Product Image

Nitro-T

LifeSeasons
4.8
★ ★ ★ ★ ★
(45 ratings)
Theanine 200 mg
Citrulline 1000 mg
Tribulus 100 mg
Ginkgo
Ginger
Product Image
Score58
A conflicting stimulant-relaxation blend with modest citrulline, unclear ginkgo dosing, and notable kava risks.
How scoring works
Quantity:90 Capsule(s) • (30 servings)
Goals:
Mental Focus
Cognitive Support

Score 58

A conflicting stimulant-relaxation blend with modest citrulline, unclear ginkgo dosing, and notable kava risks.
How scoring works
$34.99($1.16 per serving)
iHerb
$ 34.99
iHerb
$ 34.99
Report prices

Analysis

The serving supplies 1 g citrulline, 200 mg theanine, 65 mg caffeine, and several botanicals. Kava, ginkgo, tribulus, ginger, ginseng, and muira puama make the formula unusually broad.

Caffeine and kava pull the experience in different directions, while the citrulline amount is modest for a dedicated pump product. Two ginkgo lines each list 60 mg with different markers, so the true extract amount is unclear.

The blend may feel calming and stimulating at once, but it is not a precise sleep, vision, cognition, or testosterone formula. Its interaction burden is high for a general-use supplement.

Who is it for
  • Experienced users who have screened the full formula
  • Adults specifically seeking a mixed energy and relaxation product
Best for
  • Occasional daytime energy
  • Mild circulation support

Pros

  • Provides 200 mg L-theanine
  • Includes 1 g L-citrulline
  • Clearly states 65 mg caffeine

Cons

  • Combines caffeine with kava
  • Ginkgo dose is ambiguous
  • Poor fit for sleep support

Warnings

  • Kava carries a liver-safety concern and should not be combined with alcohol, sedatives, or other products that impair alertness.
  • Ginkgo and ginger may increase bleeding tendency with anticoagulant or antiplatelet medicines.
  • The caffeine amount can disrupt sleep and may not suit stimulant-sensitive users.

Nutrient quality

54 Moderate impact

L-theanine and L-citrulline are clear forms, while ginkgo and tribulus markers lack percentage standardization. Theanine is meaningful, but citrulline, ginkgo, ginseng, and tribulus are modest for targeted use.

Ingredient transparency

77 High impact

Every listed active has an individual amount. Excipients and daily directions are absent from the supplied data, which leaves some label details uncertain.

Customer satisfaction

64 Moderate impact

The aggregate satisfaction average is exceptionally strong, though no detailed feedback is supplied. The limited volume supports only moderate confidence in the aggregate signal.

Value for money

32 Situational impact

A useful theanine dose is offset by conflicting design and modest secondary actives. The serving cost is high relative to the depth of the main performance ingredients.

Report analysis

Goals

Mental Focus
Mental Focus
Impact
High effect
B+ Goal FitB- Strength of SupportB CoverageD Formula Quality
Theanine · 200 mgCaffeine · 65 mg

Caffeine and L-theanine provide a credible calm-alertness pairing, with ginkgo adding modest circulation support. The theanine amount is well targeted, while the caffeine amount is moderate and ginkgo standardization remains unclear.

Kava and several performance herbs make the formula less focused and may counter daytime alertness. Kava can cause drowsiness and has been linked to rare serious liver injury, while ginkgo may raise bleeding risk with anticoagulant or antiplatelet medicines.

Study evidence
Caffeine Supportive 128 studies
Ginkgo Supportive 28 studies
Theanine Supportive 19 studies
Cognitive Support
Cognitive Support
Impact
High effect
B Goal FitC Strength of SupportB CoverageD- Formula Quality
Theanine · 200 mg

L-theanine, caffeine, ginkgo, ginseng, and citrulline address calm focus, alertness, circulation, and performance. Theanine is well dosed, but ginkgo and ginseng are modest or incompletely standardized, while kava adds a sedating pathway that conflicts with stimulation.

Ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines. Kava can cause sedation and has rare liver-safety concerns, making the broad performance blend harder to use routinely.

Study evidence
Ginkgo Supportive 87 studies
Theanine Supportive 25 studies
Productivity Boost
Productivity Boost
Impact
Moderate effect
B- Goal FitC- Strength of SupportB- CoverageD Formula Quality
Theanine · 200 mgCaffeine · 65 mg

Caffeine and L-theanine provide a useful calm-alertness pairing, while ginkgo and ginseng add circulation and fatigue-resilience pathways. The caffeine amount is modest and the botanical doses or marker percentages are too limited for strong depth.

