Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.
- 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 participantsflagBrain Health flagSleep Support flagCognitive Support flagStress Relief forscienceTheanine
- 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 participantsflagSleep Support flagStress Relief forscienceTheanine
- 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 pooledflagSleep Support forscienceTheanine
- Theanine maintains sleep quality in healthy young women by suppressing the increase in caffeine-induced wakefulness after sleep onset.
Baba Y; Takihara T; Okamura N · Food & function · 2023
Clinical trialflagSleep Support forscienceTheanine
- 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 participantsflagStress Relief forscienceTheanine
- 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 pooledflagCognitive Support flagBrain Health flagMental Focus forscienceTheanine
- 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 participantsflagCognitive Support flagBrain Health forscienceTheanine
- 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 participantsflagCognitive Support flagProductivity Boost forscienceTheanine
- 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 trialflagBrain Health flagStress Relief forscienceTheanine
- 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 trialflagBrain Health flagMental Focus flagProductivity Boost forscienceTheanine
- 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 participantsflagCognitive Support forscienceTheanine
- Acute effects of theanine, caffeine and theanine-caffeine combination on attention.
Kahathuduwa CN; Dassanayake TL; Amarakoon AMT; Weerasinghe VS · Nutritional neuroscience · 2018
Clinical trial20 participantsflagCognitive Support flagMental Focus forscienceTheanine
- The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression.
Al Khalifah R; Alsheikh R; Alnasser Y; Alsheikh R; Alhelali N; Naji A; Al Backer N · Systematic reviews · 2021
Meta-analysis20 studies pooledflagCognitive Support forscienceVitamin D
- Vitamin D Supplementation Improves Cognitive Function Through Reducing Oxidative Stress Regulated by Telomere Length in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized Controlled Trial.
Yang T; Wang H; Xiong Y; Chen C; Duan K; Jia J; Ma F · Journal of Alzheimer's disease : JAD · 2021
Randomized trial183 participantsflagCognitive Support forscienceVitamin D
- Effects of vitamin D supplementation on cognitive function and blood Aβ-related biomarkers in older adults with Alzheimer's disease: a randomised, double-blind, placebo-controlled trial.
Jia J; Hu J; Huo X; Miao R; Zhang Y; Ma F · Journal of neurology, neurosurgery, and psychiatry · 2020
Randomized trial210 participantsflagCognitive Support forscienceVitamin D
- Dietary vitamin D intake and 2-year changes in cognitive function in older adults with overweight or obesity and metabolic syndrome.
Vázquez-Lorente H; Ni J; Paz-Graniel I; Toledo E; Corella D; Castañer O; Martínez JA; Alonso-Gómez ÁM; Wärnberg J; Vioque J; Romaguera D; López-Miranda J; Estruch R; Tinahones FJ; Lapetra J; Serra-Majem L; Bouzalmate-Hajjaj A; Tur JA; Pérez RMM; Fanlo M; Delgado-Rodríguez M; Bustelo AB; Vidal J; Vázquez C; Daimiel L; Ros E; Fernández-Aranda F; Rognoni T; Babio N; Asensio EM; Pérez-Vega KA; Garcia-Rios A; Compañ-Gabucio L; Cueto-Galán R; Zulet MA; Nafria M; Casas R; Cano-Ibáñez N; Tojal-Sierra L; Gómez-Pérez AM; Goñi N; Sorli JV; Zomeño MD; Arenas-Larriva AP; Jiménez-Sellés P; Basterra-Gortari J; Fitó M; Salas-Salvadó J · GeroScience · 2025
Cohort study5,454 participantsflagCognitive Support forscienceVitamin D
- Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program.
Melough MM; McGrath M; Palmore M; Collett BR; Kerver JM; Hockett CW; Schmidt RJ; Kelly RS; Lyall K; Zhao Q; Hipwell AE; Korrick SA; Gilbert-Diamond D; Weiss ST; Chu SH; Mirzakhani H; Porter JM; Sathyanarayana S; ECHO Cohort Consortium · The American journal of clinical nutrition · 2025
Cohort study912 participantsflagCognitive Support forscienceVitamin D
- 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 participantsflagMental Focus flagProductivity Boost flagStress Relief forscienceTheanine
- 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 participantsflagMental Focus forscienceTheanine
- 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 participantsflagMood Support forscienceTheanine
- 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 participantsflagMood Support flagStress Relief forscienceTheanine
- 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 pooledflagMood Support forscienceTheanine
- 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 participantsflagMood Support flagStress Relief forscienceTheanine
- 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 participantsflagMood Support forscienceTheanine
- Meta-analysis of the effect of vitamin D on depression.
