Quick Reference
- Scientific Rating
-
4.9/ 5.0
- Primary Mechanism
- Adenosine receptor antagonism
- Standardized Form
- Caffeine Anhydrous or natural extracts (e.g., Green Tea, Coffee Bean)
Caffeine is a naturally occurring xanthine alkaloid found in coffee, tea, and guarana, and remains the most widely studied and consumed psychoactive compound in the world. It works primarily by blocking adenosine receptors in the brain, a mechanism that reduces the perception of fatigue and increases alertness, dopamine signaling, and reaction time. Its effects are dose-dependent and influenced heavily by individual tolerance, genetics affecting caffeine metabolism, and habitual intake, which is why standardized dosing in supplement formulas is common. Because of its stimulant profile, caffeine is frequently paired with calming compounds like L-theanine to offset jitteriness while preserving alertness.
Table of Contents
Clinical Summary
One of the most extensively studied cognitive and physical ergogenic aids. It reliably improves alertness, vigilance, and endurance by blocking adenosine, a neurotransmitter that promotes sleep.
Dosage Guidelines
100-200mg for general cognitive arousal; 3-6mg/kg of body weight for physical performance enhancement. Best cycled to avoid tolerance.
Safety & Side Effects
Insomnia, jitteriness, increased heart rate, and mild anxiety in high doses or sensitive individuals.
Known Interactions
Interacts with ephedrine, MAOIs, and certain cardiovascular medications. Can accelerate the clearance of lithium.
Scientific References
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Medical Disclaimer
The information provided in this clinical review is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
*These statements have not been evaluated by the Food and Drug Administration (FDA). This product or ingredient is not intended to diagnose, treat, cure, or prevent any disease.
Always consult your physician or other qualified health provider with any questions you may have regarding a medical condition, or before beginning any new diet, fitness, supplement, or treatment regimen, especially if you have pre-existing medical conditions or are taking prescribed medications.
