine
  9. Acute effects of theanine, caffeine and theanine-caffeine combination on attention.
    Kahathuduwa CN; Dassanayake TL; Amarakoon AMT; Weerasinghe VS · Nutritional neuroscience · 2018
    Clinical trial20 participantsMental Focus Cognitive Support forTheanine
  10. 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
  11. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood.
    Dodd FL; Kennedy DO; Riby LM; Haskell-Ramsay CF · Psychopharmacology · 2016
    Randomized trial24 participantsMental Focus forTheanine
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. Peripartum neuroactive steroid and γ-aminobutyric acid profiles in women at-risk for postpartum depression.
    Deligiannidis KM; Kroll-Desrosiers AR; Mo S; Nguyen HP; Svenson A; Jaitly N; Hall JE; Barton BA; Rothschild AJ; Shaffer SA · Psychoneuroendocrinology · 2017
    Cohort study56 participantsMood Support forGABA
  19. The role of neurotransmitters in mediating the relationship between brain alterations and depressive symptoms in patients with inflammatory bowel disease.
    Wang J; Liu G; Xu K; Ai K; Huang W; Zhang J · Human brain mapping · 2023
    Case-control study69 participantsMood Support forGABA
  20. Occipital gamma-aminobutyric acid and glutamate-glutamine alterations in major depressive disorder: An mrs study and meta-analysis.
    Truong V; Cheng PZ; Lee HC; Lane TJ; Hsu TY; Duncan NW · Psychiatry research. Neuroimaging · 2021
    Observational studyMood Support forGABA
  21. Systematic review of gamma-aminobutyric-acid inhibitory deficits across the reproductive life cycle.
    Vigod SN; Strasburg K; Daskalakis ZJ; Blumberger DM · Archives of women's mental health · 2014
    Systematic review11 studies pooledMood Support forGABA
  22. 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
  23. 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
  24. 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 pooledMood Support forTheanine
  25. 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
  26. 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
  27. 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
  28. 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
  29. Safety and Efficacy of Gamma-Aminobutyric Acid from Fermented Rice Germ in Patients with Insomnia Symptoms: A Randomized, Double-Blind Trial.
    Byun JI; Shin YY; Chung SE; Shin WC · Journal of clinical neurology (Seoul, Korea) · 2020
    Randomized trial40 participantsSleep Support forGABA
  30. Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems.
    Imafuku F; Yamamoto K; Tanaka E; Aoki R; Nishino S · Nutrients · 2023
    Randomized trial160 participantsSleep Support forGABA
  31. Reduced γ-aminobutyric acid in occipital and anterior cingulate cortices in primary insomnia: a link to major depressive disorder?
    Plante DT; Jensen JE; Schoerning L; Winkelman JW · Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2012
    Case-control study40 participantsSleep Support forGABA
  32. 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
  33. 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
  34. 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
  35. Relieving occupational fatigue by consumption of a beverage containing γ-amino butyric acid.
    Kanehira T; Nakamura Y; Nakamura K; Horie K; Horie N; Furugori K; Sauchi Y; Yokogoshi H · Journal of nutritional science and vitaminology · 2011
    Clinical trial30 participantsStress Relief forGABA
  36. Cortical gamma-aminobutyric acid and glutamate in posttraumatic stress disorder and their relationships to self-reported sleep quality.
    Meyerhoff DJ; Mon A; Metzler T; Neylan TC · Sleep · 2014
    Case-control study45 participantsStress Relief forGABA