Focus & concentration
108 supplements analyzed and ranked by clinical evidence.
Supplement Evidence
Iron stores↑
Hb↑ 1–4g/dL
Cognition↑
Attention + ADHD symptom relief
2-7 pt improvement
Caffeine: faster attention +RT
Drunk: partial RT rescue
Sleep loss: alertness +RT
Memory/attention +10%
Craving/withdrawal ↓
Task speed ↑
Attention + memory
Alertness + processing speed
Processing speed +8.8
Memory/attention + small gains
Hb/iron ↑, fatigue/QOL
Neuro/cognition +8-13 pts
Focused attention + faster processing
+3.5 IQ, -6.9 BPD
Better attention, memory
Cognition +3.3 pts
Function/behavior better
Attention speed +
Executive/processing +24%
Memory/attention +18%
Iodine status, memory +
Thyroid function, cognition +
Ammonia↓, focus↑
Memory/attention↑
Schizophrenia cognition↑
Alertness + memory
Sleep timing + attention
Attention/memory +
Sleepiness/cognition −
Attention/memory gains
+6 to +10%
Attention faster, steadier
Memory/attention +
EEG gating/immediate focus
+
Memory +5.4
Attention/working memory
Verbal/visual memory
GSH↑, concentration↑
Cognition +26%
Perfusion/working memory↑
Improved memory/attention
Better cognition, 12.2%
Faster processing, +13.0
Memory/attention +p<0.05
Fatigue/motor +p<0.001
Attention/RT +0.07 SD
Alertness/fatigue improved
Executive function +0.06 SD
Attention/memory +significant
Fatigue/cognition +MMSE
Reaction time only
Hydration lifts focus +performance
Dehydration blunts attention -5%
Electrolytes improve cognition +4%
Attention: slower/worse
Dopamine: reduced focus
Attention/memory: +0.35
Homocysteine↓; cognition↑
Speed/attention +13-18s
Memory/executive +11-27%
Attention/fatigue +1.25
Memory/working memory +7.5%
Focus: attention, memory
Focus: +1.7 T-score
Attention/memory +fast
Lower fatigue/stress -4.3
ADHD symptoms -2.25
Attention/memory +7%
+46% reading/spelling
Focus+memory: better
Attention/executive: −
Learning/retention: better
Memory + attention
Alertness +1.6 errors
Focus/attention +5-10%
Concentration under stress
Stroop/working memory ↑
Fatigue/attention, +59%
Memory/executive, +0.84
Lower Trp harms attention
BCAA helps reaction time
Attention + cognition +
Reaction time +
Memory/attention +3–36%
Migraine burden −8w
Memory/attention: better
Focus scores: +3.7
EEG/recall: improved
Better attention/memory
Reduced cognitive decline
Memory/attention/orientation
+ cognition & daily function
Attention/processing +13, −51ms
Memory/concentration improved
Slower cognitive decline
Attention/memory +
Reactivity/recall -118ms
Fatigue down, attention up
~15% antifatigue
Attention/memory improved
Cognition +14.2%
Attention/memory improved
School ability higher
Attention speed+accuracy
Fatigue/stress down
Attention + memory
small gains
Attention + fast RT
Working memory + accuracy
Alertness, -tiredness
Better focus, faster
Lower stress, steadier
Improved Stroop +17%
Better reaction time -14ms
Memory/attention + MoCA
+7-32%
Working memory/reaction time
Attention/memory +
Relaxed alertness
Attention/RT +8.5%
Fatigue↓; vigilance↑
Cognition +0.78
Dementia severity better
ADHD/OCD similar
Attention +RT
Stress -4 to -6
Attention + memory
Concentration + impulsivity
Cognition +4.6
Attention/task-switching improved
RBC AChE -50%
Anxiety ↓; focus unchanged
No cognitive/sedation effect
EEG shift; focus stable
Alertness + speed
Less anxiety, better memory
Alertness: no change
Working memory: +5
Attention + sleep
Anxiety − sleep
Cognition/attention +?
Symptoms -19%
Motivation/attention + recovery
+1.1% WM consolidation
SAM↑, cognition↑
DAT↕, no insulin
Attention + memory
Calmness + recall
Cognition + memory, p<0.05
Psychobehaviour + scores, p<0.05
Memory +7.2
THC effects -78%
EEG preserved
+0.015 gamma
MMSE stable
Memory +BP changes
Executive speed +oxygenation
Cognition + A. muciniphila
SCFAs +42% / +38%
HRV, cognition +
Attention +46%
Memory/cognition mixed
Cortisol/steroids ↑
Ketones + cognition
Inhibitory control, WM
Brain fog, cognition +
Inhibition/plasticity, attention +
MMN changes; focus mixed
CBD +5 vitality, less sleepiness
Cognition + flow better
Working memory decline prevented
Choline/metabolites: focus ↑
+1.23 speed; errors ↓
Attention +47%
Cognition +r0.47
Attention + memory
IQ subtests + recall
Attention + mental fatigue
Delirium risk −11.2%
ATP↑, cognition↑
Sleepiness↓
Attention + significant
Working memory + mood
Psychometrics + EEG
Slow caffeine clearance
Improved attention/performance
+31 h half-life
Cognition +6.25
Memory +0.17
Cognitive +29%
Sleepiness reduced
Attention lapses down
Attention + memory
PFC blood-flow +10%
Processing speed/flexibility
Attention/memory +
Emotion speed +
Speed +6.7%
Stress -9.5
Better mood/focus
+focus, no gains
Memory + fluency
Attention/speed + accuracy
Cognition +10.6%
Attention/reaction time
Protein synthesis
Attention/speed +2h
Memory/language, anxiety down
Hippocampal preservation +0.5%
Less ventricular expansion −2.0%
Alertness +; memory 0
Cognition +; vigilance +
Less sedation, better focus
+10 min, sharper attention
Energy/focus +VAS
Blood pressure +3.4–5.4
Attention/speed +~2
Alertness decline −5.9pp
Perfusion/speed improved
EEG shifts; cognition +
Memory/mood +0.58d, attention mixed
T3↑, T4↓; cognition same
Symptomatic subgroup improved +T3
Attention↑, hyperactivity↓
Oxidative stress↓, GSH/GSSG↑
Executive function ↑
Memory/accuracy ↑
Memory + recall gains
Working-memory errors -
Water +2.2–2.5%; focus up
Psychometric performance improved
Attention,self-control, memory
Improved (NR)
Less mental fatigue, -11.7
Mood-related focus boost, -3.8
Attention, speed, accuracy
Improved focus
Fewer errors
Memory contentment +2.7
Faster movement -10.4 ms
Fewer memory errors -8.5
Lower BP, slower breathing
Respiratory rate -significant
Motor/QoL: similar
AEs +18.5%
Attention timing faster
Impulsivity +50%
Sedation/alertness reversed