Stimulant · C8H10N4O2 · 194.19 g/mol · CAS 58-08-2
Caffeine antagonizes adenosine receptors, increases dopamine signaling, and is the most thoroughly studied legal stimulant on the planet — but it’s not the only option anymore.
Caffeine blocks adenosine A1 and A2A receptors, preventing the buildup of adenosine that produces drowsiness. It indirectly elevates dopamine and norepinephrine, increases cortisol modestly, and has a half-life of 5-6 hours in most adults (longer in slow CYP1A2 metabolizers). About 80-84% of ingested caffeine is metabolized to paraxanthine, which is responsible for much of caffeine’s subjective effect.
100-200mg per serving. Daily intake under 400mg is generally considered safe for healthy adults (FDA).
Caffeine is well-tolerated by most adults but can cause anxiety, insomnia, GI upset, and elevated heart rate, especially in slow metabolizers or above 400mg/day. Tolerance develops within days. Pregnant individuals should limit intake to 200mg/day per ACOG.
Paraxanthine is the molecule caffeine becomes in your liver — minus much of the anxiety, jitter, and long half-life. Leading with paraxanthine gives you the focus without the trade-offs.
Caffeine produces physical dependence and tolerance, and abrupt cessation causes withdrawal symptoms (headache, fatigue) for 2-7 days. It is not classified as an addictive drug in the clinical sense.
The FDA cites 400mg/day as the upper bound for healthy adults. Single doses above 200mg are more likely to produce anxiety and cardiovascular side effects.
These statements have not been evaluated by the FDA. Plopii products are not intended to diagnose, treat, cure, or prevent any disease.