Focus & Mental Energy (work/study)
Adults wanting sharper attention and less mental fatigue during desk work.
focus
productivity
improve alertness
sustain attention
reduce mental fatigue
Core stack
Caffeine (low–moderate)
A
Form: coffee/tablet
Dose: 1–3 mg/kg
As needed in 1–2 sittings; avoid within 8 h of bedtime
Occasional/PRN
Why: Clear enhancement of alertness/attention at modest doses.
L-theanine + caffeine
B
Form: capsule
Dose: theanine mg: 100 · caffeine mg: 50
Co-ingest at start of task
Occasional/PRN
Why: Meta-analyses show improved attention and reduced jitter when combined with caffeine.
Not recommended
- High-dose stimulant blends: Unclear dosing; safety/quality issues.
Monitoring
- Caffeine timing vs. sleep
- Anxiety/jitters