Product Image

Steel-Libido RED

Irwin Naturals
4.4
★ ★ ★ ★ ★
(1298 ratings)
Theanine 100 mg
Theobromine 92 mg
Citrulline 1500 mg
Ginkgo
Protein (unspecified) 4 Gram(s)
Product Image
Score72
Useful ginkgo, theanine, and circulation ingredients give the libido formula credible daytime focus support. Missing potency markers and important medication interactions keep the blend difficult to predict.
How scoring works
Quantity:75 Softgel(s) • (18 servings)
Goals:
Mental Focus
Productivity Boost

Score 72

Useful ginkgo, theanine, and circulation ingredients give the libido formula credible daytime focus support. Missing potency markers and important medication interactions keep the blend difficult to predict.
How scoring works

Also available as

1 option
100.00mg • 150 servings 100.00mg • 150 Softgel(s) • 37 servings $44.99 ($1.21 per serving)
$24.99($1.38 per serving)
Pure Formulas
$ 24.99
iHerb
$ 24.99
Vitacost
$ 24.99
Report prices

Analysis

L-citrulline, ginkgo, L-theanine, theobromine, velvet bean, and ginseng cover blood flow, calm alertness, mild stimulation, and dopamine-related pathways. The 120 mg ginkgo and 100 mg theanine amounts are practical, while 1,500 mg citrulline reaches only the lower edge of maintenance use.

Ginkgo lacks active-marker and ginkgolic-acid disclosure, and velvet bean does not state its L-DOPA content. Ginseng is modest and unstandardized, while a four-softgel serving offers poor citrulline efficiency.

The formula best fits adults seeking libido-oriented circulation with some daytime focus support. Theobromine, mucuna, and ginseng conflict with bedtime use, and ginkgo plus dopaminergic velvet bean require careful medication screening.

Who is it for
  • Adults seeking libido-oriented circulation support
  • Users wanting mild daytime stimulation without added caffeine
  • People who can review medication interactions carefully
Best for
  • Daytime circulation support
  • Mental focus as a secondary benefit
  • Libido-focused supplementation

Pros

  • Useful ginkgo and theanine amounts
  • Covers circulation and calm-alertness pathways
  • Clearly lists individual ingredient weights

Cons

  • Citrulline amount is modest
  • Ginkgo, mucuna, and ginseng lack potency markers
  • Four-softgel serving has weak citrulline value

Warnings

  • Ginkgo may increase bleeding tendency with anticoagulant or antiplatelet medicines
  • Mucuna can interact with levodopa, dopamine-active medicines, and some psychiatric medicines
  • Theobromine and ginseng may disturb sleep or worsen jitteriness in sensitive users

Nutrient quality

70 High impact

Citrulline, theanine, ginkgo, velvet bean, and mild stimulants form a broad libido and performance blend. Some core amounts are useful, while other additions are modest.

Ingredient transparency

83 Highest impact

Active amounts are individually disclosed without a proprietary blend. Several extract standards, complete directions, and non-active ingredients remain unavailable.

Customer satisfaction

83 Highest impact

The aggregate rating is generally favorable and has substantial review volume. No specific comments are supplied, so repeated complaints and purpose alignment cannot be confirmed directly.

Value for money

49 Lower impact

Value is limited for the dose quality and formula focus. Several small additions weaken effective serving value.

Report analysis

Goals

Mental Focus
Mental Focus
Impact
High effect
B+ Goal FitB- Strength of SupportB+ CoverageB- Formula Quality
Theanine · 100 mg

Ginkgo, L-theanine, theobromine, velvet bean, and ginseng cover blood flow, calm alertness, stimulation, and neurotransmitter support. Although marketed for libido, the disclosed stack has substantial mental-focus relevance.

Ginkgo and theanine reach useful amounts, while theobromine is moderate and ginseng lacks standardization details. Ginkgo may increase bleeding risk for people using anticoagulant or antiplatelet medicines.