Wang L; Su S; Liu Y · Frontiers in psychiatry · 2025
Meta-analysis20 studies pooledflagMood Support forscienceVitamin D
- A randomized controlled trial of vitamin D supplementation on perinatal depression: in Iranian pregnant mothers.
Vaziri F; Nasiri S; Tavana Z; Dabbaghmanesh MH; Sharif F; Jafari P · BMC pregnancy and childbirth · 2017
Randomized trial169 participantsflagMood Support forscienceVitamin D
- Prospective associations between vitamin D and depression in middle-aged adults: findings from the UK Biobank cohort.
Ronaldson A; Arias de la Torre J; Gaughran F; Bakolis I; Hatch SL; Hotopf M; Dregan A · Psychological medicine · 2022
Cohort study139,128 participantsflagMood Support forscienceVitamin D
- Association Between Low Vitamin D Levels and Depression: A Systematic Review and Meta-Analysis.
Karim S; Natche J; Babli SA; Avinash; Matakhov D; Ferdous S; Jeyakkodi H; Alamu OS; Rizwanullah U; Hameed SA · Cureus · 2026
Meta-analysis49,931 participants15 studies pooledflagMood Support forscienceVitamin D
- Vitamin D Alleviates Anxiety and Depression in Elderly People with Prediabetes: A Randomized Controlled Study.
Zaromytidou E; Koufakis T; Dimakopoulos G; Drivakou D; Konstantinidou S; Rakitzi P; Grammatiki M; Manthou E; Notopoulos A; Iakovou I; Gotzamani-Psarrakou A; Kotsa K · Metabolites · 2023
Randomized trial90 participantsflagMood Support flagStress Relief forscienceVitamin D
- 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 pooledflagProductivity Boost forscienceTheanine
- Effects of L-theanine on cognition, mood and sleep: evidence from human trials.
Cotter J; Kilpatrick HE · Frontiers in nutrition · 2026
Narrative reviewflagProductivity Boost forscienceTheanine
- 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 participantsflagSleep Support forscienceTheanine
- In Search of a Safe Natural Sleep Aid.
Rao TP; Ozeki M; Juneja LR · Journal of the American College of Nutrition · 2016
Narrative reviewflagSleep Support forscienceTheanine
- Effects of an 8-week high-dose vitamin D supplementation on fatigue and neuropsychiatric manifestations in post-COVID syndrome: A randomized controlled trial.
Charoenporn V; Tungsukruthai P; Teacharushatakit P; Hanvivattanakul S; Sriyakul K; Sukprasert S; Kamalashiran C; Tungsukruthai S; Charernboon T · Psychiatry and clinical neurosciences · 2024
Randomized trial80 participantsflagStress Relief forscienceVitamin D
- The Influence of Vitamin D Intake and Status on Mental Health in Children: A Systematic Review.
Głąbska D; Kołota A; Lachowicz K; Skolmowska D; Stachoń M; Guzek D · Nutrients · 2021
Systematic review24 studies pooledflagStress Relief forscienceVitamin D
- Vitamin D3 enhances mood in healthy subjects during winter.
Lansdowne AT; Provost SC · Psychopharmacology · 1998
Randomized trial44 participantsflagStress Relief forscienceVitamin D
- Comparative Effects of Etelcalcetide and Maxacalcitol on Serum Calcification Propensity in Secondary Hyperparathyroidism: A Randomized Clinical Trial.
Shoji T; Nakatani S; Kabata D; Mori K; Shintani A; Yoshida H; Takahashi K; Ota K; Fujii H; Ueda S; Nishi S; Nakatani T; Yoshiyama M; Goto K; Hamada T; Imanishi M; Ishimura E; Kagitani S; Kato Y; Kumeda Y; Maekawa K; Matsumura T; Nagayama H; Obi Y; Ohno Y; Sai Y; Sakurai M; Sasaki S; Shidara K; Shoji S; Tsujimoto Y; Yamakawa K; Yasuda H; Yodoi S; Inaba M; Emoto M · Clinical journal of the American Society of Nephrology : CJASN · 2021
Randomized trial326 participantsflagStress Relief forscienceVitamin D