Kava pulls the formula toward relaxation and may conflict with active daytime performance. Ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines, while kava adds a separate liver-safety concern.

Study evidence
Caffeine Supportive 108 studies
Ginkgo Supportive 20 studies
Ginkgo Supportive 12 studies
Theanine Supportive 5 studies
Stress Relief
Stress Relief
Impact
Moderate effect
C+ Goal FitB Strength of SupportC CoverageF Formula Quality
Theanine · 200 mg

L-theanine and kava provide calming support, while caffeine and ginseng add stimulation. The result is geared toward vitality and sexual performance rather than uncomplicated stress relief.

Kava can cause drowsiness and carries a rare liver-injury concern, so it should not be combined casually with alcohol or sedatives. The stimulant-calming mix makes individual response and timing difficult to predict.

Study evidence
Theanine Supportive 16 studies
Brain Health
Brain Health
Impact
Moderate effect
C Goal FitC- Strength of SupportC CoverageD Formula Quality

L-theanine, caffeine, and ginkgo can support alertness, calm focus, and circulation through distinct mechanisms. The product is primarily a performance and libido blend, so brain support is not its sole or clearest purpose.

Theanine is well dosed, but ginkgo is modest and its marker percentages are not disclosed. Kava adds a sedating element that may work against the stimulant goal and makes the formula less coherent for predictable focus.

Study evidence
Ginkgo Supportive 90 studies
Theanine Supportive 17 studies
Mood Support
Mood Support
Impact
Moderate effect
C- Goal FitC- Strength of SupportC CoverageD- Formula Quality

L-theanine, low-dose caffeine, kava, ginkgo, and ginseng combine calm, alertness, and adaptogenic pathways. The 200 mg theanine amount is the strongest mood-relevant feature.

Kava and caffeine create competing sedating and stimulating effects, while ginkgo and ginseng are lightly dosed. Kava can add sedation and carries a rare liver-injury concern, while ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines.

Study evidence
Theanine Supportive 12 studies
Sleep Support
Sleep Support
Impact
Moderate effect
D- Goal FitB- Strength of SupportC CoverageF Formula Quality
Theanine · 200 mg

L-theanine and kava provide calming ingredients, but caffeine, ginseng, ginkgo, and performance actives push the formula toward daytime stimulation. The conflicting design makes it unreliable for sleep despite a meaningful theanine amount.

Kava may add sedation but carries a rare liver-injury concern, especially with alcohol or other liver-stressing substances. The 65 mg caffeine amount can still delay sleep in sensitive users or when taken late.

Study evidence
Theanine Supportive 8 studies

Ingredients

IngredientAmount per serving
L-Citrulline
1000 mg
L-Theanine
200 mg
Tribulus fruit extract (Saponins)
 100 mg
Muira Puama bark extract
100 mg
Ginger
100 mg
Kava Kava root extract (Kavalactones)
 100 mg
Wild Oat straw extract
100 mg
Caffeine (Coffea arabica)
 65 mg
Ginkgo leaf extract (Flavone Glycosides, Terpene Lactones)
 60 mg
Korean Ginseng
50 mg
Men 50+ Gluten Free Men 18–50 Dairy Free Vegetarian
Report overview
Theanine · 200 mg OverallScore82
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyD+ Value

Explicit L-theanine identity confirms the active isomer, but no branded source or purity testing is shown. The clearly disclosed amount falls within the optimal range for calm and focused support. Its multi-ingredient stimulant and botanical context shifts the use toward performance support.

View ingredientView products
Citrulline · 1000 mg OverallScore54
B- Active Ingredient Quality & BioavailabilityC Dose, Safety & Label TransparencyF Value

Pure L-Citrulline is named and its individual amount is disclosed. The 1,000 mg serving is below the common performance range but may offer modest support. Kava and caffeine create a mixed sedative-stimulant profile that may not suit sensitive users.

View ingredientView products
Tribulus (Saponins) · 100 mg OverallScore44
D+ Active Ingredient Quality & BioavailabilityD+ Dose, Safety & Label TransparencyF Value

Fruit extract is a favorable source, but the saponin percentage remains undisclosed. The 100 mg dose is low and offers limited Tribulus potency within the broader blend. The costly serving creates poor value, while kava may add sedation and should not be combined with alcohol or other sedatives.

