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200 mg of Zen

Allergy Research Group
4.8
★ ★ ★ ★ ★
(31 ratings)
Theanine 200 mg
GABA 550 mg
Product Image
Score76
Branded, well-dosed theanine is the main strength of this simple calming formula. GABA may deepen relaxation, but it also makes alertness and value trade-offs more important.
How scoring works
Quantity:60 Capsule(s) • (30 servings)
Goals:
Sleep Support
Stress Relief
Mood Support
Mental Focus
Cognitive Support
Brain Health
Productivity Boost

Score 76

Branded, well-dosed theanine is the main strength of this simple calming formula. GABA may deepen relaxation, but it also makes alertness and value trade-offs more important.
How scoring works
$44.19($1.47 per serving)
Pure Formulas
$ 44.19
Vitacost
$ 44.19
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Analysis

Suntheanine provides 200 mg of a well-characterized L-theanine source for calm attention and relaxation. The branded form improves identity and quality confidence compared with generic theanine.

GABA adds 550 mg and reinforces the wind-down focus, although oral GABA has uncertain access to the brain. The pairing is better suited to tension-related distraction or bedtime relaxation than memory or mental energy.

Both active amounts are stated and the short formula avoids padding. The serving cost is high, and the substantial calming load may feel sedating for some daytime users.

Who is it for
  • Adults wanting branded L-theanine
  • People seeking non-stimulant relaxation support
  • Users whose focus is disrupted by tension
Best for
  • Evening wind-down routines
  • Calm attention
  • Branded theanine supplementation

Pros

  • Uses branded Suntheanine
  • Provides 200 mg L-theanine
  • Provides 550 mg GABA
  • Fully discloses both active amounts

Cons

  • High serving cost
  • Oral GABA effects are less predictable
  • Narrow formula does not cover memory or mental-energy pathways
  • Requires two capsules per serving

Warnings

  • The combined L-theanine and GABA amounts may cause drowsiness, so learn the effect before driving or operating equipment.
  • GABA may add to the effects of alcohol, benzodiazepines, sleep medicines, and other sedatives.
  • The relaxation-focused combination may be a poor fit immediately before alertness-dependent work.

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

67 High impact

The supplied satisfaction average is strong and has moderate 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

64 Moderate impact

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

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Report analysis

Goals

Sleep Support
Sleep Support
Impact
Highest effect
A- Goal FitA+ Strength of SupportB CoverageA+ Formula Quality
Theanine · 200 mg

Suntheanine and a substantial GABA amount provide a focused two-part relaxation formula. Theanine is well supported for reducing mental tension, while oral GABA has less certain central nervous system effects.

Both amounts are fully disclosed and sit within practical supplemental ranges. The narrow formula may help with winding down but does not directly address circadian timing or mineral support.

Study evidence
GABA Supportive 4 studies
Theanine Supportive 8 studies
Stress Relief
Stress Relief
Impact
Highest effect
A- Goal FitA Strength of SupportB- CoverageA+ Formula Quality
GABA · 550 mgTheanine · 200 mg

Suntheanine L-theanine at 200 mg and GABA at 550 mg create a direct, focused calming formula. Theanine has good human evidence for relaxed attention, and both amounts fall within useful ranges.

Oral GABA evidence is less consistent because brain availability remains uncertain, but the combination is logically constructed. The two-capsule formula avoids stimulants and unrelated ingredients.

Study evidence
GABA Supportive 6 studies
Theanine Supportive 16 studies
Mood Support
Mood Support
Impact
Highest effect
B+ Goal FitA Strength of SupportC CoverageA+ Formula Quality

A substantial dose of branded L-theanine creates a focused relaxation formula. GABA may add calming support, although its brain effects after oral use are less certain.

Full disclosure and clean dosing make the contribution easy to judge. The narrow design is coherent and free of padding but does not cover broader mood pathways.

Study evidence
GABA Supportive 12 studies
Theanine Supportive 12 studies
Mental Focus
Mental Focus
Impact
High effect
C Goal FitA Strength of SupportC+ CoverageB+ Formula Quality
Theanine · 200 mg

Suntheanine supplies a high-quality 200 mg L-theanine amount that may support calm attention. The clearly disclosed formula avoids an opaque blend.

A substantial GABA amount may increase relaxation but can also become sedating, which limits fit for active mental focus. The formula lacks an alertness or neurotransmitter-precursor pathway.

Study evidence
Theanine Supportive 19 studies
Cognitive Support
Cognitive Support
Impact
High effect
C Goal FitA- Strength of SupportC- CoverageA- Formula Quality
Theanine · 200 mg

Suntheanine may support calm attention and GABA adds a complementary relaxation signal. The formula is better suited to reducing tension than to memory or processing speed.

The branded theanine amount is well aligned and fully disclosed, while oral GABA has less certain brain availability. The combination may cause drowsiness in sensitive users, which matters before driving or other alertness-dependent tasks.

