Caffeine
1,3,7-Trimethylxanthine
Stimulant
Nootropic
A
T1 Full
Acute
Most widely used psychoactive substance. Blocks adenosine receptors to promote wakefulness.
Mechanism of Action
Competitive antagonist at adenosine A1 and A2A receptors. Increases dopamine signaling indirectly.
Usage Tips
- Combine with L-theanine (2:1 ratio) for smooth focus
- Avoid after 2pm to protect sleep quality
- Tolerance builds quickly - consider cycling
Contraindications
- Severe anxiety disorders
- Uncontrolled hypertension
- Cardiac arrhythmias
Performance Profile
Physical Energy
A+4
Mental Stamina
A+3
Alertness
A+4
Motivation
A+3
Dosage
50mg
min
100mg
400mg
max
Timing
Best time
Morning
15 min
onset
4 hr
duration
Half-life
5 hrSafety & Legal
9/10
Well-tolerated
Legal Status
OTC
US & EU
mild
moderate
severe
Jitteriness
1-10%mild
Increased heart rate
1-10%mild
Insomnia
1-10%moderate