View ingredientView products
Loading alternative details
73 Performance

Steel-Libido RED

Irwin Naturals
The use of 1.5 g citrulline, 100 mg theanine, 120 mg ginkgo, and 400 mg velvet bean extract provides stronger ingredient focus or dose depth than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Velvet bean, ginkgo, ginseng, theobromine, and BioPerine create meaningful interaction and tolerance concerns.
70 Performance

Clari-T

LifeSeasons
The use of bacopa, measured ginkgo constituents, and 100 mg phosphatidylserine provides stronger ingredient focus or dose depth than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Vinpocetine and a huperzine-bearing clubmoss extract add important interaction and tolerance concerns.
69 Performance

Men's Virility Power

NOW
The use of a long-supply botanical blend with tribulus, ginkgo, epimedium, maca, and ginseng provides stronger ingredient focus or dose depth than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. The ginkgo and tribulus amounts remain small, and several extracts lack complete standardization.
61 Budget

Nitric Oxide Pre-Sport With L-Citrulline

Irwin Naturals
A lower recurring cost and 750 mg citrulline with 50 mg theanine and measured ginkgo constituents improve practical value compared with the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Citrulline and theanine remain modest, and yerba mate may add stimulant effects.
71 Budget

SexEssentials

Natural Factors WS WomenSense
A lower recurring cost and 1 g arginine with tribulus and measured ginkgo constituents improve practical value compared with the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. The ginkgo, tribulus, tongkat ali, and choline amounts or standards are not strong enough for intensive support.
72 Budget

Focus-R

LifeSeasons
A lower recurring cost and 250 mg theanine with methylcobalamin, bacopa, caffeine, and ginkgo improve practical value compared with the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Kava retains a sedation and liver-safety concern, while ginkgo may interact with medicines that reduce clotting.
68 Value

Men's Virility Power

NOW
The combination of an economical botanical blend with tribulus, ginkgo, epimedium, maca, and ginseng offers a better balance of ingredient utility and recurring value than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Key ginkgo and tribulus amounts are modest, so the formula favors breadth over dose depth.
58 Value

Fenugreek RED

Irwin Naturals
The combination of 1.5 g citrulline with fenugreek, ginkgo, tongkat ali, and supporting oil offers a better balance of ingredient utility and recurring value than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Extract standardization is uneven, and ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines.
69 Value

Neuro-T

LifeSeasons
The combination of 250 mg theanine with methylcobalamin, bacopa, caffeine, and several botanicals offers a better balance of ingredient utility and recurring value than the original’s conflicting kava-and-caffeine design and lightly dosed performance botanicals. Kava may compound sedation and has a liver-safety concern, while ginkgo can interact with medicines that reduce clotting.
Report alternatives