Study evidence
Ginkgo Supportive 28 studies
Theanine Supportive 19 studies
Productivity Boost
Productivity Boost
Impact
High effect
B- Goal FitC+ Strength of SupportB- CoverageC+ Formula Quality
Theanine · 100 mg

Theanine, ginkgo, theobromine, and ginseng provide a plausible mix of calm attention, circulation, and mild stimulation. Productivity support is secondary because the formula is designed for libido and physical arousal.

Theanine and ginkgo reach useful amounts, while ginseng is modest and ginkgo lacks marker standardization. Ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines, and theobromine may disturb sleep in sensitive users.

Study evidence
Ginkgo Supportive 20 studies
Ginkgo Supportive 12 studies
Theanine Supportive 5 studies
Brain Health
Brain Health
Impact
Moderate effect
C Goal FitC+ Strength of SupportC CoverageD+ Formula Quality

Ginkgo and theanine provide real but secondary brain-health support in a formula designed for another purpose. Mucuna and ginseng add neurotransmitter and fatigue-related pathways, though their active potency is not disclosed.

The lead cognitive ingredients reach useful amounts, but the wider blend is not optimized for sustained memory or neuroprotection. Ginkgo may increase bleeding concern with anticoagulant or antiplatelet medicines.

Study evidence
Ginkgo Supportive 90 studies
Theanine Supportive 17 studies
Cardiovascular Support
Cardiovascular Support
Impact
Moderate effect
C Goal FitC Strength of SupportC- CoverageC Formula Quality
Citrulline · 1500 mg

Citrulline, ginkgo, and theobromine form a coherent circulation-focused combination. Their mechanisms may support nitric oxide production and peripheral blood flow.

The citrulline amount is modest and ginkgo lacks active-marker standardization, so dose confidence is limited. Ginkgo may increase bleeding tendency when combined with anticoagulant or antiplatelet medicines.

Study evidence
Citrulline Supportive 33 studies
Theobromine Supportive 5 studies
Cognitive Support
Cognitive Support
Impact
Moderate effect
C- Goal FitC Strength of SupportC- CoverageF Formula Quality
Theanine · 100 mg

Ginkgo and L-theanine provide circulation and calm-focus pathways with disclosed amounts. Both ingredients are relevant to cognition, although the wider product is designed for libido.

The formula lacks a strong memory active, brain lipid, or meaningful neurotransmitter precursor. Numerous sexual-health ingredients dilute the otherwise sensible ginkgo and theanine pairing.

Study evidence
Ginkgo Supportive 87 studies
Theanine Supportive 25 studies
Mood Support
Mood Support
Impact
Moderate effect
D+ Goal FitC- Strength of SupportC CoverageF Formula Quality

L-theanine and velvet bean extract give the libido formula some mood relevance through calming and dopamine-related pathways. Ginkgo, ginseng, and theobromine add stimulation and circulation support rather than a clear emotional-balance focus.

L-theanine is meaningfully dosed, but the velvet bean extract does not disclose its active L-DOPA content. Theobromine may feel activating for sensitive users, making the formula a poor fit when anxious tension is the main concern.

Study evidence
Theanine Supportive 12 studies

Ingredients

IngredientAmount per serving
Calories
40 Calorie(s)
Total Fat
2 Gram(s)
Total Carbohydrates
1 Gram(s)
Protein
4 Gram(s)
L-Citrulline
1500 mg
Medium Chain Triglyceride Oil
1000 mg
Pumpkin Oil
1000 mg
Velvet Bean Extract (Mucuna pruriens Seed Extract)
 400 mg
Ginkgo biloba Leaf Extract
120 mg
L-Theanine
100 mg
Theobromine
92 mg
Asian Ginseng root extract
80 mg
Cayenne powder
60 mg
Superoxide Dismutase
50 mg
BioPerine Complex
6 mg
Men 18–50 Women
Report overview
Theanine · 100 mg OverallScore82
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyD+ Value

The explicitly identified L-theanine is individually disclosed at an effective target dose. Its generic form has no branded source or purity claim, which limits evidence for premium ingredient quality. Theanine is premium on its own, but substantial citrulline, mucuna, and ginkgo improve the wider formula's value.