Study evidence
Theanine Supportive 25 studies
Brain Health
Brain Health
Impact
High effect
C Goal FitB+ Strength of SupportC- CoverageA Formula Quality

Branded Suntheanine provides focused support for calm attention, while GABA adds a second inhibitory-signaling ingredient. The formula is more useful for relaxation than for memory, neuronal structure, or mental energy.

Both actives are clearly disclosed at substantial amounts, and the branded theanine improves quality confidence. The two-ingredient design is coherent and free from obvious padding, though evidence for oral GABA is less consistent.

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

Theanine and GABA form a focused calming stack that may help concentration when tension is the main barrier. It does not provide alertness, memory support, or a neurotransmitter precursor for demanding work.

The 200 mg branded theanine amount is well supported for relaxation, while oral GABA has less certain brain availability. Both ingredients may increase drowsiness when combined with alcohol or sedating medicines.

Study evidence
Theanine Supportive 5 studies

Ingredients

IngredientAmount per serving
GABA
550 mg
Suntheanine L-Theanine
200 mg
Adults 18–50
Report overview
Theanine · 200 mg OverallScore84
A+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyF Value

Explicit L-theanine identity and Suntheanine branding provide strong isomer and purity confidence. The clearly disclosed amount falls within the optimal range for calm and focused support. Suntheanine strengthens quality confidence, but the dose-adjusted cost remains high.

View ingredientView products
GABA · 550 mg OverallScore72
B- Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyD- Value

The formula provides a clearly disclosed GABA dose within the preferred effective range. Its capsule delivery is practical, but the GABA source is unbranded and offers no premium production claim. A high serving cost limits value even with branded theanine included.

View ingredientView products
Loading alternative details
87 Performance

L-Theanine 100 mg

California Gold Nutrition
AlphaWave L-theanine provides a clearly disclosed 100 mg amount with branded ingredient assurance. The defined source and focused dose improve ingredient clarity over the original stack's high serving cost and limited satisfaction evidence. The focused formula omits GABA, but evidence for swallowed theanine is more direct than for swallowed GABA.
87 Performance

L-Theanine 200 mg Double Strength

Swanson
Branded Suntheanine supplies a substantial 200 mg amount in a focused capsule without unrelated actives. The defined source and focused dose improve ingredient clarity over the original stack's high serving cost and limited satisfaction evidence. The focused formula omits GABA, but evidence for swallowed theanine is more direct than for swallowed GABA.
85 Performance

Pharma GABA 250 mg

Natural Factors Stress-Relax
Fermented Pharma GABA provides a well-defined 250 mg amount in a focused formula with stronger source assurance than generic GABA. The defined source and focused dose improve ingredient clarity over the original stack's high serving cost and limited satisfaction evidence. Oral GABA has uncertain brain availability and may cause drowsiness, especially with alcohol, sleep aids, or other sedating products.
84 Budget

GABA

NOW
A substantial 500 mg GABA amount in a flexible liquid provides focused calming support at exceptionally low serving cost. Its lower serving cost improves affordability over the original stack's high serving cost and limited satisfaction evidence. Oral GABA has uncertain brain availability and may cause drowsiness, especially with alcohol, sleep aids, or other sedating products.
81 Budget

GABA Powder

Source Naturals Serene Science
A clearly disclosed 750 mg GABA amount provides a simple, adjustable powder at exceptionally low serving cost. Its lower serving cost improves affordability over the original stack's high serving cost and limited satisfaction evidence. Oral GABA has uncertain brain availability and may cause drowsiness, especially with alcohol, sleep aids, or other sedating products.
85 Budget

L-Theanine 200 mg

California Gold Nutrition
A focused 200 mg L-theanine capsule provides a well-aligned calming amount with strong serving value. Its lower serving cost improves affordability over the original stack's high serving cost and limited satisfaction evidence. The focused formula omits GABA, but evidence for swallowed theanine is more direct than for swallowed GABA.
85 Value

Double Strength L-Theanine 200 mg

NOW
A meaningful 200 mg L-theanine amount supports calm focus in a simple capsule with strong practical value. The combination of a meaningful dose and practical serving cost is better balanced than the original stack's high serving cost and limited satisfaction evidence. The focused formula omits GABA, but evidence for swallowed theanine is more direct than for swallowed GABA.
83 Value

GABA 500 mg

Nutricost
A clearly disclosed 500 mg GABA amount with a small vitamin B6 addition provides concise calming support at very low serving cost. The combination of a meaningful dose and practical serving cost is better balanced than the original stack's high serving cost and limited satisfaction evidence. Oral GABA has uncertain brain availability and may cause drowsiness, especially with alcohol, sleep aids, or other sedating products.
85 Value

L-Theanine 150 mg

Solgar
A useful 150 mg Suntheanine amount combines branded ingredient identity with a streamlined single-active design. The combination of a meaningful dose and practical serving cost is better balanced than the original stack's high serving cost and limited satisfaction evidence. The focused formula omits GABA, but evidence for swallowed theanine is more direct than for swallowed GABA.
Report alternatives

Sources

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

  1. 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
  2. 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
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  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 participantsMental Focus Cognitive Support forTheanine
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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
  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