Sources

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

  1. 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
  2. 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
  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. 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
  5. L-theanine improves neurophysiological measures of attention in a dose-dependent manner: a double-blind, placebo-controlled, crossover study.
    Dassanayake TL; Kahathuduwa CN; Weerasinghe VS · Nutritional neuroscience · 2022
    Randomized trial27 participantsMental Focus forTheanine
  6. 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 participantsMental Focus Cognitive Support 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. Efficacy and adverse effects of ginkgo biloba for cognitive impairment and dementia: a systematic review and meta-analysis.
    Tan MS; Yu JT; Tan CC; Wang HF; Meng XF; Wang C; Jiang T; Zhu XC; Tan L · Journal of Alzheimer's disease : JAD · 2015
    Meta-analysis2,561 participants9 studies pooledBrain Health forGinkgo
  9. Efficacy of Ginkgo biloba extract EGb 761® in dementia with behavioural and psychological symptoms: A systematic review.
    von Gunten A; Schlaefke S; Überla K · The world journal of biological psychiatry : the official journal of the World Federation of Societies of Biological Psychiatry · 2017
    Meta-analysis1,628 participants4 studies pooledBrain Health Cognitive Support forGinkgo
  10. Ginkgo biloba extract EGb 761 is safe and effective in the treatment of mild dementia - a meta-analysis of patient subgroups in randomised controlled trials.
    Riepe M; Hoerr R; Schlaefke S · The world journal of biological psychiatry : the official journal of the World Federation of Societies of Biological Psychiatry · 2025
    Meta-analysis782 participants4 studies pooledBrain Health Productivity Boost forGinkgo
  11. Ginkgo biloba extract EGb 761® improves cognition and overall condition after ischemic stroke: Results from a pilot randomized trial.
    Cui M; You T; Zhao Y; Liu R; Guan Y; Liu J; Liu X; Wang X; Dong Q · Frontiers in pharmacology · 2023
    Randomized trial201 participantsBrain Health Productivity Boost forGinkgo
  12. Ginkgo biloba extract EGb 761® in dementia with neuropsychiatric features: a randomised, placebo-controlled trial to confirm the efficacy and safety of a daily dose of 240 mg.
    Herrschaft H; Nacu A; Likhachev S; Sholomov I; Hoerr R; Schlaefke S · Journal of psychiatric research · 2012
    Randomized trial410 participantsBrain Health forGinkgo
  13. 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
  14. 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
  15. 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
  16. 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
  17. Efficacy of ginkgo diterpene lactone meglumine on cognitive function in patients with acute ischemic stroke: a predefined exploratory analysis of a multicenter, double-blind, randomized controlled trial.
    Tian X; Xu Q; Xia X; Zhang Y; Meng X; Wang A · Journal of neurology · 2024
    Randomized trial3,163 participantsCognitive Support forGinkgo
  18. A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. North American EGb Study Group.
    Le Bars PL; Katz MM; Berman N; Itil TM; Freedman AM; Schatzberg AF · JAMA · 1997
    Randomized trial309 participantsCognitive Support Productivity Boost forGinkgo
  19. Alleviating neuropsychiatric symptoms in dementia: the effects of Ginkgo biloba extract EGb 761. Findings from a randomized controlled trial.
    Bachinskaya N; Hoerr R; Ihl R · Neuropsychiatric disease and treatment · 2011
    Randomized trial410 participantsCognitive Support forGinkgo
  20. Efficacy and safety of a once-daily formulation of Ginkgo biloba extract EGb 761 in dementia with neuropsychiatric features: a randomized controlled trial.
    Ihl R; Bachinskaya N; Korczyn AD; Vakhapova V; Tribanek M; Hoerr R; Napryeyenko O; GOTADAY Study Group · International journal of geriatric psychiatry · 2013
    Randomized trial410 participantsCognitive Support forGinkgo
  21. 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
  22. Effects of modafinil and caffeine on night-time vigilance of air force crewmembers: A randomized controlled trial.
    Wingelaar-Jagt YQ; Bottenheft C; Riedel WJ; Ramaekers JG · Journal of psychopharmacology (Oxford, England) · 2023
    Randomized trial32 participantsMental Focus forCaffeine
  23. Acute effects of caffeine on attention: a comparison of non-consumers and withdrawn consumers.
    Smith AP; Christopher G; Sutherland D · Journal of psychopharmacology (Oxford, England) · 2013
    Randomized trial70 participantsMental Focus forCaffeine
  24. Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation.
    Wesensten NJ; Killgore WD; Balkin TJ · Journal of sleep research · 2006
    Randomized trial48 participantsMental Focus forCaffeine
  25. Effects of caffeine on mood and performance: a study of realistic consumption.
    Brice CF; Smith AP · Psychopharmacology · 2003
    Clinical trial24 participantsMental Focus forCaffeine
  26. Effects of caffeine or diphenhydramine on visual vigilance.
