Product Image

Steel-Libido RED

Irwin Naturals
4.4
★ ★ ★ ★ ★
(1292 ratings)
Theobromine 100 mg
Theanine 100 mg
Citrulline 1500 mg
Ginkgo
Protein (unspecified) 4 Gram(s)
Product Image
Score73
A broad libido and focus stack with useful ginkgo, theanine, and theobromine amounts. Modest citrulline and missing botanical standardization limit confidence.
How scoring works
Quantity:150 Softgel(s) • (37 servings)
Goals:
Mental Focus

Score 73

A broad libido and focus stack with useful ginkgo, theanine, and theobromine amounts. Modest citrulline and missing botanical standardization limit confidence.
How scoring works
$44.99($1.21 per serving)
iHerb
$ 44.99
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$ 44.99
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Analysis

Ginkgo, 100 mg L-theanine, 100 mg theobromine, velvet bean, ginseng, and 1,500 mg L-citrulline provide broad circulation and alertness support. The combination has credible mental-focus relevance even though the product is built primarily for sexual performance.

Ginkgo does not disclose active markers or ginkgolic-acid limits, and velvet bean does not state its L-DOPA yield. Ginseng is modest and unstandardized, while the citrulline amount is low compared with focused performance formulas.

The larger package improves recurring value for adults who want this exact libido-and-focus blend. It remains unsuitable for bedtime, vision-specific use, or anyone who cannot safely combine ginkgo and dopaminergic botanicals with their medicines.

Who is it for
  • Adults seeking circulation and libido support
  • Users wanting mild stimulant-like focus without caffeine
  • People who value a larger package for ongoing use
Best for
  • Daytime focus as a secondary use
  • Circulation support
  • Libido-oriented supplementation

Pros

  • Ginkgo, theanine, and theobromine reach useful amounts
  • Includes several circulation pathways
  • Larger package improves serving value

Cons

  • Citrulline is below a strong performance amount
  • Botanical active markers are missing
  • Libido oils add little to cognitive goals

Warnings

  • Ginkgo may increase bleeding risk with anticoagulant or antiplatelet medicines
  • Velvet bean may interact with levodopa and other dopamine-active medicines
  • Theobromine, ginseng, and mucuna may interfere with sleep or aggravate anxiety

Nutrient quality

69 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

82 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

54 Moderate impact

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

Report analysis

Goals

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

Ginkgo, L-theanine, theobromine, velvet bean, and ginseng provide a surprisingly broad focus stack despite the libido positioning. The combination spans cerebral blood flow, calm alertness, mild stimulation, and neurotransmitter support.

Ginkgo, theanine, and theobromine reach useful amounts, while ginseng and velvet bean lack potency-marker disclosure. Ginkgo may increase bleeding risk for people using anticoagulant or antiplatelet medicines.

Study evidence
Ginkgo Supportive 28 studies
Theanine Supportive 19 studies
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
Productivity Boost
Impact
Moderate effect
C+ Goal FitC- Strength of SupportC+ CoverageD+ Formula Quality
Theanine · 100 mg

Ginkgo, L-theanine, theobromine, velvet bean, and ginseng provide several plausible routes to alertness and focus. Theanine may temper the mild stimulant effect while ginkgo supports cognitive circulation.

Velvet bean activity and most botanical standardization are not disclosed, so the actual nootropic strength is uncertain. The libido-focused oils and circulation ingredients make productivity a secondary use.

Study evidence
Ginkgo Supportive 20 studies
Ginkgo Supportive 12 studies
Theanine Supportive 5 studies
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
Energy
Impact
Moderate effect
D+ Goal FitC- Strength of SupportD+ CoverageC Formula Quality

Citrulline and ginseng offer limited stamina relevance inside a libido-focused formula. Citrulline is below common performance dosing and the ginseng amount is modest.

Principal amounts are disclosed, but the extract standardization is incomplete. The formula lacks caffeine, creatine, CoQ10, or focused B-vitamin support.

Study evidence
Citrulline No effect 14 studies
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
Impact
Moderate effect
D+ Goal FitC- Strength of SupportC CoverageF Formula Quality

L-theanine and velvet bean extract provide limited mood relevance through calming and dopamine-related pathways. Ginkgo, ginseng, and theobromine serve the libido and performance purpose more than emotional balance.

The 100 mg L-theanine amount is useful, but the label does not show how much active L-DOPA the velvet bean supplies. Theobromine may be activating for sensitive users, which works against a calming goal.

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
400 mg
Ginkgo extract
120 mg
L-Theanine
100 mg
Theobromine
100 mg
Asian Ginseng extract
80 mg
Cayenne powder
60 mg
Superoxide Dismutase
50 mg
BioPerine Complex
6 mg
Men 18–50 Women
Report overview
Theobromine · 100 mg OverallScore88
A Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyC Value

The standalone theobromine amount reaches the effective range and is clearly stated. Liquid softgel delivery is practical, but the excipient profile is not available for a clean-label judgment. The broader botanical formula offers reasonable value near the collection median.

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.

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, leaving ingredient quality uncertain beyond the chemical form. The larger package slightly improves serving cost, but cost per gram of active citrulline remains poor.

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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. Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis.
    Vårvik FT; Bjørnsen T; Gonzalez AM · International journal of sport nutrition and exercise metabolism · 2021
    Meta-analysis137 participants8 studies pooledEnergy forCitrulline
  28. Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study.
    Suzuki T; Morita M; Kobayashi Y; Kamimura A · Journal of the International Society of Sports Nutrition · 2016
    Randomized trial22 participantsEnergy forCitrulline
  29. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness.
    Pérez-Guisado J; Jakeman PM · Journal of strength and conditioning research · 2010
    Randomized trial41 participantsEnergy forCitrulline
  30. Citrulline/malate promotes aerobic energy production in human exercising muscle.
    Bendahan D; Mattei JP; Ghattas B; Confort-Gouny S; Le Guern ME; Cozzone PJ · British journal of sports medicine · 2002
    Single-arm trial18 participantsEnergy forCitrulline
  31. The Effect of Citrulline Malate Supplementation on Muscle Fatigue Among Healthy Participants.
    Farney TM; Bliss MV; Hearon CM; Salazar DA · Journal of strength and conditioning research · 2019
    Randomized trial12 participantsEnergy forCitrulline
  32. 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
  33. 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
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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
  39. 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
  40. 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
  41. 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
  42. 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
  43. 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
  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. 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