Caffeine
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Caffeine. Adenosine antagonist with strong evidence for cognitive and physical performance.
How it works. Competitive antagonist at adenosine A1/A2A receptors, increasing dopamine and NE.
What the research supports. 2 graded claims. Strongest: Improves endurance and power output ~3–6% (strong).
How much to take. Typical dose: 3–6 mg/kg pre-workout; ≤400 mg/d. Not within 8h of bedtime.
Side effects and interactions. 2 medication interactions listed. Serious: Arrhythmia at very high doses (>800 mg acute).
Stacking. Pairs well with L-Theanine.
Common forms. Available as Caffeine anhydrous, Coffee, Pre-workout.
Key studies. 9 studies cited. The strongest are listed with links to PubMed.
Community. Experiences from people who have tried Caffeine. Anecdotes are not medical advice.
Caffeine. Adenosine antagonist with strong evidence for cognitive and physical performance.
What it is
Adenosine antagonist with strong evidence for cognitive and physical performance.
Food sources
Goals
How it works
Competitive antagonist at adenosine A1/A2A receptors, increasing dopamine and NE.
Pathways
- Adenosine antagonism
Effects
- ↑Alertness & focus increases
- ↑Power output & endurance increases
What the research supports
Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.
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Side effects & interactions
Common side effects
- Jitter
- Insomnia
- Anxiety
Serious
- Arrhythmia at very high doses (>800 mg acute)
Medication interactions
Additive.
Caffeine increases lithium clearance.
Check any supplement–medication combination with your pharmacist before starting.
Common forms
- Caffeine anhydrous
- Coffee
- Pre-workout
Key studies
9 studies cited in total.
3–6 mg/kg improves endurance, power, and cognition.
Opens current human and preclinical literature matching Caffeine and "Improves endurance and power output ~3–6%". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Caffeine and "Improves vigilance and reaction time". Filter by RCT, meta-analysis, or year on the results page.
Discussion
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