    Fine BJ; Kobrick JL; Lieberman HR; Marlowe B; Riley RH; Tharion WJ · Psychopharmacology · 1995
    Randomized trial24 participantsMental Focus forCaffeine
  27. Ginkgo biloba Extract EGb 761 in the Treatment of Patients with Mild Neurocognitive Impairment: A Systematic Review.
    Hort J; Duning T; Hoerr R · Neuropsychiatric disease and treatment · 2023
    Systematic review946 participants9 studies pooledMental Focus forGinkgo
  28. Proof of efficacy of the Ginkgo biloba special extract EGb 761 in outpatients suffering from mild to moderate primary degenerative dementia of the Alzheimer type or multi-infarct dementia.
    Kanowski S; Herrmann WM; Stephan K; Wierich W; Hörr R · Phytomedicine : international journal of phytotherapy and phytopharmacology · 2012
    Randomized trial216 participantsMental Focus forGinkgo
  29. Proof of efficacy of the ginkgo biloba special extract EGb 761 in outpatients suffering from mild to moderate primary degenerative dementia of the Alzheimer type or multi-infarct dementia.
    Kanowski S; Herrmann WM; Stephan K; Wierich W; Hörr R · Pharmacopsychiatry · 1996
    Randomized trial216 participantsMental Focus forGinkgo
  30. Ginkgo biloba extract improved cognitive and neurological functions of acute ischaemic stroke: a randomised controlled trial.
    Li S; Zhang X; Fang Q; Zhou J; Zhang M; Wang H; Chen Y; Xu B; Wu Y; Qian L; Xu Y · Stroke and vascular neurology · 2021
    Randomized trial348 participantsMental Focus forGinkgo
  31. Ginkgo biloba in the Aging Process: A Narrative Review.
    Barbalho SM; Direito R; Laurindo LF; Marton LT; Guiguer EL; Goulart RA; Tofano RJ; Carvalho ACA; Flato UAP; Capelluppi Tofano VA; Detregiachi CRP; Bueno PCS; Girio RSJ; Araújo AC · Antioxidants (Basel, Switzerland) · 2024
    Narrative review14 studies pooledMental Focus forGinkgo
  32. 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 participantsMental Focus Productivity Boost Stress Relief forTheanine
  33. 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
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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
  39. Effects of caffeine on alertness.
    Zwyghuizen-Doorenbos A; Roehrs TA; Lipschutz L; Timms V; Roth T · Psychopharmacology · 1990
    Randomized trial24 participantsProductivity Boost forCaffeine
  40. Effects of Different Sources of Low-Dose Caffeine on Mood/Arousal and Cognitive Performance.
    Irwin C; McCartney D; Grant G; Delang N; Bartrim K; Cox GR; Desbrow B · Perceptual and motor skills · 2023
    Randomized trial22 participantsProductivity Boost forCaffeine
  41. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land.
    Lieberman HR; Tharion WJ; Shukitt-Hale B; Speckman KL; Tulley R · Psychopharmacology · 2003
    Randomized trial68 participantsProductivity Boost forCaffeine
  42. A review of caffeine's effects on cognitive, physical and occupational performance.
    McLellan TM; Caldwell JA; Lieberman HR · Neuroscience and biobehavioral reviews · 2017
    Narrative reviewProductivity Boost forCaffeine
  43. Acute caffeine supplementation as a nutrition-based strategy to mitigate sleep-loss-related cognitive and operational performance impairments in military personnel: a systematic review and meta-analysis.
    Wang R; Wang W; Meng L; Hao G; Gu G · Frontiers in nutrition · 2026
    Meta-analysis7 studies pooledProductivity Boost forCaffeine
  44. [Ginkgo biloba extract EGb 761 in the treatment of dementia: evidence of efficacy and tolerability].
    Kasper S; Schubert H · Fortschritte der Neurologie-Psychiatrie · 2009
    Meta-analysis10 studies pooledProductivity Boost forGinkgo
  45. Dietary Flavonoids and Human Cognition: A Meta-Analysis.
    Cheng N; Bell L; Lamport DJ; Williams CM · Molecular nutrition & food research · 2022
    Meta-analysis5,519 participants80 studies pooledProductivity Boost forGinkgo
  46. Limited cognitive benefits in Stage +2 postmenopausal women after 6 weeks of treatment with Ginkgo biloba.
    Elsabagh S; Hartley DE; File SE · Journal of psychopharmacology (Oxford, England) · 2005
    Randomized trial87 participantsProductivity Boost forGinkgo
  47. Efficacy and safety of Ginkgo biloba extract EGb 761 in mild cognitive impairment with neuropsychiatric symptoms: a randomized, placebo-controlled, double-blind, multi-center trial.
    Gavrilova SI; Preuss UW; Wong JW; Hoerr R; Kaschel R; Bachinskaya N; GIMCIPlus Study Group · International journal of geriatric psychiatry · 2015
    Randomized trial160 participantsProductivity Boost forGinkgo
  48. Modulation of cognitive performance following single doses of 120 mg Ginkgo biloba extract administered to healthy young volunteers.
    Kennedy DO; Jackson PA; Haskell CF; Scholey AB · Human psychopharmacology · 2008
    Randomized trial78 participantsProductivity Boost forGinkgo
  49. 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
  50. 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
  51. 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
  52. 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
  53. 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