View ingredientView products
Theobromine · 92 mg OverallScore81
A Active Ingredient Quality & BioavailabilityB+ Dose, Safety & Label TransparencyC Value

Standalone theobromine is fully disclosed, but the amount is better suited to sensitive users or a synergistic formula than maximum effect. The liquid softgel offers practical delivery, although its excipient profile is not supplied. Other botanicals broaden the formula's value despite a serving cost above the collection median.

View ingredientView products
Citrulline · 1500 mg OverallScore62
B- Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyF Value

Pure L-citrulline is clearly disclosed at the lower boundary of the maintenance-dose range. The source and purity standards are not identified, so the label offers little evidence of ingredient quality beyond the chemical form. A four-softgel serving delivers poor cost efficiency for the active amount and may be less convenient than a focused citrulline supplement.

View ingredientView products
Loading alternative details
71 Performance

Anxie-T

LifeSeasons
<p>Compared with the original, it retains Theobromine, and Theanine and remains aligned with sleep support, and stress relief. Theanine, ashwagandha, GABA, kava, and magnesium taurate create a broad calming formula, but several doses are modest. Kava adds a liver-injury risk and should not be combined with alcohol or other sedatives.</p>
61 Performance

Nitric Oxide Pre-Sport With L-Citrulline

Irwin Naturals
<p>Compared with the original, it retains Ginkgo, Theanine, and Citrulline and remains aligned with vision support. The performance blend discloses its main actives, but citrulline, theanine, and ginkgo are modest for their intended roles and extract strength is not fully defined. Ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines, while yerba mate may add stimulant effects.</p>
73 Performance

Nitrosurge Shred Orange Pineapple

Jacked Factory JF
<p>Compared with the original, it retains Theobromine, and Theanine and remains aligned with mental focus, and productivity boost. Caffeine, theanine, acetyl-L-carnitine, and performance ingredients provide balanced energy and focus support. Citrulline and beta-alanine are below stronger performance amounts.</p>
73 Budget

Steel-Libido RED

Irwin Naturals
<p>It lowers recurring cost while retaining Ginkgo, Theobromine, and Theanine from the original's ingredient focus. Citrulline, theanine, ginkgo, velvet bean, and mild stimulants form a broad libido and performance blend. Value is limited for the effective serving.</p>
58 Budget

Nitro-T

LifeSeasons
<p>It lowers recurring cost while retaining Ginkgo, Theanine, and Citrulline from the original's ingredient focus. Theanine and moderate caffeine provide a useful calm-alertness pairing, but kava conflicts with the stimulant ingredients and several performance actives are lightly dosed. Kava may cause drowsiness and carries a rare liver-safety concern, while ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines.</p>
74 Budget

Nitrosurge Shred Black Cherry

Jacked Factory
<p>It lowers recurring cost while retaining Theobromine, and Theanine from the original's ingredient focus. Caffeine, theanine, acetyl-L-carnitine, and performance ingredients provide balanced energy and focus support. Citrulline and beta-alanine are below stronger performance amounts.</p>
76 Value

Brain Awake

Irwin Naturals
<p>It combines a lower recurring cost with Theanine, supporting a practical value case against the original. Bacopa, branded L-theanine, modest caffeine, and holy basil create a coherent daytime formula for calm alertness and cognitive support. Caffeine may cause jitteriness or disrupt sleep in sensitive users, especially when taken late or combined with other stimulants.</p>
68 Value

NitroSurge Pre-Workout Blue Raspberry

Jacked Factory
<p>It combines a lower recurring cost with Theobromine, and Theanine, supporting a practical value case against the original. The disclosed performance blend coherently targets blood flow, endurance, and alertness, though several core amounts are moderate rather than full strength. Missing flavor-system ingredients and complete directions further limit confidence.</p>
73 Value

Metabolism Weight Management

LifeSeasons
<p>It combines a lower recurring cost with Theobromine, and Theanine, supporting a practical value case against the original. Standardized green tea and green coffee extracts create a relevant metabolism-focused core, with chromium and mild stimulant support around them. The concentrated green tea extract may be poorly tolerated on an empty stomach, while undisclosed caffeine and unclear duplicate marker entries limit confidence.</p>
Report alternatives

Sources

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

  1. 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
  2. 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
  3. 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
  4. 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
  5. 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
  6. 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 forTheanine
  7. 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 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 pooledBrain Health Cognitive Support Mental Focus forTheanine
  9. 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
  10. 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
  11. Does l-citrulline supplementation and watermelon intake reduce blood pressure in middle-aged and older adults? A systematic review and meta-analysis of randomized controlled trials.
    Luo P; Chen J; Liu K; Zhang J · Clinical nutrition ESPEN · 2025
    Meta-analysis415 participants15 studies pooledCardiovascular Support forCitrulline
  12. Micronutrient Supplementation to Reduce Cardiovascular Risk.
    An P; Wan S; Luo Y; Luo J; Zhang X; Zhou S; Xu T; He J; Mechanick JI; Wu WC; Ren F; Liu S · Journal of the American College of Cardiology · 2022
    Meta-analysis883,627 participants884 studies pooledCardiovascular Support forCitrulline
  13. l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans.
    Bailey SJ; Blackwell JR; Lord T; Vanhatalo A; Winyard PG; Jones AM · Journal of applied physiology (Bethesda, Md. : 1985) · 2016
    Randomized trial10 participantsCardiovascular Support forCitrulline
  14. Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women.
    Maharaj A; Fischer SM; Dillon KN; Kang Y; Martinez MA; Figueroa A · Nutrients · 2022
    Randomized trial25 participantsCardiovascular Support forCitrulline
  15. Short-term effects of L-citrulline supplementation on arterial stiffness in middle-aged men.
    Ochiai M; Hayashi T; Morita M; Ina K; Maeda M; Watanabe F; Morishita K · International journal of cardiology · 2012
    Randomized trial15 participantsCardiovascular Support forCitrulline
  16. Effect of cocoa and theobromine consumption on serum HDL-cholesterol concentrations: a randomized controlled trial.
    Neufingerl N; Zebregs YE; Schuring EA; Trautwein EA · The American journal of clinical nutrition · 2013
    Randomized trial152 participantsCardiovascular Support forTheobromine
  17. The Effect of Theobromine Supplementation on HDL-c Subclasses (HDL-c2, HDL-c3), HDL-c2/HDL-c3 Ratio, and Gene Expression of PPAR-α and Sirt1 in Subjects With Metabolic Syndrome: A Randomized Controlled Clinical Trial.
    Sharifi-Zahabi E; Dastafkan Z; Asadi A; Hosseini-Baharanchi FS; Rezvani N; Yari S; Shidfar F · Food science & nutrition · 2025
    Randomized trial80 participantsCardiovascular Support forTheobromine
  18. Relationships between consumption of theobromine in cocoa products and cardiovascular risk factors in 2015-2020 National health and nutrition examination survey.
    Ponsuporn W; Naumovski N; McKune AJ; Khemacheewakul J; Leksawasdi N; Rachtanapun P; Taesuwan S · European journal of nutrition · 2026
    Cross-sectional study8,531 participantsCardiovascular Support forTheobromine
  19. The acute effects on duodenal gene expression in healthy men following consumption of a low-fat meal enriched with theobromine or fat.
    Smolders L; Mensink RP; Boekschoten MV; de Ridder RJJ; Plat J · Scientific reports · 2018
    Randomized trial8 participantsCardiovascular Support forTheobromine
  20. Theobromine supplementation in combination with a low-calorie diet improves cardiovascular risk factors in overweight and obese subjects with metabolic syndrome: a randomized controlled trial.
    Sharifi-Zahabi E; Rezvani N; Hajizadeh-Sharafabad F; Hosseini-Baharanchi FS; Shidfar F; Rahimi M · Food & function · 2023
    Randomized trial80 participantsCardiovascular Support forTheobromine
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  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 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 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 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. [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
  40. 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
  41. 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
  42. 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
  43. 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
  44. 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
  45. 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
  46. 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